PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH FILE_RECORDS = 64800 RECORD_BYTES = 58 ^TABLE = "IEG100_A.TAB" DATA_SET_ID = "MGS-M-MOLA-5-IEGDR-L3-V1.0" PRODUCT_ID = "MOLA-IEG100_A.TAB" SPACECRAFT_NAME = MARS_GLOBAL_SURVEYOR INSTRUMENT_ID = MOLA INSTRUMENT_NAME = MARS_ORBITER_LASER_ALTIMETER TARGET_NAME = MARS START_TIME = 1997-09-15T19:10:00.000 STOP_TIME = 1999-05-31T23:59:59.999 START_ORBIT_NUMBER = 3 STOP_ORBIT_NUMBER = 11027 PRODUCT_CREATION_TIME = 1999-10-18T20:05:00.000 PRODUCER_ID = MGS_MOLA_TEAM PRODUCER_FULL_NAME = "DAVID E. SMITH" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" DESCRIPTION = "This data set is a topographic map of Mars at a resolution of 1 by 1 degree, based on altimetry data acquired by the Mars Global Surveyor MOLA instrument and accumulated over the course of the mission so far. The MOLA Precision Experiment Data Records (PEDRs) are the source for this data set. The map is in the form of an ASCII table with one row for each 1 by 1 degree latitude-longitude bin, from 90 to -90 degrees latitude and from 0 to 360 degrees longitude. The binned data include all MOLA nadir observations from the Orbit Insertion phase, plus Mapping Phase nadir observations from the beginning of mapping through the end of May 1999, plus off-nadir observations of the north pole above 86 degrees latitude acquired during spring 1998. Orbits 355 and 358 of the Orbit Insertion Phase and orbits 10709 through 10716, inclusive, of the Mapping Phase are excluded because solutions for these orbits are deemed to be poor. (Note: subtract 10000 from MOLA mapping phase orbit number to determine the equivalent MGS Project orbit number.) Also excluded are shots more than 1 degree off-nadir (except as noted above), channel 4 returns, and any returns not classified as ground returns, e.g. clouds or noise, according to the SHOT_CLASSIFICATION_CODE. A total of 52,495,550 observations are represented." OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 64800 ROW_BYTES = 58 COLUMNS = 6 OBJECT = COLUMN NAME = AREOCENTRIC_LONGITUDE DATA_TYPE = REAL START_BYTE = 1 BYTES = 8 FORMAT = "F8.1" UNIT = DEGREE MINIMUM = 0.5 MAXIMUM = 359.5 DESCRIPTION = "Areocentric east longitude of the center of the 1 by 1 degree area of observation. The rows in the table are in order by increasing longitude (0.5 to 359.5) and decreasing latitude (89.5 to -89.5), with longitude varying first." END_OBJECT = COLUMN OBJECT = COLUMN NAME = AREOCENTRIC_LATITUDE DATA_TYPE = REAL START_BYTE = 9 BYTES = 8 FORMAT = "F8.1" UNIT = DEGREE MINIMUM = -89.5 MAXIMUM = 89.5 DESCRIPTION = "Areocentric latitude of the center of the 1 by 1 degree area of observation. The rows in the table are in order by increasing longitude (0.5 to 359.5) and decreasing latitude (89.5 to -89.5), with longitude varying first." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MEAN_PLANETARY_RADIUS DATA_TYPE = REAL START_BYTE = 17 BYTES = 12 FORMAT = "F12.2" UNIT = METER MINIMUM = 3373396.58 MAXIMUM = 3416455.71 DESCRIPTION = "Mean observed planetary radius within the 1 by 1 degree area. Where no observations lie within the area, an interpolated value is supplied. The mean of the observations is provided as an areodetically useful average, while the median is used for topography." END_OBJECT = COLUMN OBJECT = COLUMN NAME = AREOID_RADIUS DATA_TYPE = REAL START_BYTE = 29 BYTES = 12 FORMAT = "F12.2" UNIT = METER MINIMUM = 3378182.02 MAXIMUM = 3397474.00 DESCRIPTION = "Areoid radius at the center of the 1 by 1 degree area of observation. The areoid radius lies on an equipotential surface whose mean radius at the equator is 3396000 meters. The surface is defined by the Goddard Mars Potential Model MGM0964C20, evaluated to degree and order 50." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MEDIAN_TOPOGRAPHY DATA_TYPE = REAL START_BYTE = 41 BYTES = 10 FORMAT = "F10.2" UNIT = METER MINIMUM = -7501.22 MAXIMUM = 20882.70 DESCRIPTION = "Median observed topography within the 1 by 1 degree area. Where no observations lie within the area, an interpolated value is supplied. The minimum and maximum topography observations within the current data set are -8162.04 and 21223.5. Topography is the planetary radius minus the areoid radius at a longitude and latitude. The areoid radius at the center of the area is not, in general, the same as the mean of the areoid radii at the individual observations. Moreover, the median observed topography follows sharp transitions in height more rapidly than the mean. Thus, the median topography added to the areoid radius is not exactly equal to the mean planetary radius." END_OBJECT = COLUMN OBJECT = COLUMN NAME = OBSERVATIONS DATA_TYPE = INTEGER START_BYTE = 51 BYTES = 6 FORMAT = "I6" MINIMUM = 0 MAXIMUM = 2152 DESCRIPTION = "Number of observations in the 1 by 1 degree area." END_OBJECT = COLUMN END_OBJECT = TABLE END