What's New in CASPER Version 4.0

    Several additions and changes have been made to CASPER in Version 4.0.  Some changes were introduced in CASPER Version 3.6 but never fully documented.  This page lists the main changes to CASPER.  It is worth reviewing if you are familiar with previous versions of CASPER.  For more detailed information on how to use these new functions, consult the on-line CASPER help accessible via help buttons.
     

  • IVP versions of modules: CASPER 4.0 includes IVP simulation for GENMOSAB, GENMOSCD, GENMOSR, MAPSPA, and TARGET.  CASPER 3.6 included GENMOSAB_IVP and that implementation has been improved in 4.0.  Non-IVP versions of these modules are included for backwards compatibility only.  You can make an inertial observation with the IVP modules, and it is strongly recommended that only the IVP versions of these modules be used for new observation designs.
  • Improved link to PDT: All IVP modules listed above can be saved as Request Working Files (RWF) which can be read by PDT.  The RWF can be edited within PDT and run in PDT to check constraints and to complete or refine the observation design.  Only one observation can be saved to an RWF in this manner at a time.  A separate RWF is required for each observation.
  • Improved C kernel data viewing.  The C kernel viewer has been improved.  When plotting footprints from a C kernel, it is now possible to use the Pointing/Module Info tool (under Utilities in the Target tool) to get detailed pointing information for each selected footprint.  It is now also possible to have CASPER plot footprints for each record within the C kernel rather than only at equally spaced time intervals.  Large amounts of pointing data can be saved to an IDL save file from the C kernel viewer when plotting the display in Target is not practical.  This pointing data can also be plotted directly from within the C kernel viewer tool.  So, for example, you can get a plot of phase angle as a function of time from data in a C kernel.
  • LIMBDRIFT deleted: this module is essentially just a special case of GENMOSCD.  Rather than maintain LIMBDRIFT and update it to be consistent with the other improved modules, it has been deleted.
  • Improved turn model: CASPER now uses a turn time model that more closely simulates what the spacecraft can actually do.  Turn times should be reasonably accurate, but PDT should be used for detailed checking of observation times.
  • Improved module parameter control: it is now possible to directly enter most module parameters for GENMOSAB, GENMOSCD, GENMOSR, GENMOSP, and MAPSPA.  This includes setting the scan rate which was previously locked into the maximum possible rate.
  • It is now possible to save a SkyMap plot as a PostScript file.
  • New kernels provided with CASPER version 4.0 include a new version of the T18-5 tour at Saturn.  Unfortunately this kernel reverts to identifying the spacecraft as "CASSINI SIMULATION".  You will need to be sure to specify CASSINI SIM as your observer when using this new file.
  • Spacecraft trajectory time tick marks can be switched on in the 3-D View tool.
  • A shortcut button has been added for deleting the last module in the session.
  • A tool has been added which displays an annulus of space centered on the plane which is 90 degrees away from the RAM direction.
  • Because the GIF file format is now proprietary, IDL is no longer supporting the capability to read and write GIFs beginning with IDL Version 5.4.  For compatibility, CASPER no longer allows the user to save target plots as GIFs.  The PNG (Portable Network Graphics) format is used instead.  PostScript and TIFF continue to be supported.