Mars Global Surveyor:
Precision Experiment Data Records
PEDRs are generated from the raw
altimetry profile data (AEDRs) with precision orbit
corrections applied. They are time-ordered binary tables
with attached PDS labels.
Tools for Use with PEDR Products
Mars Orbital Data
accepts queries of PEDR products by
latitude, longitude, altitude, orbit, and
time, and returns the selected altimetry
data in tabular form, as a binned image, or
as shapefiles for use with GIS tools.
IDL and Fortran software is available to read and extract data
from PEDR files.
PEDR Data Online
Use the links below for direct access
to any part of the MOLA PEDR archive. Or follow
this link for
FTP access to this data set. (FTP users, read
our FTP instructions
||Notes and errata
for the archive
||An index to all
information, including descriptions of the data
set and instrument, along with references
||Software to read
PEDR binary data files
data columns in PEDR files
Note on PEDR Processing Versions
The processing software used to
generate MOLA PEDRs was updated as better orbit
information became available during the mission. The
processing version of a given PEDR is indicated by the
last character of the file name (before the period). For
example, AP10146L.B is version L. (Versions increase
alphabetically.) PEDRs processed with different software
versions have only minor differences, but users should
be aware that the multiple versions exist. Processing
version L is the last version, released May 27, 2003.
Version L uses IAU2000 planetocentric coordinates,
incorporates crossover analysis of individual profiles,
and is referenced to the latest Mars gravity model.
All PEDR products on this web site have been reprocessed
to version L, to provide a complete set of PEDRs with a
consistent processing history. These products are
intended to replace previously released PEDRs, found on
CD-ROM volumes MGSL_0001 through MGSL_2054.
The first two MOLA CD-ROM volumes, MGSL_0001 and
MGSL_0002, and the MGS Sampler CD contained versions of
PEDRs in ASCII tables as well as binary. This proved to
be an impractical storage format, so later volumes did
not include the ASCII versions. The data in the ASCII
files have been superseded by the present PEDR data set.
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