PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = PUB DATE YYYY-MM-DD XXXPENDINGXXX INTERCHANGE_FORMAT = ASCII NOTE = "Description of the EXTRAS directory" END_OBJECT = TEXT END EXTRAS Directory Contents The EXTRAS directory contains additional files beyond the scope of the PDS archive requirements. The following files are found in the EXTRAS directory: EXTRINFO.TXT - The file you are now reading mer1.sav - An IDL save file that contains all the data in file MER1PROFILE.TAB from the DATA/ directory, plus some additional data. Created by makepdstable.pro. See makepdstable.pro to understand what each variable in this IDL save file is. mer2.sav - An IDL save file that contains all the data in file MER2PROFILE.TAB from the DATA/ directory, plus some additional data. Created by makepdstable.pro. See makepdstable.pro to understand what each variable in this IDL save file is. suppinfo_README.txt - README file that was published as part of the supplementary information for [WITHERS&SMITH2006A]. suppinfo_mer1table.dat - Data file containing results from the MER-1 reconstruction that was published as part of the supplementary information for [WITHERS&SMITH2006A]. suppinfo_mer2table.dat - Data file containing results from the MER-2 reconstruction that was published as part of the supplementary information for [WITHERS&SMITH2006A]. meraltedlandtimes.pro - IDL procedure used to find the alternative entry states described in DATASET.CAT and to convert SCLK times into UTC times for START_TIME and STOP_TIME in MER1PROFILES.LBL and MER2PROFILES.LBL. Requires SPICE software. The EXTRAS directory also contains a subdirectory, CODE. The CODE directory contains all the programs used to generate MER1PROFILES.TAB and MER2PROFILES.TAB. These programs are written in IDL. All users of this dataset can understand, but not run, these programs by studying any of the many books published about this computer language. These programs are provided so that users of this dataset can fully understand exactly how these data products were produced. These programs may also be useful to some users in other ways. Users who possess the free IDL Virtual Machine software or who possess a non-free licensed version of IDL can edit and run these programs to better understand the sensitivity of the derived data products to the assumptions discussed in DATASET.CAT. Such users will need to manually edit some of the directory names used in these programs to names suitable for their computer systems. These programs have been developed over several years. They contain comments, but some of the comments are out of date. The following files are found in the CODE directory: 1TRANSFORMED.TAB From PDS archive MERIMU_1001 [KASSETAL2004]. 2TRANSFORMED.TAB From PDS archive MERIMU_1001 [KASSETAL2004]. derivs.pro Provides velocity and acceleration. Used by Runge-Kutta integration procedure in recon_traj.pro. get_acc.pro Provides accelerations in Mars-fixed frame. Used by derivs.pro, recon_traj.pro. get_altlatlon.pro Converts position from cartesian frame to spherical polar frame. Used by derivs.pro, recon_traj.pro, set_initial.pro. get_cd.pro Provides CA, CN and alpha. Used by recon_atm.pro. get_cdx.pro Provides CA, CN and alpha. Used by hiz.pro. get_entry_state.pro Converts entry state into cartesian frame. Used by recon_traj.pro. get_grav.pro Provides acceleration due to gravity in cartesian frame. Used by get_acc.pro. get_sr0.pro Converts radial distance to landing site into a string. Used by maketable.pro. hiz.pro Determines high altitude atmospheric structure as described in [WITHERS&SMITH2006B]. Output from this program is not archived. I do not recall why hiz.pro uses get_cdx.pro, not get_cd.pro. Both get_cd.pro and get_cdx.pro access the same basic aerodynamic database. The main difference appears to be that get_cdx.pro can introduce uncertainties into values of CA. makeicarustable.pro Combines many output files from recon_traj.pro and recon_atm.pro into one file. Used to generate supplementary information files that accompanied [WITHERS&SMITH2006A]. makepdstable.pro Combines many output files from recon_traj.pro and recon_atm.pro into one file. Used to generate the datasets contained in MER1PROFILES.TAB and MER2PROFILES.TAB. marsprops.pro Creates common block of properties related to Mars. mer1_pds.dat Contains data that has originated in 1TRANSFORMED.TAB and has been processed. Created by read_pds.pro. Used by recon_traj.pro mer2_pds.dat Contains data that has originated in 2TRANSFORMED.TAB and has been processed. Created by read_pds.pro. Used by recon_traj.pro. output/ Directory where output from recon_traj.pro and recon_atm.pro are stored. Currently empty. read_pds.pro Ingests data from either 1TRANSFORMED.TAB or 2TRANSFORMED.TAB, processes data and outputs data to either mer1_pds.dat or mer2_pds.dat. recon_atm.pro Uses output from recon_traj.pro to reconstruct atmospheric structure. recon_traj.pro Uses output from read_pds.pro to reconstruct trajectory. sctprops.pro Creates common block of properties related to either spacecraft. set_initial.pro Enters the initial position and velocity into the appropriate arrays. Used by recon_traj.pro. setup_arrays.pro Create many arrays used by recon_traj.pro. Used by recon_traj.pro. update_arrays.pro Enters the current position and velocity into the appropriate arrays. Used by recon_traj.pro. The aerodynamic database is an important part of the atmospheric structure reconstruction. A common block containing the aerodynamic database is created in sctprops.pro. The aerodynamic database has been published in graphical form in [SCHOENENBERGERETAL2005B]. Several different flight regimes are encompassed by the aerodynamic database: free molecular flow, transitional flow, hypersonic continuum flow, and supersonic continuum flow. Data for the free molecular flow and transitional flow regimes were taken from Figure 6 of [SCHOENENBERGERETAL2005B] and manually transcribed into sctprops.pro. The hypersonic continuum and supersonic continuum portions of the aerodynamic database were provided to Paul Withers by Mark Schoenenberger and Prasun Desai. According to a personal communication from Desai to Withers, these portions of the aerodynamic database cannot be made publicly available in a tabular format. Therefore these values have been set to zero in sctprops.pro. Users who wish to run these IDL programs will have to manually extract values from Figure 7 of [SCHOENENBERGERETAL2005B] and enter these values into sctprops.pro. These IDL programs should be run as follows: Make any necessary edits to the files, especially marsprops.pro and sctprops.pro Start IDL Run marsprops.pro Run sctprops.pro Run read_pds.pro Run recon_traj.pro Run recon_atm.pro Run hiz.pro Exit IDL