SkyMap 6.0

ROB MATSON (ROBERT.D.MATSON@cpmx.saic.com)
8 Jan 1998 15:24:06 -0800

Hello all,

Neil Clifford has kindly made SkyMap version 6.0 available at the
oxford site:

ftp://ftp.satellite.eu.org/pub/sat/programs/ibmpc/

This is a major upgrade from version 5.11.  There are six archives:

sky60.zip
sky60aux.zip
hip8.zip
hip8idx.zip
hip9.zip
hip9idx.zip

Previous users do not need to download sky60aux.zip since none of its
files have changed in the last two years.  HIP8.ZIP contains the new
Hipparcos star catalogue to magnitude 8.49.  It contains 61321 stars,
and is a vast improvement over the SAO files (MAG6.DAT and MAG65.DAT)
in terms of number of stars, astrometric accuracy, and visual magnitude
accuracy.

If you need stars magnitude 8.50 and dimmer, you'll want to
also download HIP9.ZIP which has an additional 56897 stars down to
magnitude 14.  (Note:  very few stars in this file are dimmer than 11th
magnitude.  The combination of HIP8 and HIP9 is fairly complete to
about magnitude 9.)

HIP8IDX.ZIP contains two index files for HIP8 -- one for Henry Draper
catalogue numbers, and one for Hipparcos catalogue numbers.
HIP9IDX.ZIP contains the corresponding files for HIP9.

Besides the improvement in the star catalogue, there have been a
lot of functional upgrades in 6.0.  Many of these were suggested by
long time users.  Changes include:

1.  Graphical satellite track query feature added.  Once a map is
     plotted, use arrow keys to point to the track of interest and then
     type the letter T (for track).  The top of the screen will display
     the satellite's name, international designator, the time of the
     tick mark on the track closest to the cursor, the altitude and
     range in kilometers, the phase angle (measured from satellite to
     observer to sun), and the predicted visual magnitude.

2.   A "night-friendly" toggle has been added to the Map Attributes
     Menu.  Command "S" controls a toggle between regular SkyMap
     menus and dark-adapted menus that use dimmer colors (predominantly
     red).  Some of the features of the dark-adapted plots are also
     more night friendly (e.g. cyan grid is dark gray, stars and track
     labels are gray, border is red).  (Feature requested by Ed Light
     and Craig Cholar.)

3.   Report file is now sorted chronologically by culmination date/time
     of pass, or transit date and time if searching for transits.
     (Feature requested by Robert Sheaffer, Darwin Teague et al.)

4.   Report file dates are now in YY/MM/DD format.

5.   Added mirror-image view capability to Map Configuration Menu.
     The command is "V", which toggles between normal view and mirror
     view.  This feature can be used to compare SkyMap output with the
     left-right reversed images of most telescopes.

6.   If your star file is set to HIP8.DAT, SkyMap will automatically look
     for HIP9.DAT if your visual magnitude limit is dimmer than 8.49.

7.   Star query function now displays both the star's Hipparcos (HP)
     catalogue number and its Henry Draper (HD) catalogue number (if
     it has one).  This information is stored in files with extension .HP
     and .HD, respectively.  For example, the Henry Draper catalogue
     numbers for all stars brighter than magnitude 8.50 are stored in
     HIP8.HD.)  If using one of the old SAO star files, the star query
     function displays the SAO catalogue number instead of the HP #.

8.   Can now point to a star by entering its six-digit Henry Draper
     catalogue number.  Enter F2 from the Map Attributes Menu, and
     when prompted, enter "HD" and the 6-digit Henry Draper catalogue
     number.  (The "HD" is required to distinguish between HP/SAO
     catalogue numbers.)  .

9.  Similar to how SkyMap handled pointing to a star using its SAO #,
     the map field of view can be centered on a Hipparcos star by
     entering either its HP # or HD (Henry Draper catalogue) #.

10. Satellite tracks can now be labeled with either their Norad #,
     international designator (e.g. 86017A for Mir), name, or nothing
     at all.  Choice is controlled by a 4-way toggle using command
     "T" in the Satellite Menu.

11. The range of arrow key map recentering has been extended so that
     the center crosshair no longer has to remain on the map -- just
     one of the four corner braces.  (Bjoern Gimle request)

12. SkyMap now checks for write permission before updating the
     temporary configuration file.  This prevents the loss of all your
     parameters if this file happens to be in use by another program.

13. Satellite International ID added to satellite element display page.
     Display page is now shown BEFORE the user has to decide if it's
     the satellite he wants.  "X" command added to display page to
     skip unwanted satellites that are found.

14. Days-since-epoch and an estimate of along-track time uncertainty
     are now reported when loading satellite elements.  The along-track
     uncertainty is linearly related to the uncertainty in the mean
     motion of acceleration -- a value the user can select.  Keyword
     is "DragUnc".  For example, if DragUnc = 25., then SkyMap assumes
     the uncertainty in the mean motion of acceration is 25%.  DragUnc
     only affects the calculation of along-track time uncertainty.

15. When loading new satellite elements, there are now options for
     changing the satellite's mean motion of acceleration, mean motion
     2nd derivative, and SGP4 pseudo-drag values.

16. Right ascension and azimuth grid lines are no longer extended all
     the way to the poles and zenith/nadir respectively.  This makes
     for a "cleaner" appearance.

17. A toggle has been added to the All-File Search Menu to give the
     user the option of not being warned about overwriting the report
     file.  Command is "W".

Thank you all for you patience in waiting for the new version!

Best wishes,

Rob