NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
Ames Research Center
Moffett Field, California
PIONEER VENUS PROJECT
SPECIFICATION PC-456.O4
PIONEER VENUS: DATA USER REQUIREMENTS
FOR SUPPLEMENTARY EXPERIMENTER DATA RECORDS
May 15, 1976
l. SCOPE
This specification defines the requirements of each of the Pioneer
Venus data users for the Supplementary Experimenter Data Records (SEDR).
2. APPLICABLE DOCUMENTS
2.1 NASA/ARC SPECIFICATIONS
PC-456.OO, Pioneer Venus: Data Records Processing System (DRPS)
Description
PC-456.O1, Pioneer Venus: Input and Output Tape Description
PC-456.O2, Pioneer Venus: Data Records Processing System (DRPS)
Detailed Processing Requirements
PC-456.O3, Pioneer Venus: Data User Requirements for Experimenter
Data Records
PC-454.OO, Pioneer Venus: On-Line Ground Data System Software
Specification
PC-455.OO, Pioneer Venus: Off-Line Telemetry Data Processing
Specification
-1-
Section No. 3.0
Doc. No. YL-430.U4
Orig. Issue Date 7/20/77
Revision No. 3
Revision
3. REQUIREMENTS
3.1 GENERAL REQUIREMENTS
The general requirements and content for the Supplementary Experimenter
Data Records have been covered in PC-456.O1 Pioneer Venus: Input and
Output Tape Requirements.
3.2 SPECIFIC REQUIREMENTS
The SEDR formats for all data users shall conform to the specification
given below. In the case of the Orbiter Spacecraft, the SEDR shall be
generated periodically from launch through mission completion. The
Multiprobe Spacecraft SEDR shall be generated periodically from launch
up until probe separation. A predicted model trajectory shall be
generated for each of the probes after separation, from planet entry to
impact in a format TBS.
Details on the use of the various tables defined in the SEDR format
and the QLSEDR format are described in Section 6.3 of this specification.
Coordinate System diagrams in the trajectory portion of the format are in
Figures 3.2 Sheets 1 through 8.
3.2.1 Production SEDR. The SEDRs� for both spacecraft shall contain
measured or true trajectory data as shown in Figure 3.2.1 sheets
1 through 1O. These data shall be in IBM 360 Double Precision
Floating Point formats.
3.2.2 Quick Look SEDR (QLSEDR). The best available data at the time the
Quick Look SEDRs are being prepared is predicted trajectory data
and will not contain the resolution that the production SEDRs will
contain. The Logistics file shall be identical to that described
above. The data file shall contain only 24 of the variables that
are in the normal production SEDR. Since the variables are predicted,
these selected variables shall be in IBM 360 Single Precision Floating
Point formats. The format and variables which shall be carried in
the QLSEDR are shown in Figure 3.2.2 sheets 1 through 7.
3.3 SEDR TAPE DELIVERY
SEDR tapes shall be sent to each addressee shown in Figure 3.4 of
Specification PC-456.O3.
Section No. 6.3.1.2.1
Doc. No. PC-456.O4
Orig. Issue Date 7/20/77
Revision No. 3
Revision
6.3.1.2.1 Measured SRR Times. For some SRR pulses, one of the telemetered
ATTM measurements will contain the time interval between the
SRR pulse and the beginning of the major telemetry frame which
immediately follows. For these SRR pulses, the time of the SRR
pulse is calculated by:
TSRR = TMAJ - (telemetered time interval)
TMAJ is the Spacecraft Universal Time (SCUT) of the beginning
of the major telemetry frame.
6.3.1.2.2 Estimated SRR Times. For about half of the SRR pulses, no time
interval measurement will be made. For these pulses, the time of
the SRR pulse is estimated by:
TSSR(est) = TSRR (last measured) + (n) (spin period)
TSRR (last measured) is the SCUT of the last SRR pulse for
which a measured time interval was telemetered.
Spin period is the spacecraft spin period from Table 3. n is the
integer number of spin periods which have elapsed since the last
measured SRR pulse.
6.3.1.3 Smoothed Roll Reference Times (Fs). An Fs signal follows each
SRR pulse. The time of the Fs signal is calculated by:
TFs = TSRR + delta
delta is the time delay from SRR to Fs from Table 3.
6.3.1.4 Roll Index Pulse Times (RIP). A RIP pulse follows each Fs signal.
The time of the RIP pulse is calculated by:
TRIP = TFS + (RIP time delay)
(RIP time delay) is the current value of the time from Fs to RIP
as determined from the telemetered measurement ARIPAD. (RIP time
delay) = (decimal value of ARIPAD) (Spin Period)/1024
Spin period is the spacecraft spin period from Table 3.
Section No. 6.3.1.5
Doc. No. PC-456.04
Orig. Issue Date 7/20/77
Revision No. 3
Revision
6.3.1.5 Ram Pulse Times (RAM). A RAM pulse follows each RIP pulse. The
time of the RAM pulse is calculated by:
TRAM = TRIP + (RAM time delay)
(RAM time delay) is the value of the RAM time delay at the RIP
time. The RAM time delay at the time of the beginning of each
major telemetry frame is calculated from the telemetered
measurement AVPDRD by:
RAM time delay= (decimal value of AVPDRD) x (spin period)/4096
The RAM time delay at the RIP time is interpolated to the RIP time
from the telemetered measurements.
(spin period) is the spacecraft spin period from Table 3.
6.3.1.6 NADIR Pulse Times (NADIR). A NADIR pulse follows each RIP pulse.
The time of the NADIR pulse is calculated by:
TNADIR = TRIP + (NADIR time delay)
(NADIR time delay) is the value of the NADIR time delay at the
RIP time.
The NADIR time delay at the time of the beginning of each major
telemetry frame is calculated from the telemetered measurement
AVPDND by:
NADIR time delay = (decimal value at AVPDND) x (spin period)/4096
(spin period if the spacecraft spin period from Table 3).
The NADIR time delay at the RIP time is interpolated to the RIP
time from the telemetered measurements.
Section No. 6.3.2
Doc. No. PC-456.04
Orig. Issue Date 7/20/77
Revision No. 3
Revision
6.3.2 Pulse Times - Table 1. The times of one complete set of roll
reference signals shall be included in Table 1 of the SEDR tape
and QL Tape. For the Orbiter spacecraft, one complete set of
roll reference signals shall include an Fs signal, the RIP
pulse which is based on that Fs signal and the RAM and NADIR
pulses which are based on the RIP pulse. For the Bus spacecraft,
one complete set of roll reference signals shall include an Fs
signal and the RIP pulse which is based on that Fs signal. A
separate data record shall be included in the tape for each set
of roll reference signals which occur during the time span of the
data.
The signal times shall be the SCUT of each signal which have been
calculated from the telemetry record as described in section 6.3.1.
6.3.3 Spacecraft Attitude. Table 2 shall tabulate the celestial latitude
and celestial longitude of the spacecraft spin axis. The entries
in the table will be provided as input and will not be calculated.
Interpolation for spin axis attitude at times between the tabulated
times shall be by using the technique described in section 6.3.6.
6.3.4 Spacecraft Spin Period - Table 3. Table 3 shall tabulate the
spacecraft spin period and associated time delay (section 6.3.1.3).
The entries in this table will be provided as input and will not
be calculated. Linear interpolation may be used to estimate spin
period and time delay at times between the entries in the table.
6.3.5 SRR Epochs - Table 4. Table 4 shall tabulate the positions of
roll reference celestial bodies. The entries in this table will
be input and will not be calculated. If the telemetry measurement
ASRRMS indicates that a star is being used for the roll reference,
the star celestial latitude and celestial longitude will be included
in Table 4. If the telemetry measurement ASRRMS indicates that the
Simulated ROll Reference (SIM SRR) is being used, the error
between the Sun and the Sim SRR will be tabulated. Table 4 will
contain enough entries to model any Sim SRR drift and allow linear
interpolation between entries.
The use of Table 4 to calculate spacecraft roll angle is described
in section 6.4.
Section No. 6.3.6
Doc. No. PC-456 04
Orig. Issue Date 7/20/77
Revision No. 3
Revision
6.3.6 Vector Interpolation for Spacecraft Attitude.
6.3.6.1 Interpolation Requirement. If the spacecraft spin axis attitude is
needed at a time which is between the times for which Table 2
contains tabulated values, the intermediate attitude must be
interpolated as a vector: the attitude must be interpolated in the
plane which contains the two tabulated vectors.
6.3.6.2 Vector Representation of Attitudes. Let T be the time at which
the interpolated attitude is desired. Let Tl and T2 be the times
at which the spin axis attitude is tabulated in Table 2.
[T1 < T < T2]
ATT1 = vector spin axis attitude at time T1
ATT2 = vector spin axis attitude at time T2
ATT = vector spin axis attitude at time T
ATT1X, ATT1Y, ATT1Z = X, Y, Z component of ATT1
ATTlX = cos (CLAT1) cos (CLON1)
ATT1Y = cos (CLAT1) sin (CLON1)
ATT1Z = sin (CLAT1)
ATT2X, ATT2Y, ATT2Z = X, Y, Z components of ATT2
ATT2X = cos (CLAT2) cos (CLON2)
ATT2Y = cos (CLAT2) sin (CLONZ)
ATT2Z = sin (CLAT2)
ATTX, ATTY, ATTZ = X, Y, Z components of the interpolated vector ATT
Figure 6.3.6.2 shows the vector relations.
Section No. 6.3.6.3
Doc. No. PC-456.O4
Orig. Issue Date 7/20/17
Revision No. 3
Revision
6.3.6.3 Minimum Angle between Vectors. Check that the angle between
ATT1 and ATT2 is large enough to avoid a zero divisor later.
MAGDIF = [(ATT2X - ATT1X)2 + (ATT2Y - ATT1Y)2 + (ATT2Z - ATT1Z)2112
If MAGDIF less than O.OOO17 set
ATTX = ATT1X
ATTY = ATT1Y
ATTZ = ATT1Z
6.3.6.4 Interpolation Equations.
BIGANG = 2 sin-1 (MAGDIF/2)
RATIO = (T-T1)/(T2 - T1)
LILANG = (BIGANG) (RATIO)
ATTX = (ATT2X - ATT1X cos (BIGANG)) RATIO + ATT1X cos (LILANG)
ATTY = (ATT2Y - ATT1Y cos (BIGANG)) RATIO + ATT1Y cos (LILANG)
ATTZ = (ATT2Z - ATT1Z cos (BIGANG)) RATIO + ATT1Z cos (LILANG)
6.3.6.5 Interpolated Attitude.
CLAT = interpolated celestial latitude
CLAT = sin-1 (ATTZ)
CLON = interpolated celestial longitude
CLON = tan-1 (ATTY)/ATTX
6.3.6.6 Attitude Data. When spacecraft attitude is interpolated to the
epochs of the SEDR Ephemeris, include the components of ATT in
the Ephemeris Data File.
Ephemeris File Ephemeris File
Interpolated component Variable Words
ATTX 63 124 and 125
ATTY 64 126 and 127
ATTZ 65 128 and 129
When spacecraft attitude is interpolated to the epochs of the
Quick Look Data Record, include the components of ATT in the
Ephemeris Record, File 6.
Section No. 6.3.6.6
Doc. No. PC-454.O4
Orig. Issue Date 7-20-77
Revision No. 3
Revision
Interpolated component Ephemeris File Word
ATTX 18
ATTY 19
ATTZ 20
_____________________________________
PRL LRL P/L FILE I.D.
_____________________________________
FILE l LOGISTICS RECORD
(EBCDIC)
_____________________________________
EOF
_____________________________________
PRL LRL P/L FILE I.D.
_____________________________________
PT11 RECORD
FILE 2
_____________________________________
PT11 RECORD
_____________________________________
EOF
_____________________________________
PRL LRL P/L FILE I.D.
_____________________________________
AT12 RECORD
_____________________________________
FILE 3
AT12 RECORD
_____________________________________
EOF
_____________________________________
PRL LRL P/L FILE I.D.
_____________________________________
FILE 4 SP13 RECORD
_____________________________________
5P13 RECORD
_____________________________________
EOF
_____________________________________
PRL LRL P/L FILE I.D.
_____________________________________
SR14 RECORD
_____________________________________
FILE 5
SR14 RECORD
_____________________________________
EOF
_____________________________________
PRL LRL P/L FILE I.D.
_____________________________________
EPHEMERIS RECORD
(ORBIT TODAY)
_____________________________________
FILE 6
EPHEMERIS RECORD
_____________________________________
EOF
_____________________________________
EOF
_____________________________________
PIONEER VENUS SEDR TAPE
FORMAT DEFINITION
REV.NO. 3 DATE 1/20/78
For Definitions
Refer to Log
WORD 0 WORD 1 WORD 2 WORD 3 WORD 4 WORD 5 File Table
|-----------------------------------------------| --------------
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|
|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|
|-----------------------------------------------|
RECORD 1 | *LH WD| |
2 | * P I O N E E R V E N U S S E D R * |
3 | |
4 | T A P E S E Q U E N C E N O . X X X X | 7
5 | |
6 | | 1
7 | S / C I D X X | 7
8 | O R B I T N O X X X X | 7
9 | |
10 | |
11 | |
12 | |
13 | |
14 | |
15 | |
16 | G E N E R A T E D M M M D D , Y Y | 2,7
17 | S T A R T D A T E D O Y , Y Y | 7
18 | S T A R T T I M E H H : M M | 7
19 | S T O P D A T E D O Y , Y Y | 7
20 | S T O P T I M E H H : M M | 7
21 | |
22 | D Q I P ( O R ) A | 8
|-----------------------------------------------|
WORD 0 OF RECORD 1 IS LOGICAL READER WORD
*LH WD = LOGICAL HEADER WORD
DATA FORMAT: EBCDIC
(LRL) LOGICAL RECORD LENGTH: 6 WORDS
*LOGICAL RECORDS IN FILE: 22
(PRL) PHYSICAL RECORD LENGTH: 132
LOGICAL RECORDS PER PHYSICAL RECORD: 22
PIONEER VENUS SEDR FILE DEFINITION Fig 3.2.1
LOGISTIC FILE RECORD FORMAT
REV.NO. 3 DATE 1/20/78
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0| PRL | LRL (#words) | P/L | |
1| Number of Logical Records in This File | |
2| (SPARE) | S/C I.D. | |
3| ORBIT NUMBER | |
4| YEAR | DOY | = HEADER
5| START TIME (DATA) MS BINARY | | RECORD
6| YEAR | DOY | |
7| STOP TIME MS BINARY | |
8| (SPARE) | |
9| (SPARE) | |
10| (SPARE) | |
11| (SPARE) | |
|---------------------------------------------------------------| v
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0|[ YEAR | DOY ] | |
1|[ ms binary (S/C UT of Fs Pulse ] | |
| | |
2|[ YEAR | DOY ] | |
3|[ ms binary (S/C UT of RIP Pulse) ] | |
| | |
4|[ YEAR | DOY ] | = DATA
5|[ ms binary (S/C UT of RAM Pulse ] | | RECORD
| | |
6|[ YEAR | DOY ] | |
7|[ ms binary (S/C UT of NADIR Pulse ] | |
8| DATA QUALITY FLAG 1 Delta - R*8 | |
9| (SPARE) | |
10| A | | B | | C | | D | | |
11| UCLA Pulse time correction (EBCDIC) | |
|---------------------------------------------------------------| v
Logical Record Length : 12 words A: STRM
Data format : Binary B: CICK
Physical Record Length : 120 words C: SRRM
No. Logical Records/Physical Record : 10 D: Fire
SRRM: 0 = unk Fire: 0 = Norm
1 = Star (22,23) 1 = Fire
2 = Sim
3 = Sun
PIONEER VENUS SEDR TAPE FILE FIG 3.2.1
DEFINITION FILE 2
TABLE 1 - PULSE TIMES (Plll)
LOGICAL RECORD FORMAT
REV. NO. 3 DATE 1/20/78
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0| PRL | LRL (#words) | P/L | FILE ID | |
1| Number of logical Records in This File | = HEADER
2| (SPARE) | S/C ID | | RECORD
3| ORBIT NUMBER | |
4| (SPARE) | |
|---------------------------------------------------------------| v
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0|[ S/C UT YEAR DOY ] | |
1|[ ms binary ] | = DATA
2| CLAT (celestial latitude)(in deg. dec deg) | | RECORD
3| CLON (celestial longitude)(in deg. dec deg)| |
4| (SPARE) | |
|---------------------------------------------------------------| v
Logical Record Length : 5 words
Data Format : Single Precision Flt. Pt. Binary
Physical Record Length: 5O words
Logical Records/Physical Record : 10
PIONEER VENUS SEDR TAPE FILE FIG 3.2.1
DEFINITION FILE 3
TABLE 2 - S/C ATTITUDE (ATl2)
LOGICAL RECORD FORMAT
REV. NO. 3 DATE 1/20/78
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0| PRL | LRL (# words) | P/L |FILE I.D | |
1| Number of Logical Records in This File | |
2| (SPARE) | S/C I.D. | |
3| ORBIT NUMBER | = HEADER
4| YEAR | DOY | | RECORD
5| START DATA TIME | MS BINARY | |
6| YEAR | DOY | |
7| STOP DATA TIME | MS BINARY | |
8| SPARE | |
9| SPARE | |
|---------------------------------------------------------------| v
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0|[ S/C UT YEAR | DOY ]| |
1|[ ms binary ]| |
2| SPIN PERI0D (in sec. dec secs) | |
3| TIME DELAY (in sec. dec secs) | = DATA
4| (SPARE) | | RECORD
5| (SPARE) | |
6| (SPARE) | |
7| (SPARE) | |
8| (SPARE) | |
9| (SPARE) | |
|---------------------------------------------------------------| v
Time Delay = delay from SRR Pulse to Fs Pulse.
Logical Record Length: 10 words
Data Format : Single Precision Flt. Pt., Binary
Physical Record Length: 40 words
# Logical Records/Physical Record: 4
PIONEER VENUS SEDR TAPE FILE
DEFINITION FILE 4
TABLE 3 - S/C SPIN RECORD (SPl3)
LOGICAL RECORD FORMAT
REV. NO. 3 DATE 1/20/78
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0| PRL | LRL (# words) | P/L |FILE I.D | |
1| Number of Logical Records in This File | |
2| (SPARE) | S/C I.D. | |
3| ORBIT NUMBER | = HEADER
4| YEAR | DOY | | RECORD
5| START DATA TIME | MS BINARY | |
6| YEAR | DOY | |
7| STOP DATA TIME | MS BINARY | |
8| SPARE | |
9| SPARE | |
|---------------------------------------------------------------| v
BIT
|---------------------------------------------------------------|
| | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^
WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| |
|---------------------------------------------------------------| |
0|[ S/C UT YEAR | DOY ]| |
1|[ ms binary ]| |
2| SPIN PERI0D (in sec. dec secs) | |
3| TIME DELAY (in sec. dec secs) | = DATA
4| (SPARE) | | RECORD
5| (SPARE) | |
6| (SPARE) | |
7| (SPARE) | |
8| (SPARE) | |
9| (SPARE) | |
|---------------------------------------------------------------| v
Logical Record Length : 10 words
Data Format : Single Precision, Flt. Pt. Binary
Physical Record Length : 100 words
#Logical Records/Physical Record : 10
PIONEER VENUS SEDR TAPE FILE
DEFINITIONS FILE 5
TABLE 4 - SRR EPOCHS (SR14)
LOGICAL RECORD FORMAT
REV. NO. 3 DATE 1/20/78
EPHEMERIS HEADER RECORD
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
_________________________________________________________________
word 0| PRL | LRL (# words) | P/L |FILE ID|
|_______________________________________________________________|
1| Number of Logical Records in This File |
|_______________________________________________________________|
2| (spare) | S/C I.D. |
|_______________________________________________________________|
3| ORBIT NUMBER |
|_______________________________________________________________|
4| S/C UT YEAR | DOY S/C UT|
|_______________________________________________________________|
5| START TIME - MILLISECONDS |
|_______________________________________________________________|
6| S/C UT YEAR | DOY S/C UT|
|_______________________________________________________________|
7| STOP TIME - MILLISECONDS |
|_______________________________________________________________|
8| SPARE |
|_______________________________________________________________|
9| SPARE |
|_______________________________________________________________|
.
.
.
_________________________________________________________________
282| SPARE |
|_______________________________________________________________|
283| SPARE |
|_______________________________________________________________|
All data is in IBM 360 binary format, 2 and 4 byte integers
EPHEMERIS DATA RECORD
LOGICAL RECORD LENGTH: 284 1. ALL DATA IS IN IBM 360 format, DP
PHYSICAL RECORD LENGTH: 284 2. Except for integer variables, all
variables are in double-precision
floating point (data
records). including
calculated attitude, nadir
and ram.
NO. OF LOGICAL RECORDS PER
PHYSICAL RECORD: 1 3. File order is in S/C UT
ascending order.
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
WORD __________________________________________________________________________
0 | S/C YEAR | S/C DOY | NAME VAR
|______________________________________________________________|__________
1 | S/C UT in binary |SCUT 1
|______________________________________________________________|__________
2-3|DP Julian Date, Days (elapsed days from |JULDAT
|Noon, 1 Jan. 4713 B.C. | 2
|______________________________________________________________|__________
4-5|Gregorian Calendar Date (2 integer words which |
|represent the vigesimal date) based on number 20 | VIGDAT 3
|______________________________________________________________|__________
6-7|ET - UTC, set (Universal Time Co-ordinated) |ETMUTC 4
|______________________________________________________________|__________
8-9|Range rate of probe. km/sec + |RANGRF 5
|___________________________________________________|__________|__________
10-11|Magnitude of velocity vector, km/sec (speed of S/C)|Geocentric|MAGVEL 6
|___________________________________________________|__________|__________
12-13|Earth.probe range, km (radius to S/C) + |REARPR 7
|______________________________________________________________|__________
14-15|Range to probe, km + |MRANGE 8
|___________________________________________________|__________|__________
16-17|Probe inertia velocity, km/sec | |MMAGVF 9
|___________________________________________________|__________|__________
16-19|Probe inertial path angle, deg |HELIO- |HINFTP 10
|___________________________________________________|CENTRIC __|__________
20-21|Celestial latitude of probe, deg | |CELLTF 11
|___________________________________________________|__________|__________
22-23|Celestial longitude of probe, deg | |CELLNF 12
|___________________________________________________|__________|__________
24-25|Celestial latitude of Earth, deg | |CELLTE 13
|___________________________________________________|__________|__________
26-27|Celestial longitude of Earth, deg | |CELLNE 14
|___________________________________________________|__________|__________
28-29|X component of S/C in Sun-Earth line, km |HELIO- |XSCSEL 15
|___________________________________________________|CENTRIC __|__________
30-31|Y component of S/C in Sun.Earth line, km | |YSCSEL 16
|___________________________________________________|__________|__________
32-33|Z component of S/C in Sun.Earth line, km | |ZSCSEL 17
|___________________________________________________|__________|__________
34-35|Sun-probe distance in Sun-Earth X-Y plane, km | |
|(projection of Sun-S/C vector onto the X-Y plane | |SPSE 18
|___________________________________________________|__________|__________
36-37| Longitude of S/C in Sun-Earth line system, deg + |LNPSEL 19
______________________________________________________________|__________
Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft
and not to the separated Large or Small Probes.
Fig 3.2.1
EPHEMERIS DATA RECORD con't
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var
WORD _________________________________________________________________________
38-39 |X component of geocentric r of S/C, km + |XPGSFF 20
|____________________________________________|________________|__________
40-41 |Y component of geocentric r of S/C, km | |YPGSFF 21
|____________________________________________|________________|__________
42-43 |Z component of geocentric r of S/C, km | |ZPGSFF 22
|____________________________________________|________________|__________
44-45 |X component of geocentric r of S/C, km/sec | |DXPGSF 23
|____________________________________________|________________|__________
46-47 |Y component of geocentric r of S/C, km/sec | |DYPGSF 24
|____________________________________________|________________|__________
46-49 |Z component of geocentric r of S/C, km/sec | |DZPGSF 25
|____________________________________________|________________|__________
50-51 |X component of heliocentric r of S/C, km | |XPHSFF 26
|____________________________________________|________________|__________
52-53 |Y component of heliocentric r of S/C, km | Space-fixed |YPHSFF 27
|____________________________________________| Coordinates ___|__________
54-55 |Z component of heliocentric r of S/C, km | FERP |ZPHSFF 28
|____________________________________________| Earth Mean ___|__________
56-57 |X component of heliocentric r of S/C, km/sec| Equinox & |DXPHSF 29
|____________________________________________| Ecliptic of ___|__________
56-55 |Y component of heliocentric r of S/C, km/sec| 1950.0 |DYPHSF 30
|____________________________________________|________________|__________
60-61 |Z component of heliocentric r of S/C, km/sec| |DZPHSF 31
|____________________________________________|________________|__________
62-63 |X component of body 1 - S/C r, km |+ |XP1SFF 32
|____________________________________________||_______________|__________
64-65 |Y component of body 1 - S/C r, km || |YP1SFF 33
|____________________________________________||_______________|__________
66-67 |Z component of body 1 - S/C r, km || |ZP1SFF 34
|____________________________________________||_ Body __|__________
68-69 |X component of body 1 - S/C r, km/sec || 1 = Venus |DXP1SF 35
|____________________________________________||_______________|__________
70-71 |Y component of body 1 - S/C r, km/sec || |DYP1SF 36
|____________________________________________||_______________|__________
72-73 |Z component of body 1 - S/C r, km/sec || |DZP1SF 37
|____________________________________________||_______________|__________
74-75 |Body 1 - S/C range, km || |B1MAGR 38
|____________________________________________||_______________|__________
76-77 |Body l - S/C velocity magnitude, km/sec ++ |B1MAGV 39
|_____________________________________________________________|__________
78-79 |Latitude of probe, deg + |EALATP 40
|____________________________________________|________________|__________
80-81 |Longitude of probe, deg | |EALOMP 41
|____________________________________________|Body Fixed Earth|__________
82-83 |Velocity magnitude of probe relative to body|(see EN/1) |EAVELP 42
|km/sec. | |
|____________________________________________|________________|___________
84-85 |Body fixed path angle of probe. deg | |EAPTHP 43
|____________________________________________|________________|__________
86-87 |Body fixed azimuth angle of probe. deg + |EAAZIP 44
_________________________________________________________________________
Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft
and not to the separated Large or Small Probes.
EN/1 -- Earth true equator of date and Greenwich Meridian
Fig 3.2.1
EPHEMERIS DATA RECORD con't
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var
WORD _________________________________________________________________________
88-89| Latitude of probe. deg + |B1LATP 45
|___________________________________________|_________________|__________
90-91| Longitude of probe. deg | |B1LOMP 46
|___________________________________________|Body Fixed _|__________
92-93| Velocity magnitude of probe relative to |Body 1 = Venus |B1VELP 47
| body km/sec |(see EN/2) |
|___________________________________________|_________________|__________
94-95| Body fixed path angle of probe. deg | |B1PTHP 48
|___________________________________________|_________________|__________
96-97| Body fixed azimuth angle of probe. deg + |B1AZIP 49
|_____________________________________________________________|__________
98-100| Earth-probe-body 1 angle, deg + |EPB1AN 50
|___________________________________________|_________________|__________
100-101| Earth-probe-sun angle, deg | |EPSUAN 51
|___________________________________________| Angle Group __|__________
102-103| Sun-Earth-probe angle, deg | All angles in |SEPANG 52
|___________________________________________| degrees __|__________
104-105| Earth-Sun-probe angle, deg | |ESPANG 53
|___________________________________________|_________________|__________
106-107| Sun-probe-body 1 angle, deg | |SPB1AN 54
|___________________________________________|_________________|__________
108-109| Body 1-Earth-probe angle, deg + |B1EPAN 55
|_____________________________________________________________|__________
110-111| Flag for periapsis (See EN/3) |PERIAP 56
|_____________________________________________________________|__________
112-113| X-coordinate of XROLL + + |XROLLX 57
|______________________________|____________|_________________|__________
114-115| Y-coordinate of XROLL | | |XROLLY 58
|______________________________|____________|_________________|__________
116-117| Z-coordinate of XROLL | | |XROLLZ 59
|______________________________|____________|_________________|__________
118-119| X-coordinate of YROLL | | |YROLLX 60
|______________________________| Attitude |Spacecraft - ____|__________
120-121| Y-coordinate of YROLL | Data |Centered |YROLLY 61
|______________________________|____________|Non-Rotating ____|__________
122-123| Z-coordinate of YROLL | |Coordinates |YROLLZ 62
|______________________________|____________|_________________|__________
124-125| X-coordinate of ATT | | |ATTX 63
|______________________________|____________|_________________|__________
126-127| Y-coordinate of ATT | | |ATTY 64
|______________________________|____________|_________________|__________
128-129| Z-coordinate of ATT + | |ATTZ 65
|___________________________________________|_________________|__________
130-131| NADROL | |NADROL 66
|___________________________________________|_________________|__________
132-133| NADLOK | |NADLOK 67
|___________________________________________|_________________|__________
134-135| RAMROL | |RAMROL 68
|___________________________________________|_________________|__________
136-137| RAMLOK + |RAMLOK 69
______________________________________________________________|__________
Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft
and not to the separated Large or Small Probes.
EN/2 -- Venus true equator of date and Prime Meridian
EN/3 -- PERIAP = 0. for no closest approach,
= 1 for periapsis to PCB,
= 2 for apoapsis to PCB
Fig 3.2.1
EPHEMERIS DATA RECORD con't
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var
WORD _________________________________________________________________________
138-153| SPARES | 70-77
|_____________________________________________________________|__________
154-155|Celestial latitude of probe, deg + | DECPI 78
|___________________________________________|_________________|__________
156-157|Celestial longitude of probe, deg | | RAP1 79
|___________________________________________|_________________|__________
158-159|Flight-path angle of probe, deg | | PTHP1 80
|___________________________________________|_________________|__________
160-161|Azimuth angle of probe, deg | | AZP1 81
|___________________________________________|_________________|__________
162-163|Range rate of probe. km/sec | | DR1 82
|___________________________________________|_________________|__________
164-165|X-component of Earth position, km | (EC) | XE1 83
|___________________________________________|_________________|__________
166-167|Y-component of Earth position, km | (EC) | YE1 84
|___________________________________________|_________________|__________
168-169|Z-component of Earth position, km | (EC) | ZE1 85
|___________________________________________|_________________|__________
170-171|X-component of Earth velocity, km/sec | (EC) | DXE1 86
|___________________________________________|_________________|__________
172-173|Y-component of Earth velocity, km/sec | (EC) | DYE1 87
|___________________________________________|_________________|__________
174-175|Z-component of Earth velocity, km/sec | (EC) | DZE1 88
|___________________________________________|_________________|__________
176-177|Venus-to-Earth range, km | Venus Centered | RE1 89
|___________________________________________| Earth Mean _|__________
178-179|Celestial latitude of Earth direction, deg | Equinox & | DECE1 90
|___________________________________________| Ecliptic of _|__________
180-181|Celestial longitude of Earth direction, deg| 1950.0 | RAE1 91
|___________________________________________|_________________|__________
182-183|X-component of Sun position. km | (EC) | XS1 92
|___________________________________________|_________________|__________
184-185|Y-component of Sun position, km | (EC) | YS1 93
|___________________________________________|_________________|__________
186-187|Z-component of Sun position, km | (EC) | ZS1 94
|___________________________________________|_________________|__________
188-189|X-component of Sun velocity, km/sec | | DXS1 95
|___________________________________________|_________________|__________
190-191|Y-component of Sun velocity, km/sec | | DYS1 96
|___________________________________________|_________________|__________
192-193|Z-component of Sun velocity, km./sec | | DZS1 97
|___________________________________________|_________________|__________
194-195|Venus-to-Sun range, km | | RS1 98
|___________________________________________|_________________|__________
196-197|Celestial latitude of Sun direction, deg | | DESC1 99
|___________________________________________|_________________|__________
198-199|Celestial longitude of Sun direction. deg + | RAS1 100
|_____________________________________________________________|__________
Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft
and not to the separated Large or Small Probes.
Fig 3.2.1
EPHEMERIS DATA RECORD con't
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var
WORD _________________________________________________________________________
200-201|Orbit semimajor axis, km + + | SMA 101
|_________________________________________|_____|_____________|__________
202-203|Orbit eccentricity | | | ECC 102
|_________________________________________|_____|_____________|__________
204-205|Time from periapsis, secs | | | TFP 103
|_________________________________________|_____|_____________|__________
206-207|Radius of closest approach, km | | | RCA 104
|_________________________________________|_____|_____________|__________
208-209|orbit period, day | | | PER 105
|_________________________________________|Conic|_____________|__________
210-211|Spacecraft true anomaly, deg |Group| | TA 106
|_________________________________________|_____|Venus |__________
212-213|Orbit inclination, deg | |Centered | INCL 107
|_________________________________________|_____|Earth Mean |__________
214-215|Longitude of ascending node, deg | |Equinox & | LANL 108
|_________________________________________|_____|Ecliptic of |__________
216-217|Argument of periapsis, deg | |1950.0 | APF1 109
|_________________________________________|_____|_____________|__________
218-219|X-component of unit vector to periapsis | | | PX1 110
|_________________________________________|_____|_____________|__________
220-221|Y-component of unit vector to periapsis | | | PY1 111
|_________________________________________|_____|_____________|__________
222-223|Z-component of unit vector to periapsis | | | PZ1 112
|_________________________________________|_____|_____________|__________
224-225|X-component of unit normal to orbit plane| | | WX1 113
|_________________________________________|_____|_____________|__________
228-227|Y.component of unit normal to orbit plane| | | WY1 114
|_________________________________________|_____|_____________|__________
228-229|Z-component of unit normal to orbit plane+ | | WZ1 115
|_______________________________________________|_____________|__________
230-231|Sun-Venus-probe angle, deg + | | S200P 116
|_________________________________________|Angle|_____________|__________
232-233|Sun-Earth-Venus angle, deg +Group| | SE200 117
|_______________________________________________|_____________|__________
234-235|X-component of probe position, km | | XP1 118
|_______________________________________________|_____________|__________
236-237|Y-component of probe position, km | | YP1 119
|_______________________________________________|_____________|__________
238-239|Z-component of probe position, km | | ZP1 120
|_______________________________________________|_____________|__________
240-241|X-component of probe velocity, km/sec | | DXP1 121
|_______________________________________________|_____________|__________
242-243|Y-component of probe velocity. km/sec | | DYP1 122
|_______________________________________________|_____________|__________
244-245|Z-component of probe velocity, km/sec + | DZP1 123
|_____________________________________________________________|__________
Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft
and not to the separated Large or Small Probes.
Fig 3.2.1
EPHEMERIS DATA RECORD con't
BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var
WORD _________________________________________________________________________
246-247|X-component of Earth position, km (EQ) + | XE1 124
|_______________________________________________|_____________|__________
248-249|Y-component of Earth position, km (EQ) | | YE1 125
|_______________________________________________|_____________|__________
250-251|Z-component of Earth position, km (EQ) | | ZE1 126
|_______________________________________________|_____________|__________
252-253|X-component of Sun position, km (EQ) | | XS1 127
|_______________________________________________|_____________|__________
254-255|Y-component of Sun position, km (EQ) |Venus | YS1 128
|_______________________________________________|Centered |__________
256-257|Z-component of Sun position, km (EQ) |Earth Mean | ZS1 129
|_______________________________________________|Equinox & |__________
258-259|X-component of probe position, km |Ecliptic of | XP2 130
|_______________________________________________|1950.0 |__________
260-261|Y-component of probe position, km | | YP2 131
|_______________________________________________|_____________|__________
262-263|Z-component of probe position, km | | ZP2 132
|_______________________________________________|_____________|__________
264-265|X-component of probe velocity, km/sec | | DXP2 133
|_______________________________________________|_____________|__________
266-267|Y-component of probe velocity, km/sec | | DYP2 134
|_______________________________________________|_____________|__________
268-269|Z-component of probe velocity. km/sec+ + | DZP2 135
|_____________________________________________________________|__________
270-271|Celestial latitude of Earth-to-probe direction,deg (see EN/4)| DECP3 136
|_____________________________________________________________|__________
272-273|Celestial longitude of Earth-to-probe direction,deg | RAP3 137
|_____________________________________________________________|__________
274-279| (SPARES - Double Precision Zeros) | 138-140
|________________________________________________________________________
EN/4 Earth-centered, Earth mean Equinox & Ecliptic of 1950.0
Fig 3.2.1
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