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Susie Slavney

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Posts posted by Susie Slavney

  1. Hi Emily,

    You don't mention which of the three Mars Climate Sounder (MCS) data sets you are using. If you are looking for surface temperatures, you probably want to use the MCS DDR (Derived Data Record) data set. The primary documentation for this data set is here: https://atmos.nmsu.edu/PDS/data/MROM_2128/DOCUMENT/DP_SIS.PDF. To see if this is the right one, look at Table 2, which describes the columns in the data table. These data tables are ASCII text, so you can open them in any text editor or even in your browser. The columns are also described in a software-readable way in the "format files" in the LABEL directory of the archive, here: https://atmos.nmsu.edu/PDS/data/MROM_2128/LABEL/

    The other two MCS data sets are the RDR (Reduced Data Record) and EDR (Experiment Data Record). EDRs are raw data from the instrument sensors. RDRs are calibrated versions of the EDRs. Finally, the DDRs contain data converted to geophysical units, derived from the RDRs. For each of the three data sets, you'll find an overview of its contents in the file CATALOG/DATASET.CAT, a detailed description in the file DOCUMENT/DP_SIS.PDF, and complete column descriptions in *.FMT files in the LABEL directory. All these files are on the MCS archive volumes, which are hosted at the PDS Atmospheres Node at http://pds-atmospheres.nmsu.edu/data_and_services/atmospheres_data/Mars/Mars.html (scroll down to the MRO section). 

    I hope this is enough to get you started. 

    Susie Slavney

  2. First look in the Orbital Data Explorer's User Manual section on the M3 instrument, here: http://ode.rsl.wustl.edu/moon/pagehelp/quickstartguide/index.html?isros_chandrayaans_m3.htm. At the bottom of the page are some resources for finding and working with M3 data, including the M3 ENVI User's Guide. If you can't find the information you need, please contact the PDS Imaging Node, who archives the M3 data, at https://pds-imaging.jpl.nasa.gov/feedback.html

  3. MRO SHARAD EDR data from the ASI operations facility have been delivered to cover the period February 9, 2013, through August 9, 2014. This is the first of several interim deliveries that will recover the backlog of data from the hiatus of operations that took place between June 2012 and March 2013. See ERRATA.TXT for details. Also, SHARAD radargrams from the U.S. team members have been delivered to cover the period May 12, 2016, through November 6, 2016 (MRO Releases 40 and 41). The data are available on the PDS Geosciences Node web page for SHARAD.

  4. Look near the beginning of the label for a line like ^IMAGE = some-number. That's the record number where the image starts. You also have to know how long a record is; that's in the line RECORD_BYTES = some-number. It's also possible that the offset to the start of the image is given in bytes instead of records; in that case it will look like ^IMAGE = some-number <BYTES>. So for example, if ^IMAGE = 21 and RECORD_BYTES = 128, then you skip the first 20*128=2560 bytes in the file to get to the first byte in the image. It will always start on a record boundary. It doesn't necessarily start right after the END statement in the label; there might be some padding of NUL bytes to fill out the record, or there might be some header records or history records before you get to the image.

  5. Samuel,


    You're right that LINES is the number of lines from top to bottom in the image (i.e. height), LINE_SAMPLES is the number of samples (pixels) in one line (i.e. width), and SAMPLE_BITS is the number of bits per pixel. The other important piece of information is SAMPLE_TYPE = MSB_INTEGER, which tells you each pixel is a signed integer stored in most-significant-byte-first order, which is the usual storage order on a Mac or a Unix-based system. For a Windows system, the usual storage order is LSB, least-significant-byte-first. That means when reading this image on a Windows system you will probably have to swap the two bytes in each pixel. If you display the image and it looks very strange, the first thing to try is swapping the bytes.


    The checksum for the file is a digital signature unique to that file; the simplest type of checksum is the sum of the values of all the bytes in the file. It's not the number of bytes in the file. The checksum is used to make sure the file has been downloaded without corruption. See our page http://pds-geosciences.wustl.edu/dataserv/checksums.html


    Susie Slavney

  6. [From Frank Lemoine, GSFC, in response to a user's request.]


    The radio science data for at least the Mars-orbiting spacecraft and Venus as well (meaning Magellan) and MESSENGER (Mercury) are at the Geosciences Node of the Planetary Data System.


    For example for MRO the direct link is the following URL.




    Or by navigating from the higher level directory.



    The MRO archive has directories labelled "tnf"  -- Raw TRK2-34 data and "odf"  -- Orbit Data File, TRK2-18.


    The TRK2-18 is easier to handle -- the TRK2-34 takes a lot more work to decode. I'm uncertain if there are Delta-DOR data included in these data files.


    The TRK2-18 data is 1 sec -- and contains a 4-5 sec signal that seems to emanate from a malfunction in the radio system. One needs to average the data over 5 or 10 seconds - and that removes the spurious signal.


    Papers that discuss the analysis of these MRO tracking data (and those of other Mars orbiters) include


    Konopliv et al. (2016),

    Genova et al. (2016)


    The following paper discusses the analysis of the small data set of MRO radio occultation data, if that is your interest.  The author of this paper, David Hinson (SETI Institute, formerly Stanford Univ) can supply you with information about these data and where they were archived on the PDS.


    Hinson et al. (2014)


    Genova, A., et al., "Seasonal and static gravity field of Mars from MGS, Mars Odyssey and MRO radio science"

    Icarus, 2016, doi: http://dx.doi.org/10.1016/j.icarus.2016.02.050


    Konopliv, A., et al. "An improved JPL Mars gravity field and orientation from Mars orbiter and lander tracking data"

    Icarus, 2016, doi: http://dx.doi.org/10.1016/j.icarus.2016.02.052


    Hinson, D., et al. "Initial results from radio occultation measurements with the Mars Reconnaissance Orbiter: A nocturnal mixed layer in the tropics and comparisons with polar profiles from the Mars Climate Sounder"

    Icarus, 2014, doi: 10.1016/j.icarus.2014.09.019


    If you are looking for data from other missions (not the ones mentioned above), you can also ask Susan Slavney - who is the manager of the Geosciences Node.


    Susan Slavney [slavney@wunder.wustl.edu]


    Let me know if you have any other questions. Good luck.


    Best regards,

    Frank Lemoine


    (At the SLR workshop in Potsdam, Germany)

  7. New Mars Odyssey GRS data are included in Release 56. Raw data, Derived Neutron Data (DND) and Derived HEND Data (DHD) products cover the period October 1 through December 31, 2015. Averaged Neutron Data (AND) and Averaged HEND Data (AHD) products cover the period September 23, 2015, through January 4, 2016, Ls 45 to 75. The data are online at the PDS Geosciences Node at http://pds-geoscienc...dyssey/grs.html.

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