urn:nasa:pds:mgs_mola_topography_derived:data_megdr_polar:megr_n_128 1.0 1.23.0.0 Product_Observational 2026 This data product is a shape map of the north pole of Mars at a resolution of 128 pixels per degree, based on altimetry data acquired by the Mars Global Surveyor MOLA instrument and accumulated over the course of the primary and extended mission. Producer David E. Smith Goddard Space Flight Center, MOLA Team DataCurator Madison N. Hughes Washington University in St. Louis 2026-08-25 1.0 Initial PDS4 version 1997-09-15T19:10:00.000Z 2001-06-30T11:10:40.000Z Mars Global Surveyor Mission urn:nasa:pds:context:investigation:mission.mars_global_surveyor data_to_investigation MOLA The Mars Global Surveyor Spacecraft Host urn:nasa:pds:context:instrument_host:spacecraft.mgs is_instrument_host Mars Global Surveyor Spacecraft Mars Orbiter Laser Altimeter Instrument urn:nasa:pds:context:instrument:mgs.mola is_instrument Mars Planet urn:nasa:pds:context:target:planet.mars data_to_target 3 20333 gridded_image cartography_parameters_to_image_object Polar Stereographic 0 90 Coordinate Pair 0.46 0.46 128 128 Planetocentric 3396 3396 3396 Positive East Body-fixed Rotating PLANETOCENTRIC gridded_image display_settings_to_array Sample Left to Right Line Top to Bottom 1999-08-08T03:10:20.000Z 1997-09-15T19:10:00.000Z 2001-06-30T11:10:40.000Z Mars Planetocentric Mars IAU2000_MARS megr_n_128.img 2006-03-01T01:00:00 This data product is a shape map of the north pole of Mars at a resolution of 128 pixels per degree, based on altimetry data acquired by the Mars Global Surveyor MOLA instrument and accumulated over the course of the primary and extended mission. The MOLA Precision Experiment Data Records (PEDRs) are the source for this data set. Map coordinates use the IAU2000 reference system. The binned data include all MOLA nadir observations from the Mapping Phase through the Primary and Extended missions, from the end of aerobraking in February 1999 through June 2001. Additionally, off-nadir observations of the north pole are included from 87 N latitude and northward, taken during the spring of 1998, and during Mapping from 87 N to the pole. The number of samples in each bin is given in the MEGC_N_128.IMG data product. Since the projection of radius to a polar map view is nonstandard, it should be pointed out that there is no flattening assumed and the MAP_SCALE is approximate. The pixel {x, y} coordinates are given by 2*sin[0.5 * colatitude]*{sin[longitude],cos[longitude]}*MAP_RESOLUTION +0.5*{(LINE_SAMPLES+1),(LINES+1)}. The first pixel lies at 37.4532N, 225E. gridded_image 0 2 Last Index Fastest IEEE754MSBSingle meter Line 10240 1 Sample 10240 2 megr_n_128.lbl 0 PDS3 Original PDS3 label. Carriage-Return Line-Feed megr_n_128.hdr 0 7-Bit ASCII Text The ENVI header is a separate ASCII file that includes basic image data file characteristics. ENVI will read both files and use the map projection information in the header file to correctly display the image. The header files are provided because ENVI is not able to import the map projection information directly from the MEGDR image labels. Carriage-Return Line-Feed