PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 80 SPACECRAFT_NAME = MAGELLAN TARGET_NAME = VENUS OBJECT = TEXT PUBLICATION_DATE = 1994-06-01 NOTE = "NAV-138 V1.12.2 Software Interface Specification" END_OBJECT = TEXT END Jet Propulsion Laboratory PROJECT MAGELLAN Software Interface Specification NAV-138 LINE OF SIGHT ACCELERATION PROFILE DATA RECORD prepared by Richard Simpson Durand Bldg - Room 232 Stanford University Stanford, CA 94305-4055 Version 1.12.2 11 June 1993 ACRONYMS AND ABBREVIATIONS ANSI American National Standards Institute ASCII American Standard Code for Information Interchange CCSDS Consultative Committee for Space Data Systems CR Carriage Return DEC Digital Equipment Corporation FTP File Transfer Protocol hr hour Hz Hertz IEEE Institute of Electrical and Electronic Engineering int integer IAU International Astronomical Union JPL Jet Propulsion Laboratory J2000 IAU Official Time Epoch K Degrees Kelvin km Kilometers LF Line Feed LOSAPDR Line of Sight Acceleration Profile Data Record LUNRES Gravity analysis program MGN Magellan min minutes mm millimeters MO Mars Observer NAIF Navigation and Ancillary Information Facility NAV Navigation Subsystem/Team ODL Object Definition Language (PDS) PDB Project Data Base PDS Planetary Data System RS Radio Science SCET Space Craft Event Time sec seconds SFDU Standard Formatted Data Unit SIS Software Interface Specification SOPC Science Operations Planning Computer SPK Spacecraft and Planet Kernel Format, from NAIF TBD To Be Determined TDB Temps Dynamique Barycentrique- IAU Standard Ephemeris Time z.f.r.j. zero-filled, right-justified 1. General Description 1.1. Overview This Software Interface Specification (SIS) describes the Gravity Science Line of Sight Acceleration Profile Data Record pro- duced for the Magellan (MGN) and Mars Observer (MO) Projects. Both Magellan and Mars Observer are managed by the Jet Propulsion Laboratory (JPL); LOSAPDR files are created at JPL. LOSAPDR files contain results from processing of radio tracking data using program LUNRES. Splines are fitted to Doppler residual values resulting from spacecraft orbit solutions. The spline results are then interpreted as local accelerations, from which the size and location of mass anomalies within the target body can be inferred. A summary of the processing which leads to the LOSAPDR is given in Appendix A. 1.2. Scope The format and content specifications in this SIS apply to all phases of the project for which the LOSAPDR is produced. 1.3. Applicable Documents [1] MGN 630-7, Rev. D, Magellan Planetary Constants and Models, D.T. Lyons, Mission Design, Jet Propulsion Laboratory, 9 January 1991. [2] MO 642-321, Mars Observer Planetary Constants and Models, JPL D- 3444, November 1990. [3] JJPL-0006-01-00, JPL SFDU Description and Usage. Issue 5, March 7, 1988. [4] D-7669, Planetary Data System-Data Preparation Workbook, Version 2.0, Jet Propulsion Laboratory, 3 May 1991. 1.4. Subsystem Siting 1.4.1. Interface Location and Medium The LOSAPDR product is an electronic file on computer systems at the Jet Propulsion Laboratory. 1.4.2. Data Sources, Transfer Methods, and Destinations LOSAPDR files are created by program LUNRES running on a VAX/VMS computer system. Input data include Orbit Data Files containing radio tracking data from the Deep Space Network. LOSAPDR files are deliv- ered to Magellan Science Workstations or the Mars Observer Project Database over local and external networks, respectively. Although the LOSAPDR is an ASCII file, machine to machine elec- tronic transfers using the FTP utility should be carried out using FTP in binary mode. This will preserve the carriage-return line-feed record delimiters and ensure that file lengths are preserved. Note that some machines may need to modify the carriage-return line-feed structure after receiving the files and before using local utilities or application programs. 1.4.3. Generation Method and Frequency LOSAPDR files are created by program LUNRES. Each LOSAPDR con- tains data from one spacecraft orbit. LOSAPDRs are generated when the data for the appropriate orbits become available. 1.4.4. Pertinent Relationships with Other Interfaces None. 1.4.5. Labeling and Identification Names for LOSAPDR files have the form Lnnnnn.fvv where "L" indicates the LOSAPDR product type, "nnnnn" is a five-digit zero-filled, right-justified (z.f.r.j) orbit number, "f" is a one- digit fractional orbit number (set to zero for Magellan data), and "vv" is the version number of the product. Version numbers begin with 01 and are incremented by 1 for each subsequent version. Internal labeling of LOSAPDR files is accomplished with keywords and values as described in Section 4.2.1. 1.5. Assumptions and Constraints 1.5.1. Usage Constraints None. 1.5.2. Priority Phasing Constraints None. 1.5.3. Explicit and Derived Constraints None. 1.5.4. Documentation Conventions 1.5.4.1. Data Format Descriptions The LOSAPDR is a text file using ASCII character definitions. All double precision numbers (real) are represented using FORTRAN 1P1E23.16 format statements. Integers (int) are represented using FORTRAN I2 and I10 format statements. If a field is described as containing n bytes of ASCII character string data, this implies that the leftmost (lowest numbered) byte contains the first character, the next lowest byte contains the second character, and so forth. 1.5.4.2. Time Standards Within LOSAPDR files, times are expressed as a string of 23 ASCII characters YYYY-MM-DDThh:mm:ss.fff where "-", "T", ":", and "." are fixed delimiters; "YYYY" is the year "19nn" or "20nn"; "MM" is a two-digit month of year; "DD" is a two- digit day of month; "T" separates the date and time segments of the string; "hh" is hour of day; "mm" is the minutes of hour (00-59); "ss" is the seconds of minute (00-59); and "fff" is in milliseconds. The data type "TIME" is assigned to this format. When only the date is required the 10-character string YYYY-MM-DD may be substituted. The data type "DATE" is assigned to this format. Spacecraft times given in the form above are Spacecraft Event Times (SCET) in ephemeris time. Ground times, such as local processing time, indicate local time (Pacific Standard Time or Pacific Daylight Time, as appropriate). 1.5.4.3. Coordinate Systems Each LOSAPDR uses a single ad hoc inertial coordinate system, defined uniquely for that set of observations. At the reference time CALENDAR EPOCH (CEPOCH; see 4.2.1.2.1) an inertial frame is defined by the instantaneous target-fixed frame [1,2]. All positions and veloci- ties are then expressed with reference to that frame. Latitudes and longitudes, for example, are effectively specified with respect to the meridian and equator of the target-fixed frame at CEPOCH (see Appendix A). 1.5.4.4. Limits of This Document This document applies only to the LOSAPDR product. 1.5.4.5. Typographic Conventions This document has been formatted for simple electronic file transfer and display. Line lengths are limited to 72 ASCII characters, including line length delimiters. No special fonts or structures are included within the file. Constant width characters are assumed for display. 2. Interface Characteristics 2.1. Hardware Characteristics and Limitations 2.1.1. Special Equipment and Device Interfaces The LOSAPDR ASCII files are created on a VAX/VMS computer system and are delivered over networks to destination workstations and databases, as appropriate. Users of the LOSAPDR must have access to these destination facilities or to backup or archival media on which these files have been stored. 2.1.2. Special Setup Requirements None. 2.2. Volume and Size The LOSAPDR data for each spacecraft orbit consist of one file, as detailed in Section 4. File sizes vary, but a typical file contains 150 kilobytes. 2.3. Interface Medium Characteristics LOSAPDR files are electronic files. 2.4. Failure Protection, Detection, and Recovery Procedures None. 2.5. End-of-File Conventions End of file labeling complies with SFDU standards (see Section 4) and with destination workstation or database standards. 2.6. End-of-Volume Conventions End of volume labeling complies with SFDU standards (see Section 4) and with destination workstation or database standards. 3. Access 3.1. Programs Using the Interface Data contained in an LOSAPDR will be accessed by programs at the home institutions of science and other investigators. Those programs cannot be identified here. 3.2. Synchronization Considerations 3.2.1. Timing and Sequencing Considerations N/A 3.2.2. Effective Duration N/A 3.2.3. Priority Interrupts None. 3.3. Input/Output Protocols, Calling Sequences None. 4. Detailed Interface Specifications 4.1. Structure and Organization Overview The LOSAPDR is an ASCII file generated by the LUNRES Gravity Science software. It uses Standard Format Data Unit (SFDU) structures as defined in Applicable Document [3]. The overall format is illus- trated in Figure 4-1. For purposes of discussion here, the structure from the first CCSDS Header through the I-Label and its associated length field will be called "The Label"; the remainder of the file is made up of the "Header Object", the "Times Object", and the "Results Object." Examples of a complete Label and data object are given in Appendix B. |===================================================================== | | | Figure 4-1. LOSAPDR File - Block Format | | | |===================================================================== |T| |CCSD3ZF00001 |CCSDS Label| CCSDS| |-+-+-------------------------------------------+------------| | |L| |00000001 |Length Field| Header| |-+-+-------------------------------------------+------------+-------| |V|T|NJPL3KS0PDSX | K-Label | | | |-+-------------------------------------------+------------| | | |L|##mark## |Start Marker| | | |-+-------------------------------------------+------------| | | |V|PDS_VERSION_ID=PDS3 | Standard | | | | |RECORD_TYPE=FIXED_LENGTH | Keywords | | | | | ... | and |Keyword| | | |PRODUCT_RELEASE_DATE=YYYY-MM-DD | Values | and | | | |-------------------------------------------+------------| Value | | | |OBJECT=LOSAPDR_HEADER_TABLE | | SFDU | | | | ROWS=1 | | | | | | COLUMNS=42 | Data | | | | | ROW_BYTES=1030 | Object | | | | | ROW_SUFFIX_BYTES=182 | Definitions| | | | | INTERCHANGE_FORMAT=ASCII | | | | | | ... | | | |-+-+-------------------------------------------+------------+-------| |T| |CCSD$$MARKER |CCSDS Label| CCSDS | |-+-+-------------------------------------------+------------| | |L| |##mark## | End Marker | Header| |-+-+-------------------------------------------+------------+-------| |V|T|NJPL3IF00030 | I-Label | | | |-+-------------------------------------------+------------| | | |L|00000001 |Length Field| | | |-+-------------------------------------------+------------| Data | | |V| Data Fields - | | SFDU | | | | Header Object | Data | | | | | Times Object | | | | | | Results Object | | | |=|=|===========================================|============|=======| Label Components CCSDS Label "CCSD3ZF00001", the CCSDS primary SFDU label. The "F" indicates that the contents of the file are delimited by a file mark. Length Field Eight bytes, ASCII (not used in this SFDU format; set to default value "00000001" -- one file mark). Keyword and Value SFDU Contains standard keyword-value entries and object definitions for the header, times, and results data objects which follow (see Section 4.2) CCSDS Label "CCSD$$MARKER", end marker for the preceding Label-Value Object. Length Field Eight bytes ASCII "##mark##", denoting the end of The Label after 20 more bytes. I-Label "NJPL3IF00030" denotes the beginning of the data object. "0030" is the four-character identifier which is uniquely assigned to this data type by the JPL SFDU Control Authority. Length Field Eight bytes, ASCII (not used in this SFDU format; set to default value "00000001"). Data Components Header Object See Section 4.2.1.2.1 (and Section 4.2.2.1) Times Object See Section 4.2.1.2.2 (and Section 4.2.2.2) Results Object See Section 4.2.1.2.3 (and Section 4.2.2.3) 4.2. Substructure Definition and Format Substructure of the LOSAPDR includes the Keyword and Value SFDU and the Data SFDU, made up of data objects which contain the results of the analyses. 4.2.1. Keyword and Value SFDU The Keyword and Value SFDU includes two components: a section of standard keyword=value entries, and a section of object definitions. The general structure is shown in Figure 4-2. Although not shown here and in the following subsections, each line in the Standard Keyword and Value section and each line in the Object Definition sections is terminated by both the ASCII carriage return (hex 0D) and the ASCII line feed (hex 0A) characters. Further, if the total length of the Standard Keyword and Value section and the Object Definition sections is not an even number of bytes, a single ASCII blank (hex 20) is added before the final . |====================================================================| | | | Figure 4-2. Keyword-Value SFDU Block Structure | | | |====================================================================| | T | NJPL3KS0PSDX | K-Label | |---+-------------------------------------------------+--------------| | L | ##mark## | Start Marker | |---+-------------------------------------------------+--------------| | V | PDS_VERSION_ID=PDS3 | | | | RECORD_TYPE=FIXED_LENGTH | Standard | | | FILE_RECORDS=nnn | Keywords | | | RECORD_BYTES=nnn | and | | | ... | Labels | | | PRODUCT_RELEASE_DATE=YYYY-MM-DD | | | | | | | | OBJECT=LOSAPDR_HEADER_TABLE | Header | | | ... | Object | | | END_OBJECT=LOSAPDR_HEADER_TABLE | Definition | | | | | | | OBJECT=LOSAPDR_TIMES_TABLE | Times | | | ... | Object | | | END_OBJECT=LOSAPDR_TIMES_TABLE | Definition | | | | | | | OBJECT=LOSAPDR_RESULTS_TABLE | Results | | | ... | Object | | | END_OBJECT=LOSAPDR_TABLE | Definition | |===|=================================================|==============| 4.2.1.1. Keyword-Value Pairs Keywords-value pairs are shown in Figure 4-3 and are defined in the text which follows. Note that entries beginning with "^" are pointers to data objects which follow the Keyword and Value SFDU. Each line in Figure 4-3 ends with an ASCII carriage-return line-feed pair, which is not shown. |====================================================================| | | | Figure 4-3. Keyword-Value Pairs | | | |====================================================================| | PDS_VERSION_ID=PDS3 | | | FILE_NAME="Lnnnnn.fvv" | | | RECORD_TYPE=FIXED_LENGTH | | | RECORD_BYTES=202 | | | FILE_RECORDS=nnn | | | LABEL_RECORDS=nnn | | | ^LOSAPDR_HEADER_TABLE=nnn | | | ^LOSAPDR_TIMES_TABLE=nnn | | | ^LOSAPDR_RESULTS_TABLE=nnn | | | SPACECRAFT_NAME="ccccccc" | | | TARGET_NAME="cccccccc" | Standard | | INSTRUMENT_NAME="RADIO SCIENCE SUBSYSTEM" | Keywords | | DATA_SET_ID="ccccccccccccccc" | and | | PRODUCT_ID="RS-Lnnnnn.fvv" | Values | | DESCRIPTION="ccccc" | | | SOFTWARE_NAME="LUNRES;n.mm" | | | START_TIME=YYYY-MM-DDThh:mm:ss.fff | | | STOP_TIME=YYYY-MM-DDThh:mm:ss.fff | | | SPACECRAFT_CLOCK_START_COUNT="N/A" | | | SPACECRAFT_CLOCK_STOP_COUNT="N/A" | | | PRODUCER_ID="MGN GRAVSCI TEAM" | | | PRODUCT_CREATION_TIME=YYYY-MM-DDThh:mm:ss.fff | | | PRODUCT_RELEASE_DATE=YYYY-MM-DD | | |=======================================================|============| Each definition below includes a Mars Observer (MO) "policy value," which indicates handling of the keyword by the MO data base. Handling is as follows: |====================================================================| | | | Table 4-1. MO PDB Policy Values | | | |====================================================================| | Policy Value | MO Handling | |--------------+-----------------------------------------------------| | A |Keyword is required, but value is not cataloged | |--------------+-----------------------------------------------------| | B |Keyword is required; value must be valid and will be | | |cataloged. | |--------------+-----------------------------------------------------| | C |Keyword is optional; if present, the value will be | | |cataloged. | |--------------+-----------------------------------------------------| | D |Keyword is optional; value is ignored. | |==============|=====================================================| PDS_VERSION_ID= The version of the Planetary Data System for which these data have been prepared (by agree- ment among the Magellan Project, the Mars Observer Project, and PDS, PDS_VERSION_ID = PDS3). MO policy value A. FILE_NAME= A character string of the form "Lnnnnn.fvv" where the components are defined in Section 1.4.5. MO policy value C. RECORD_TYPE= The record format for the file (set to "FIXED_LENGTH"). MO policy value A. RECORD_BYTES= An integer number nnn giving the number of bytes per logical record throughout the file. The product of the number of records (FILE_RECORDS) and the number of bytes per record (RECORD_BYTES) is the size of the file in bytes. For the LOSAPDR, set to 202, which is the intrinsic length of records in the Results Object. MO policy value A. FILE_RECORDS= An integer number nnn giving the total number of records in the file. The multiplicative product of the number of records (FILE_RECORDS) and the number of bytes per record (RECORD_BYTES) is the size of the file in bytes. MO policy value A. LABEL_RECORDS= An integer number nnn giving the number of records required to specify The Label. MO policy value A. ^LOSAPDR_HEADER_TABLE= Pointer to the start of the LOSAPDR Header Object. An integer nnn giving the starting record number for the Header Object in this file. Record numbering within the file starts from record 1, incrementing once for each subsequent record of length RECORD_BYTES. MO has no policy values for pointers; pointers are ignored. ^LOSAPDR_TIMES_TABLE= Pointer to the start of the LOSAPDR Times Object. An integer nnn giving the starting record number for the (spline interval) Times Object in this file. Record numbering within the file starts from record 1, incrementing once for each subsequent record of length RECORD_BYTES. MO has no policy values for pointers; pointers are ignored. ^LOSAPDR_RESULTS_TABLE= Pointer to the start of the LOSAPDR Results Object. An integer nnn giving the starting record number for the Results Object in this file. Record numbering within the file starts from record 1, incrementing once for each subsequent record of length RECORD_BYTES. MO has no policy values for pointers; pointers are ignored. SPACECRAFT_NAME= A character string which identifies the spacecraft. For Magellan, the character string "MAGELLAN"; for Mars Observer, the character string "MARS OBSERVER". MO policy value A. TARGET_NAME= A character string which identifies the target body. For Magellan, the character string "VENUS"; for Mars Observer, the character string "MARS". MO policy value B. INSTRUMENT_NAME= The character string "RADIO SCIENCE SUBSYSTEM". MO policy value B. DATA_SET_ID= The data set identification as defined by the Planetary Data System [4]. For Magellan, the character string "MGN-V-RSS-5-LOSAPDR-L2- Vn.m"; for Mars Observer, the character string "MO-M-RSS-5-LOSAPDR-L2-Vn.m", where Vn.m denotes version number of the data set. MO policy value B. PRODUCT_ID= A character string of the form "RS-Lnnnnn.fvv" where "RS-" is prepended to the FILE_NAME and the FILE_NAME components are defined in Section 1.4.5. MO policy value B. DESCRIPTION= A character string "cccc" containing a brief description of the data product. MO policy value A. SOFTWARE_NAME= The character string "LUNRES;n.mm" where "LUNRES" is the generating program and "n.mm" denotes the version of that program used to create the data file. MO policy value A. START_TIME= A character string indicating the SCET of the first tracking data point, in the format YYYY- MM-DDThh:mm:ss.fff (see Section 1.5.4.2) MO policy value B. STOP_TIME= A character string indicating the SCET of the last tracking data point, in the format YYYY- MM-DDThh:mm:ss.fff (see Section 1.5.4.2) MO policy value B. SPACECRAFT_CLOCK_START_COUNT= The character string "N/A" MO policy value D. SPACECRAFT_CLOCK_STOP_COUNT= The character string "N/A" MO policy value D. PRODUCER_ID= A character string which identifies the group producing the file. For Magellan, the character string "MGN GRAVSCI TEAM"; for Mars Observer, the character string "MO RS TEAM". MO policy value B. PRODUCT_CREATION_TIME= A character string indicating the date and time at which the file was created [in the format YYYY-MM-DDThh:mm:ss.fff (see Section 1.5.4.2)] MO policy value B. PRODUCT_RELEASE_DATE= A character string indicating the date at which the file is to be released to the Planetary Data System [in the format YYYY-MM- DD (see Section 1.5.4.2)] MO policy value B. 4.2.1.2. Object Definitions Object Definitions are series of statement groups of the form OBJECT=OBJECT_NAME ATTRIBUTE_1=ATTRIBUTE_1_VALUE ATTRIBUTE_2=ATTRIBUTE_2_VALUE ... ATTRIBUTE_N=ATTRIBUTE_N_VALUE END_OBJECT=OBJECT_NAME where each indented line specifies an attribute of the object (its size, line length, etc.). Attributes can themselves be object defini- tions, allowing nesting within the definition statement. For example, a primary Object Definition may specify a table; nested Object Definitions can be used to specify each of the columns within the table. Data Objects within the LOSAPDR are the Header Object, the Times Object, and the Results Object. Each contains data in tabular form. Each Object Definition first defines the table itself; nested subsidiary Object Definitions are used to define each of the table columns. 4.2.1.2.1. Header Object Definition The Header Object is a single-row multi-column table containing information on initial values, control parameters, and simple calcula- tions required by the generating program LUNRES. The Header Object is completely defined by the Object Definition below; the structure of the Header Object is also given in Section 4.2.2.1. Although not shown here, each line in the definition below is padded on the right with ASCII blanks to a length of 200 bytes and then terminated by both the ASCII carriage return (hex 0D) and the ASCII line feed (hex 0A) characters. Column entries in the table are separated by ASCII commas (hex 2D). The total length of the header table must be an integral multi- ple of 202 bytes (the record length for the data blocks). A pad of 180 ASCII blank characters fills out the last record. An ASCII carriage return (hex 0D) and an ASCII line feed (hex 0A) follow the pad. The total length of the header table is thus 1212 characters -- exactly six times the value of RECORD_BYTES. OBJECT = LOSAPDR_HEADER_TABLE ROWS = 1 COLUMNS = 42 ROW_BYTES = 1030 ROW_SUFFIX_BYTES = 182 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The LOSAPDR header includes input data and summary results from initial ODP and LUNRES calculations. It is a single-row table with 42 columns, two of which have three elements each. The data are represented as ASCII characters; entries are delimited by commas. The total of the data plus delimiters is 1030 characters, followed by 180 padding characters and a carriage-return line-feed pair. The row thus has 1212 characters, which is exactly six times the value of RECORD_BYTES." OBJECT = COLUMN NAME = "PLANETARY RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "The assumed radius of the spherical planet (program mnemonic RADIUS)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "GM" DATA_TYPE = ASCII_REAL START_BYTE = 25 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETERS CUBED PER SECOND SQUARED" DESCRIPTION = "The assumed gravitational constant for the planet." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CALENDAR EPOCH" DATA_TYPE = TIME START_BYTE = 49 BYTES = 23 UNIT = "N/A" DESCRIPTION = "The calendar epoch in ephemeris time of the initial state vector at the spacecraft. The initial state vector is given by SPACECRAFT POSITION and SPACECRAFT VELOCITY below. (program mnemonic CEPOCH)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "JULIAN EPHEMERIS DAYS" DATA_TYPE = ASCII_REAL START_BYTE = 73 BYTES = 23 FORMAT = "E23.16" UNIT = "DAY" DESCRIPTION = "The Julian date corresponding to CEPOCH (ephemeris time at the space- craft) (program mnemonic JED)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT POSITION" ITEMS = 3 ITEM_BYTES = 23 ITEM_OFFSET = 24 DATA_TYPE = ASCII_REAL START_BYTE = 97 BYTES = 71 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "The spacecraft position vector at CEPOCH, calculated in program ODP (program mnemonics XS, YS, and ZS)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT VELOCITY" ITEMS = 3 ITEM_BYTES = 23 ITEM_OFFSET = 24 DATA_TYPE = ASCII_REAL START_BYTE = 169 BYTES = 71 FORMAT = "E23.16" UNIT = "KILOMETER PER SECOND" DESCRIPTION = "The spacecraft velocity vector at CEPOCH, calculated in program ODP (program mnemonics DXS, DYS, and DZS)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 241 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric longitude of the spacecraft corresponding to SPACECRAFT POSITION at CEPOCH (program mnemonic LONEP)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT HOUR ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 265 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "The hour angle of the spacecraft corresponding to SPACECRAFT POSITION at CEPOCH (program mnemonic HANG)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DOBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 289 BYTES = 2 FORMAT = "I2" UNIT = "N/A" DESCRIPTION = "Flag for constant (-1) or variable (+1) time spacing in spline fits. If DOBKS=+1, the time intervals in BKTIMX will be unequal." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "RECORD SPACING" DATA_TYPE = ASCII_REAL START_BYTE = 292 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Time spacing of the output records in the RESULTS_TABLE (program mnemonic DTACC). Large values may mean that spacing defaults to the spacing of the data points (no interpolated data)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MINBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 316 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Minimum number of data points in each spline interval (used only if DOBKS=+1)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MAXBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 327 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Maximum number of data points in each spline interval (used only if DOBKS=+1)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "BAND" DATA_TYPE = ASCII_REAL START_BYTE = 338 BYTES = 23 FORMAT = "E23.16" UNIT = "MILLIMETER PER SECOND" DESCRIPTION = "Conversion factor from Doppler to acceleration. Nominally 0.2955 for X-band data and 1.0833 for S-band data." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TADD" DATA_TYPE = ASCII_REAL START_BYTE = 362 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Time from CEPOCH to first data point (at the spacecraft)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TFIT" DATA_TYPE = ASCII_REAL START_BYTE = 386 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Time from TADD to last data point (at the spacecraft)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DFIT" DATA_TYPE = ASCII_REAL START_BYTE = 410 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Length of each spline interval (used only when DOBKS=-1)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REJECT" DATA_TYPE = ASCII_REAL START_BYTE = 434 BYTES = 23 FORMAT = "E23.16" UNIT = "HERTZ" DESCRIPTION = "Threshold for rejection of bad data points." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "EARTH LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 458 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric longitude of Earth at CEPOCH (program mnemonic LNE)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "EARTH LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 482 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric north latitude of Earth at CEPOCH (program mnemonic LTE)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TRANSA" DATA_TYPE = ASCII_REAL START_BYTE = 506 BYTES = 23 FORMAT = "E23.16" UNIT = "SECOND" DESCRIPTION = "One-way downlink light- time for a photon leaving the spacecraft at CEPOCH." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TRANSB" DATA_TYPE = ASCII_REAL START_BYTE = 530 BYTES = 23 FORMAT = "E23.16" UNIT = "SECOND PER SECOND" DESCRIPTION = "Rate of change of TRANSA" END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DUTSEC" DATA_TYPE = ASCII_REAL START_BYTE = 554 BYTES = 23 FORMAT = "E23.16" UNIT = "SECOND" DESCRIPTION = "Difference between ephemeris time (ET) and universal time (UT)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFEP" DATA_TYPE = TIME START_BYTE = 578 BYTES = 23 UNIT = "N/A" DESCRIPTION = "Reference epoch for TRANSA and TRANSB at the spacecraft (same time system, and often the same value, as CEPOCH)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL SEMIMAJOR AXIS" DATA_TYPE = ASCII_REAL START_BYTE = 602 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Semi-major axis of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic SMA)" END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL ECCENTRICITY" DATA_TYPE = ASCII_REAL START_BYTE = 626 BYTES = 23 FORMAT = "E23.16" UNIT = "DIMENSIONLESS" DESCRIPTION = "Eccentricity of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic ECC)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL INCLINATION" DATA_TYPE = ASCII_REAL START_BYTE = 650 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Inclination of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic INC)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ASCENDING NODE LONGITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 674 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Ascending node of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic NODE)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS ARGUMENT ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 698 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Argument of periapsis for spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic ARG)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TRUE ANOMALY ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 722 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "True anomaly of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic F)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MEAN ANOMALY ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 746 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Mean anomaly of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic M)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ECCENTRIC ANOMALY ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 770 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Eccentric anomaly of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic E)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL PERIOD" DATA_TYPE = ASCII_REAL START_BYTE = 794 BYTES = 23 FORMAT = "E23.16" UNIT = "HOUR" DESCRIPTION = "Period of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic P)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 818 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric north latitude at periapsis for spacecraft orbit (program mnemonic LATPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 842 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric longitude of periapsis for spacecraft orbit (program mnemonic LONPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 866 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft distance from target center of mass at periapsis (program mnemonic RPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS VELOCITY" DATA_TYPE = ASCII_REAL START_BYTE = 890 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER PER SECOND" DESCRIPTION = "Spacecraft velocity at periapsis (program mnemonic VPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS ALTITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 914 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft altitude over reference surface at periapsis (program mnemonic APER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "APOAPSIS RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 938 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft distance from target center of mass at apoapsis (program mnemonic RAPO)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "APOAPSIS VELOCITY" DATA_TYPE = ASCII_REAL START_BYTE = 962 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER PER SECOND" DESCRIPTION = "Spacecraft velocity at apoapsis (program mnemonic VAPO)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "APOAPSIS ALTITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 986 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft altitude over reference surface at apoapsis (program mnemonic AAPO)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 1010 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Number of times in the Times Table defining spline intervals." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NPOINT" DATA_TYPE = ASCII_INTEGER START_BYTE = 1021 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Number of data points used to make this file." END_OBJECT = COLUMN END_OBJECT = LOSAPDR_HEADER_TABLE 4.2.1.2.2. Times Object Definition The Times Object is a table containing exact times bounding spline intervals. Each row in the table has RECORD_BYTES=202 bytes; the number of rows is given by NBKS (see Section 4.2.1.2.1) and may be variable. The symbol "*" denotes the value of NBKS, which must be provided before the Times Object Definition is used. Although not shown here, each line in the Times Object Definition is terminated by both the ASCII carriage return (hex 0D) and the ASCII line feed (hex 0A) characters. The table is a single column containing 23-character ASCII representations of double precision numbers. It is described completely by the Times Object Definition below; the structure is also given in Section 4.2.2.2. Each row in the table is padded with 177 ASCII blanks followed by an ASCII carriage return (hex 0D) and an ASCII line feed (hex 0A) -- a total of RECORD_BYTES=202 characters. OBJECT = LOSAPDR_TIMES_TABLE ROWS = * COLUMNS = 1 ROW_BYTES = 23 ROW_SUFFIX_BYTES = 179 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The LOSAPDR times table contains exact times bounding each spline interval. Each row contains one 23-digit number, 177 spaces, and a carriage-return line-feed pair." OBJECT = COLUMN NAME = "SPLINE BREAK TIMES" DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "The exact times of spline interval boundaries measured from midnight at the spacecraft (program mnemonic BKTIMX)." END_OBJECT = COLUMN END_OBJECT = LOSAPDR_TIMES_TABLE 4.2.1.2.3. Results Object Definition The LOSAPDR Data Object is a table containing results from spline fits to Doppler tracking residuals. It is completely described by the Results Object Definition below. Although not shown here, each line in the Results Object Definition is terminated by both the ASCII carriage return (hex 0D) and the ASCII line feed (hex 0A) characters. The table has eleven columns; its length is variable -- that is, it has a variable number of rows. The symbol "*" below denotes the number of rows, which must be provided before the Results Object Definition is used. Column entries are separated by ASCII commas (hex 2D). OBJECT = LOSAPDR_RESULTS_TABLE ROWS = * COLUMNS = 11 ROW_BYTES = 202 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The LOSAPDR Results Table contains the results from spline fits to Doppler tracking residuals. Each row in the table contains times, Doppler residuals, spacecraft position information, residuals to spline fits, and inferred spacecraft acceleration with respect to the nominal Keplerian orbit. Each row has length 202 bytes; the first 200 are column data delimited by commas; the last two are a carriage- return line-feed pair." OBJECT = COLUMN NAME = "HH" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 2 FORMAT = "I2.2" UNIT = "HOUR" DESCRIPTION = "The hour of a Doppler residual data point at the spacecraft." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MM" DATA_TYPE = ASCII_INTEGER START_BYTE = 4 BYTES = 2 FORMAT = "I2.2" UNIT = "MINUTE" DESCRIPTION = "The minute of a Doppler residual data point at the spacecraft." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SS" DATA_TYPE = ASCII_INTEGER START_BYTE = 7 BYTES = 2 FORMAT = "I2.2" UNIT = "SECOND" DESCRIPTION = "The whole seconds of a Doppler residual data point at the spacecraft. Note that there are generally fractional seconds; for full time accuracy use OFFSET TIME." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "OFFSET TIME" DATA_TYPE = ASCII_REAL START_BYTE = 10 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Offset from CEPOCH to the time of the Doppler residual data point or inter- polation (program mnemonic DMIN)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DOPPLER RESIDUAL" DATA_TYPE = ASCII_REAL START_BYTE = 34 BYTES = 23 FORMAT = "E23.16" UNIT = "HERTZ" DESCRIPTION = "Doppler residual from input data (program mnemonic DATA_RESID)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT ALTITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 58 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft altitude over reference surface (program mnemonic SC_ALT)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 82 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Spacecraft planetocentric north latitude (program mnemonic SC_LAT)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 106 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Spacecraft planetocentric longitude (program mnemonic SC_LON)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "FIT RESIDUAL" DATA_TYPE = ASCII_REAL START_BYTE = 130 BYTES = 23 FORMAT = "E23.16" UNIT = "HERTZ" DESCRIPTION = "Doppler residual from fitted spline at HHMMSS (program mnemonic FIT_RESID)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ACCELERATION" DATA_TYPE = ASCII_REAL START_BYTE = 154 BYTES = 23 FORMAT = "E23.16" UNIT = "MILLIMETER PER SECOND PER SECOND" DESCRIPTION = "Acceleration from fitted Doppler residual (program mnemonic ACCEL)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ACCELERATION UNCERTAINTY" DATA_TYPE = ASCII_REAL START_BYTE = 178 BYTES = 23 FORMAT = "E23.16" UNIT = "MILLIMETER PER SECOND PER SECOND" DESCRIPTION = "Uncertainty in the acceleration from the fitted Doppler residual." END_OBJECT = COLUMN END_OBJECT = LOSAPDR_RESULTS_TABLE 4.2.2. Data Objects The three data objects defined in Section 4.2.1.2 are shown in table form in the next three subsections. 4.2.2.1. Header Object The Header Object is shown in Table 4-2. For definitions of entries, see Section 4.2.1.2.1. Entries in the Header Object are separated by ASCII commas (hex 2D). The 180 characters in the Header Object immediately following the data are ASCII space characters. The final two characters are an ASCII carriage return (hex 0D) and an ASCII line feed (hex 0A), bringing the total object size to exactly six times RECORD_BYTES=202, or 1212 bytes (Section 4.2.1.1). |====================================================================| | | | Table 4-2. LOSAPDR Header Object | | | |====================================================================| |Offset|Length|Type|Mnemonic| Description | |------+------+----+--------+----------------------------------------| | +0 | 23 |real| RADIUS |Assumed spherical radius of target body | | | | | | (km)| |------+------+----+--------+----------------------------------------| | 24 | 23 |real| GM |Gravitational constant of target | | | | | | (km**3/sec**2)| |------+------+----+--------+----------------------------------------| | 48 | 23 |time| CEPOCH |Epoch for initial spacecraft state | | | | | | vector| |------+------+----+--------+----------------------------------------| | 72 | 23 |real| JED |Julian date corresponding to CEPOCH | |------+------+----+--------+----------------------------------------| | 96 | 3*23 |real| P[3] |Spacecraft position at CEPOCH (km) | |------+------+----+--------+----------------------------------------| | 168 | 3*23 |real| V[3] |Spacecraft velocity at CEPOCH (km/sec) | |------+------+----+--------+----------------------------------------| | 240 | 23 |real| LONEP |Spacecraft longitude at CEPOCH (deg) | |------+------+----+--------+----------------------------------------| | 264 | 23 |real| HANG |Spacecraft hour angle at CEPOCH (deg) | |------+------+----+--------+----------------------------------------| | 288 | 2 |int | DOBKS |Flag for spline interval spacing | |------+------+----+--------+----------------------------------------| | 291 | 23 |real| DTACC |Time spacing in output file (minutes) | |------+------+----+--------+----------------------------------------| | 315 | 10 |int | MINBKS |Min number of points, spline intervals | |------+------+----+--------+----------------------------------------| | 326 | 10 |int | MAXBKS |Max number of points, spline intervals | |------+------+----+--------+----------------------------------------| | 337 | 23 |real| BAND |Doppler to acceleration scale factor | | | | | | (mm/sec)| |------+------+----+--------+----------------------------------------| | 361 | 23 |real| TADD |Time from CEPOCH to first data point | | | | | | (min)| |------+------+----+--------+----------------------------------------| | 385 | 23 |real| TFIT |Time from CEPOCH to last data point | | | | | | (min)| |------+------+----+--------+----------------------------------------| | 409 | 23 |real| DFIT |Length of spline interval (minutes) | |------+------+----+--------+----------------------------------------| | 433 | 23 |real| REJECT |Rejection threshold for Doppler values | | | | | | (Hz)| |------+------+----+--------+----------------------------------------| | 457 | 23 |real| LNE |Longitude of Earth from target (deg) | |------+------+----+--------+----------------------------------------| | 481 | 23 |real| LTE |Latitude of Earth from target (deg N) | |------+------+----+--------+----------------------------------------| | 505 | 23 |real| TRANSA |One-way light time at CEPOCH (secs) | |------+------+----+--------+----------------------------------------| | 529 | 23 |real| TRANSB |Rate of change of TRANSA (sec/sec) | |------+------+----+--------+----------------------------------------| | 553 | 23 |real| DUTSEC |Ephemeris Time minus UTC (secs) | |------+------+----+--------+----------------------------------------| | 577 | 23 |time| REFEP |Reference time for TRANSA, TRANSB | |------+------+----+--------+----------------------------------------| | 601 | 23 |real| SMA |Semi-major axis of spacecraft orbit (km)| |------+------+----+--------+----------------------------------------| | 625 | 23 |real| ECC |Eccentricity of spacecraft orbit | |------+------+----+--------+----------------------------------------| | 649 | 23 |real| INC |Inclination of spacecraft orbit (deg) | |------+------+----+--------+----------------------------------------| | 673 | 23 |real| NODE |Ascending node of spacecraft orbit (deg)| |------+------+----+--------+----------------------------------------| | 697 | 23 |real| ARG |Argument of periapsis for spacecraft | | | | | | orbit (deg)| |------+------+----+--------+----------------------------------------| | 721 | 23 |real| F |True anomaly of spacecraft orbit (deg) | |------+------+----+--------+----------------------------------------| | 745 | 23 |real| M |Mean anomaly of spacecraft orbit (deg) | |------+------+----+--------+----------------------------------------| | 769 | 23 |real| E |Eccentric anomaly of spacecraft orbit | | | | | | (deg)| |------+------+----+--------+----------------------------------------| | 793 | 23 |real| P |Period of spacecraft orbit (hours) | |------+------+----+--------+----------------------------------------| | 817 | 23 |real| LATPER |Latitude of periapsis from target | | | | | | (deg N)| |------+------+----+--------+----------------------------------------| | 841 | 23 |real| LONPER |Longitude of periapsis from target (deg)| | | | | | | |------+------+----+--------+----------------------------------------| | 865 | 23 |real| RPER |Spacecraft distance from C/M at | | | | | | periapsis (km)| |------+------+----+--------+----------------------------------------| | 889 | 23 |real| VPER |Spacecraft velocity at periapsis | | | | | | (km/sec)| |------+------+----+--------+----------------------------------------| | 913 | 23 |real| APER |Altitude of S/C over ref surf at | | | | | | periapsis (km)| |------+------+----+--------+----------------------------------------| | 937 | 23 |real| RAPO |Spacecraft distance from C/M at apoapsis| | | | | | (km)| |------+------+----+--------+----------------------------------------| | 961 | 23 |real| VAPO |Spacecraft velocity at apoapsis (km/sec)| |------+------+----+--------+----------------------------------------| | 985 | 23 |real| AAPO |Altitude of S/C over ref surf at | | | | | | apoapsis (km)| |------+------+----+--------+----------------------------------------| | 1009 | 10 |int | NBKS |Number of spline intervals | |------+------+----+--------+----------------------------------------| | 1020 | 10 |int | NPOINT |Number of time points used by spline | |------+------+----+--------+----------------------------------------| | 1030 | 180 |char| | blanks | |------+------+----+--------+----------------------------------------| | 1210 | 1 |char| | ASCII carriage return | |------+------+----+--------+----------------------------------------| | 1211 | 1 |char| | ASCII line feed | |------+------+----+--------+----------------------------------------| |+1212 | | | | | |======|======|====|========|========================================| 4.2.2.2 Times Object The Times Table is made from two or more Times Blocks; the structure of a Times Block is shown in Table 4-3. For definitions of entries, see Section 4.2.1.2.2. Note that each block represents a single element in the array of spline interval times, the number of which is given by NBKS which is an entry in the Header Object. Each block is padded to bring its total length to RECORD_BYTES=202 characters; the character used to pad is the ASCII space except that the last two must be a carriage-return and a line-feed. |====================================================================| | | | Table 4-3. LOSAPDR Times Block | | | |====================================================================| |Offset|Length|Type| Name | Description | |------+------+----+--------+----------------------------------------| | +0 | 23 |real| BKTIMX |Spline interval time | |------+------+----+--------+----------------------------------------| | 24 | 177 | | | blanks | |------+------+----+--------+----------------------------------------| | 200 | 1 |char| | ASCII carriage-return | |------+------+----+--------+----------------------------------------| | 201 | 1 |char| | ASCII line-feed | |------+------+----+--------+----------------------------------------| | +202 | | | | | |======|======|====|========|========================================| 4.2.2.3 Results Object The Results Object is comprised of one or more Results Blocks, the structure of which is shown in Table 4-4. For definitions of entries, see Section 4.2.1.2.3. Each Results Block is usually repeated many times. Columns within the Results Block are delimited by commas; each Results Block is terminated by an ASCII carriage- return, followed by an ASCII line-feed. |====================================================================| | | | Table 4-4. LOSAPDR Results Block | | | |====================================================================| |Offset|Length|Type| Name | Description | |------+------+----+----------+--------------------------------------| | +0 | 2 |int | HH |Data point time (hours) | |------+------+----+----------+--------------------------------------| | 3 | 2 |int | MM |Data point time (minutes) | |------+------+----+----------+--------------------------------------| | 6 | 2 |int | SS |Data point time (seconds) | |------+------+----+----------+--------------------------------------| | 9 | 23 |real| DMIN |Offset from CEPOCH (minutes) | |------+------+----+----------+--------------------------------------| | 33 | 23 |real|DATA_RESID|Doppler residual from data (Hz); | |------+------+----+----------+--------------------------------------| | 57 | 23 |real| SC_ALT |Spacecraft altitude over reference | | | | | | surface (km)| |------+------+----+----------+--------------------------------------| | 81 | 23 |real| SC_LAT |Spacecraft latitude (deg N) | |------+------+----+----------+--------------------------------------| | 105 | 23 |real| SC_LON |Spacecraft longitude (deg) | |------+------+----+----------+--------------------------------------| | 129 | 23 |real| FIT_RESID|Doppler residual from fit (Hz) | |------+------+----+----------+--------------------------------------| | 153 | 23 |real| ACCEL |Acceleration (mm/sec/sec) | |------+------+----+----------+--------------------------------------| | 177 | 23 |real| ACCEL-UNC|Acceleration uncertainty (mm/sec/sec) | |------+------+----+----------+--------------------------------------| | 200 | 1 |char| | ASCII carriage-return | |------+------+----+----------+--------------------------------------| | 201 | 1 |char| | ASCII line-feed | |------+------+----+----------+--------------------------------------| | +202 | | | | | |======|======|====|==========|======================================| Appendix A Processing Summary Tracking data (Orbit Data Files) are used to obtain an orbit solution for the spacecraft expressed in Keplerian elements and derived quantities |====================================================================| | | | Table A-1 Definition of Terms for Processing | | | |====================================================================| | LISTED QUANTITY | PROGRAM | DESCRIPTION | | | MNEMONIC| | |-------------------------+---------+--------------------------------| |ORBITAL SEMIMAJOR AXIS | SMA |Semi-major axis of spacecraft | | | | orbit (km)| |-------------------------+---------+--------------------------------| |ORBITAL ECCENTRICITY | ECC |Eccentricity of spacecraft orbit| |-------------------------+---------+--------------------------------| |ORBITAL INCLINATION | INC |Inclination of spacecraft orbit | | | | (degrees)| |-------------------------+---------+--------------------------------| |ASCENDING NODE LONGITUDE | NODE |Ascending node of spacecraft | | | | orbit (degrees)| |-------------------------+---------+--------------------------------| |PERIAPSIS ARGUMENT ANGLE | ARG |Argument of periapsis for | | | | spacecraft orbit (deg)| |-------------------------+---------+--------------------------------| |TRUE ANOMALY ANGLE | F |True anomaly of spacecraft orbit| | | | (deg)| |-------------------------+---------+--------------------------------| |MEAN ANOMALY ANGLE | M |Mean anomaly of spacecraft orbit| | | | (deg)| |-------------------------+---------+--------------------------------| |ECCENTRIC ANOMALY ANGLE | E |Eccentric anomaly of spacecraft | | | | orbit (deg)| |-------------------------+---------+--------------------------------| |ORBITAL PERIOD | P |Period of spacecraft orbit (hrs)| |-------------------------+---------+--------------------------------| |PERIAPSIS LATITUDE | LATPER |Latitude of periapsis from | | | | target (deg N)| |-------------------------+---------+--------------------------------| |PERIAPSIS LONGITUDE | LONPER |Longitude of periapsis from | | | | target (deg)| |-------------------------+---------+--------------------------------| |PERIAPSIS RADIUS | RPER |Spacecraft distance from C/M at | | | | periapsis (km)| |-------------------------+---------+--------------------------------| |PERIAPSIS VELOCITY | VPER |Spacecraft velocity at periapsis| | | | (km/sec)| |-------------------------+---------+--------------------------------| |PERIAPSIS ALTITUDE | APER |Altitude of S/C over ref surf at| | | | periapsis (km)| |-------------------------+---------+--------------------------------| |APOAPSIS RADIUS | RAPO |Spacecraft distance from C/M at | | | | apoapsis (km)| |-------------------------+---------+--------------------------------| |APOAPSIS VELOCITY | VAPO |Spacecraft velocity at apoapsis | | | | (km/sec)| |-------------------------+---------+--------------------------------| |APOAPSIS ALTITUDE | AAPO |Altitude of S/C over ref surf at| | | | apoapsis (km)| |=========================|=========|================================| TADD . . \ . . . . / . P, V, CEPOCH . . ooooooo target . . ooooooooooo / . . ooooooooooooo . . ooooooooooooo ^ . ooooooooooooo . . ooooooooooo . . ooooooo . . . . . . . / . TFIT . . Figure A-1. Schematic of spacecraft and target system, illustrating relationships among CEPOCH, TADD, and TFIT. Dots indicate orbit; spacecraft moves counterclockwise from CEPOCH through the fitted part of the orbit from CEPOCH+TADD to CEPOCH+TADD+TFIT. ---------- Doppler residuals DATA_RESID with respect to the solution are then calculated, and splines are fitted to the residuals. The fitted curves, after differentiation, can be interpreted as spacecraft accelerations relative to a simple Keplerian orbit about a homogeneous spherical target characterized by radius RADIUS and gravitational constant GM. The accelerations, in turn, may be used to infer anomalous mass concentrations within the otherwise homogeneous target. The initial state for the calculation is position P and velocity V at time CEPOCH. The position and velocity vectors are given in an inertial coordinate system which is identical to the target-fixed (rotating) frame at CEPOCH (and only at CEPOCH). CEPOCH is in spacecraft ephemeris time (E.T.). Time from the reference CEPOCH to the first tracking data point is TADD (minutes); time from the first data point to the last data point is TFIT (minutes). | | D | O | X P | X P | L | X E | X spline R | / | X / R | \ E | X X-X X S | \ / \ X I | X-X X D | X X X U | X A | L | S | BKTIMX |<--DFIT-->| | \ | (1) (2) (3) (NBKS+1) +----+-------+------+-------+----------+---------/ /---+---+------ / / / CEPOCH CEPOCH+TADD CEPOCH+TADD+TFIT TIME Figure A-2. Spline fit and times used in defining it. Spline fit interval boundaries BKTIMX(n) are indicated above the horizontal axis; the number of intervals is NBKS. Interval length DFIT is specified only when it is a constant. ---------- The spline is a cubic polynomial having continuous second derivatives at the end points, producing smooth accelerations when differentiated. The window, or interval, for which each polynomial applies has length DFIT (approximately 1-2 minutes). When DOBKS=-1, the windows have constant size throughout the entire profile. When DOBKS is positive the window size can vary -- as a function of spacecraft altitude, for example. The actual window or spline boundaries are tabulated in BKTIMX in units of minutes from midnight. The time TDSS (in UTC) at which a tracking data point is received at a ground station is: TDSS = TSC + TRANSA - DUTSEC where TSC = ephemeris time at the spacecraft (HH:MM:SS; see Results Table) TRANSA = one way light time in seconds DUTSEC = accumulated leap seconds (difference between ET and UTC) Appendix B - Example Label and Data Object B.1 Example Label The label which follows has been designed for the Magellan Line of Sight Acceleration Data Record. In the next section, an edited representative data object is shown CCSD3ZF0000100000001NJPL3KS0PDSX##mark## /* File information */ PDS_VERSION_ID = "PDS3" FILE_NAME = "L04830.001" RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 202 FILE_RECORDS = 172 LABEL_RECORDS = 150 ^LOSAPDR_HEADER_TABLE = 151 ^LOSAPDR_TIMES_TABLE = 157 ^LOSAPDR_RESULTS_TABLE = 162 SPACECRAFT_NAME = "MAGELLAN" TARGET_NAME = "VENUS" INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM" DATA_SET_ID = "MGN-V-RSS-5-LOSAPDR-L2-V1.0" PRODUCT_ID = "RS-L04830.001" DESCRIPTION = "The LOSAPDR (Line of Sight Acceleration Profile Data Record) is a set of three tables represented in ASCII character format which summarize the analysis of radio tracking data of orbiting planetary spacecraft (specifically, Magellan or Mars Observer). The first table identifies input parameters and conditions; the second table gives times between which spline fits to data points are valid; and the third table gives times, Doppler residuals, spline fit residuals, and inferred values of spacecraft acceleration with respect to the nominal Keplerian orbit. The LOSAPDR is produced at the Jet Propulsion Laboratory under the supervision of W.L. Sjogren." SOFTWARE_NAME = "LUNRES;7.89" START_TIME = 1992-12-19T04:56:56.332 STOP_TIME = 1992-12-19T05:14:19.554 SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCER_ID = "MGN GRAVSCI TEAM" PRODUCT_CREATION_TIME = 1993-01-15T12:43:55.129 PRODUCT_RELEASE_DATE = 1993-05-15 /* Structure Objects */ OBJECT = LOSAPDR_HEADER_TABLE ROWS = 1 COLUMNS = 42 ROW_BYTES = 1030 ROW_SUFFIX_BYTES = 182 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The LOSAPDR header includes input data and summary results from initial ODP and LUNRES calculations. It is a single-row table with 42 columns, two of which have three elements each. The data are represented as ASCII characters; entries are delimited by commas. The total of the data plus delimiters is 1030 characters, followed by 180 padding characters and a carriage-return line-feed pair. The row thus has 1212 characters, which is exactly six times the value of RECORD_BYTES." OBJECT = COLUMN NAME = "PLANETARY RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "The assumed radius of the spherical planet (program mnemonic RADIUS)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "GM" DATA_TYPE = ASCII_REAL START_BYTE = 25 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETERS CUBED PER SECOND SQUARED" DESCRIPTION = "The assumed gravitational constant for the planet." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CALENDAR EPOCH" DATA_TYPE = TIME START_BYTE = 49 BYTES = 23 UNIT = "N/A" DESCRIPTION = "The calendar epoch in ephemeris time of the initial state vector at the spacecraft. The initial state vector is given by SPACECRAFT POSITION and SPACECRAFT VELOCITY below. (program mnemonic CEPOCH)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "JULIAN EPHEMERIS DAYS" DATA_TYPE = ASCII_REAL START_BYTE = 73 BYTES = 23 FORMAT = "E23.16" UNIT = "DAY" DESCRIPTION = "The Julian date corresponding to CEPOCH (ephemeris time at the space- craft) (program mnemonic JED)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT POSITION" ITEMS = 3 ITEM_BYTES = 23 ITEM_OFFSET = 24 DATA_TYPE = ASCII_REAL START_BYTE = 97 BYTES = 71 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "The spacecraft position vector at CEPOCH, calculated in program ODP (program mnemonics XS, YS, and ZS)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT VELOCITY" ITEMS = 3 ITEM_BYTES = 23 ITEM_OFFSET = 24 DATA_TYPE = ASCII_REAL START_BYTE = 169 BYTES = 71 FORMAT = "E23.16" UNIT = "KILOMETER PER SECOND" DESCRIPTION = "The spacecraft velocity vector at CEPOCH, calculated in program ODP (program mnemonics DXS, DYS, and DZS)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 241 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric longitude of the spacecraft corresponding to SPACECRAFT POSITION at CEPOCH (program mnemonic LONEP)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT HOUR ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 265 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "The hour angle of the spacecraft corresponding to SPACECRAFT POSITION at CEPOCH (program mnemonic HANG)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DOBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 289 BYTES = 2 FORMAT = "I2" UNIT = "N/A" DESCRIPTION = "Flag for constant (-1) or variable (+1) time spacing in spline fits. If DOBKS=+1, the time intervals in BKTIMX will be unequal." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "RECORD SPACING" DATA_TYPE = ASCII_REAL START_BYTE = 292 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Time spacing of the output records in the RESULTS_TABLE (program mnemonic DTACC). Large values may mean that spacing defaults to the spacing of the data points (no interpolated data)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MINBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 316 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Minimum number of data points in each spline interval (used only if DOBKS=+1)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MAXBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 327 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Maximum number of data points in each spline interval (used only if DOBKS=+1)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "BAND" DATA_TYPE = ASCII_REAL START_BYTE = 338 BYTES = 23 FORMAT = "E23.16" UNIT = "MILLIMETER PER SECOND" DESCRIPTION = "Conversion factor from Doppler to acceleration. Nominally 0.2955 for X-band data and 1.0833 for S-band data." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TADD" DATA_TYPE = ASCII_REAL START_BYTE = 362 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Time from CEPOCH to first data point (at the spacecraft)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TFIT" DATA_TYPE = ASCII_REAL START_BYTE = 386 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Time from TADD to last data point (at the spacecraft)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DFIT" DATA_TYPE = ASCII_REAL START_BYTE = 410 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Length of each spline interval (used only when DOBKS=-1)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REJECT" DATA_TYPE = ASCII_REAL START_BYTE = 434 BYTES = 23 FORMAT = "E23.16" UNIT = "HERTZ" DESCRIPTION = "Threshold for rejection of bad data points." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "EARTH LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 458 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric longitude of Earth at CEPOCH (program mnemonic LNE)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "EARTH LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 482 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric north latitude of Earth at CEPOCH (program mnemonic LTE)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TRANSA" DATA_TYPE = ASCII_REAL START_BYTE = 506 BYTES = 23 FORMAT = "E23.16" UNIT = "SECOND" DESCRIPTION = "One-way downlink light- time for a photon leaving the spacecraft at CEPOCH." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TRANSB" DATA_TYPE = ASCII_REAL START_BYTE = 530 BYTES = 23 FORMAT = "E23.16" UNIT = "SECOND PER SECOND" DESCRIPTION = "Rate of change of TRANSA" END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DUTSEC" DATA_TYPE = ASCII_REAL START_BYTE = 554 BYTES = 23 FORMAT = "E23.16" UNIT = "SECOND" DESCRIPTION = "Difference between ephemeris time (ET) and universal time (UT)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFEP" DATA_TYPE = TIME START_BYTE = 578 BYTES = 23 UNIT = "N/A" DESCRIPTION = "Reference epoch for TRANSA and TRANSB at the spacecraft (same time system, and often the same value, as CEPOCH)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL SEMIMAJOR AXIS" DATA_TYPE = ASCII_REAL START_BYTE = 602 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Semi-major axis of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic SMA)" END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL ECCENTRICITY" DATA_TYPE = ASCII_REAL START_BYTE = 626 BYTES = 23 FORMAT = "E23.16" UNIT = "DIMENSIONLESS" DESCRIPTION = "Eccentricity of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic ECC)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL INCLINATION" DATA_TYPE = ASCII_REAL START_BYTE = 650 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Inclination of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic INC)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ASCENDING NODE LONGITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 674 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Ascending node of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic NODE)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS ARGUMENT ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 698 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Argument of periapsis for spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic ARG)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TRUE ANOMALY ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 722 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "True anomaly of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic F)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MEAN ANOMALY ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 746 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Mean anomaly of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic M)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ECCENTRIC ANOMALY ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 770 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Eccentric anomaly of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic E)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORBITAL PERIOD" DATA_TYPE = ASCII_REAL START_BYTE = 794 BYTES = 23 FORMAT = "E23.16" UNIT = "HOUR" DESCRIPTION = "Period of spacecraft orbit. Obtained in the orbit solution of program ODP (program mnemonic P)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 818 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric north latitude at periapsis for spacecraft orbit (program mnemonic LATPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 842 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Planetocentric longitude of periapsis for spacecraft orbit (program mnemonic LONPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 866 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft distance from target center of mass at periapsis (program mnemonic RPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS VELOCITY" DATA_TYPE = ASCII_REAL START_BYTE = 890 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER PER SECOND" DESCRIPTION = "Spacecraft velocity at periapsis (program mnemonic VPER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PERIAPSIS ALTITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 914 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft altitude over reference surface at periapsis (program mnemonic APER)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "APOAPSIS RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 938 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft distance from target center of mass at apoapsis (program mnemonic RAPO)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "APOAPSIS VELOCITY" DATA_TYPE = ASCII_REAL START_BYTE = 962 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER PER SECOND" DESCRIPTION = "Spacecraft velocity at apoapsis (program mnemonic VAPO)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "APOAPSIS ALTITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 986 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft altitude over reference surface at apoapsis (program mnemonic AAPO)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NBKS" DATA_TYPE = ASCII_INTEGER START_BYTE = 1010 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Number of times in the Times Table defining spline intervals." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NPOINT" DATA_TYPE = ASCII_INTEGER START_BYTE = 1021 BYTES = 10 FORMAT = "I10" UNIT = "N/A" DESCRIPTION = "Number of data points used to make this file." END_OBJECT = COLUMN END_OBJECT = LOSAPDR_HEADER_TABLE OBJECT = LOSAPDR_TIMES_TABLE ROWS = 5 COLUMNS = 1 ROW_BYTES = 23 ROW_SUFFIX_BYTES = 179 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The LOSAPDR times table contains exact times bounding each spline interval. Each row contains one 23-digit number, 177 spaces, and a carriage-return line-feed pair." OBJECT = COLUMN NAME = "SPLINE BREAK TIMES" DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "The exact times of spline interval boundaries measured from midnight at the spacecraft (program mnemonic BKTIMX)." END_OBJECT = COLUMN END_OBJECT = LOSAPDR_TIMES_TABLE OBJECT = LOSAPDR_RESULTS_TABLE ROWS = 11 COLUMNS = 11 ROW_BYTES = 202 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The LOSAPDR Results Table contains the results from spline fits to Doppler tracking residuals. Each row in the table contains times, Doppler residuals, spacecraft position information, residuals to spline fits, and inferred spacecraft acceleration with respect to the nominal Keplerian orbit. Each row has length 202 bytes; the first 200 are column data delimited by commas; the last two are a carriage- return line-feed pair." OBJECT = COLUMN NAME = "HH" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 2 FORMAT = "I2.2" UNIT = "HOUR" DESCRIPTION = "The hour of a Doppler residual data point at the spacecraft." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MM" DATA_TYPE = ASCII_INTEGER START_BYTE = 4 BYTES = 2 FORMAT = "I2.2" UNIT = "MINUTE" DESCRIPTION = "The minute of a Doppler residual data point at the spacecraft." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SS" DATA_TYPE = ASCII_INTEGER START_BYTE = 7 BYTES = 2 FORMAT = "I2.2" UNIT = "SECOND" DESCRIPTION = "The whole seconds of a Doppler residual data point at the spacecraft. Note that there are generally fractional seconds; for full time accuracy use OFFSET TIME." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "OFFSET TIME" DATA_TYPE = ASCII_REAL START_BYTE = 10 BYTES = 23 FORMAT = "E23.16" UNIT = "MINUTE" DESCRIPTION = "Offset from CEPOCH to the time of the Doppler residual data point or inter- polation (program mnemonic DMIN)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DOPPLER RESIDUAL" DATA_TYPE = ASCII_REAL START_BYTE = 34 BYTES = 23 FORMAT = "E23.16" UNIT = "HERTZ" DESCRIPTION = "Doppler residual from input data (program mnemonic DATA_RESID)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT ALTITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 58 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "Spacecraft altitude over reference surface (program mnemonic SC_ALT)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 82 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Spacecraft planetocentric north latitude (program mnemonic SC_LAT)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SPACECRAFT LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 106 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "Spacecraft planetocentric longitude (program mnemonic SC_LON)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "FIT RESIDUAL" DATA_TYPE = ASCII_REAL START_BYTE = 130 BYTES = 23 FORMAT = "E23.16" UNIT = "HERTZ" DESCRIPTION = "Doppler residual from fitted spline at HHMMSS (program mnemonic FIT_RESID)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ACCELERATION" DATA_TYPE = ASCII_REAL START_BYTE = 154 BYTES = 23 FORMAT = "E23.16" UNIT = "MILLIMETER PER SECOND PER SECOND" DESCRIPTION = "Acceleration from fitted Doppler residual (program mnemonic ACCEL)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ACCELERATION UNCERTAINTY" DATA_TYPE = ASCII_REAL START_BYTE = 178 BYTES = 23 FORMAT = "E23.16" UNIT = "MILLIMETER PER SECOND PER SECOND" DESCRIPTION = "Uncertainty in the acceleration from the fitted Doppler residual." END_OBJECT = COLUMN END_OBJECT = LOSAPDR_RESULTS_TABLE END CCSD $$MARKER##mark##NJPL3IF0003000000001 B.2 Example Data Object The example below shows an example Header Table, Times Table, and Results Table from an example Data Object. 6.0510000000000000E+03, 3.2485860000000000E+05,1992-01-19T10:27:24.80 0, 2.4486409357025790E+06,-1.2963281519810170E+04, 5.9729359248345210E +03,-2.7018905642057470E+03,-0.7526057204660967E+00,-2.673449985560406 2E-03, 3.6049836857520860E+00, 1.5526173470021440E+02, 1.4226495204046 240E+02,-1, 0.2500000000000000E+00, 6, 12, 0.2955000000 000000E+00, 6.7698640000000000E+01, 6.0000000000000000E+01, 1.70000000 00000000E+00, 1.0000000000000000E+01, 2.9836450000000000E+02,-6.857677 0000000000E-01, 6.1625350000000000E+02, 0.0000000000000000E+00, 5.8184 440000000000E+01,1992-01-19T10:27:24.000, 1.0424287716205380E+04, 3.93 53649445226273E-01, 8.5142622632185550E+01,-6.1551568027322280E+01, 1. 6924171180858060E+02,-1.7999999999923740E+02,-1.7999999999838910E+02,- 1.7999999999884400E+02, 3.2591156211841630E+00,-1.0719192274082790E+01 ,-2.4738266181368390E+01, 6.3219500712043310E+03, 8.4621546045242220E+ 00, 2.7095007120433070E+02, 1.4526625361206430E+04, 3.6827068683533140 E+00, 8.4756253612064300E+03, 5, 11.................... ...................................................................... ...................................................................... .................... 6.9511138916015630E+02............................................... ...................................................................... ............................................................ 6.9681140136718750E+02............................................... ...................................................................... ............................................................ 6.9851141357421880E+02............................................... ...................................................................... ............................................................ 7.0021142578125000E+02............................................... ...................................................................... ............................................................ 7.0191143798828130E+02............................................... ...................................................................... ............................................................ 11,43,12, 7.5786000000000000E+01,-1.7000000000000000E-02, 2.3225380000 000000E+03, 8.4213000000000000E+01,-1.4683400000000000E+02,-1.79343000 00000000E-02,-2.9310000000000000E-02, 1.0000000000000000E-03 11,43,24, 7.5837000000000000E+01,-2.3000000000000000E-02, 2.3152700000 000000E+03, 8.4285000000000000E+01,-1.4570200000000000E+02,-1.93232000 00000000E-02,-2.9510000000000000E-02, 1.0000000000000000E-04 11,43,36, 7.6087000000000000E+01, 0.1100000000000000E-03, 2.2797780000 000000E+03, 8.4603000000000000E+01,-1.3972800000000000E+02,-2.62324000 00000000E-02,-3.0320000000000000E-02, 1.0000000000000000E-05 11,43,48, 7.6337000000000000E+01,-0.4100000000000000E-02, 2.2443480000 000000E+03, 8.4858000000000000E+01,-1.3303000000000000E+02,-3.33028000 00000000E-02,-3.0950000000000000E-02, 1.0000000000000000E-06 11,44,00, 7.6587000000000000E+01,-7.5500000000000000E-02, 2.2089830000 000000E+03, 8.5037000000000000E+01,-1.2568300000000000E+02,-4.05298000 00000000E-02,-3.1710000000000000E-02, 1.0000000000000000E-07 11,44,12, 7.6786000000000000E+01,-4.7400000000000000E-02, 2.1809040000 000000E+03, 8.5119000000000000E+01,-1.1948400000000000E+02,-4.64162000 00000000E-02,-3.2440000000000000E-02, 1.0000000000000000E-08 11,44,24, 7.6837000000000000E+01, 8.1900000000000000E-03, 2.1736890000 000000E+03, 8.5131000000000000E+01,-1.1785500000000000E+02,-4.79530000 00000000E-02,-3.2650000000000000E-02, 1.0000000000000000E-09 11,44,36, 7.7087000000000000E+01,-6.4100000000000000E-03, 2.1384740000 000000E+03, 8.5131000000000000E+01,-1.0980700000000000E+02,-5.56132000 00000000E-02,-3.3770000000000000E-02, 1.0000000000000000E-10 11,44,48, 7.7337000000000000E+01, 9.0500000000000000E_03, 2.1033410000 000000E+03, 8.5035000000000000E+01,-1.0184500000000000E+02,-6.35515000 00000000E-02,-3.5060000000000000E-02, 1.0000000000000000E-11 11,45,00, 7.7587000000000000E+01, 1.1000000000000000E-02, 2.0682950000 000000E+03, 8.4847000000000000E+01,-9.4259000000000000E+01,-7.18089000 00000000E-02,-3.6530000000000000E-02, 1.0000000000000000E-12 11,45,12, 7.7786000000000000E+01,-7.8400000000000000E-02, 2.0404870000 000000E+03, 8.4635000000000000E+01,-8.8637000000000000E+01,-7.86319000 00000000E-02,-3.7830000000000000E-02, 1.0000000000000000E-13