README28.TXT                WinOrbit 2.8                30 Nov 95

Read the file "README.TXT" first.  The information in this file
is duplicated in the Winorbit.hlp file.

Major Improvements in 2.8
-------------------------
Several major features have been added:
* A secondary satellite position and footprint can now be displayed 
on each of the maps.
* Mutual visibility prediction tables can now be printed. 
* A progress indicator is now displayed during long printouts, with an 
option to cancel if you get tired of waiting. 
* F1 now displays a more relevant starting point for help information 
for each window. 
* Station automation via AutoRun feature to run DOS or Windows 
programs at specified times relative to AOS for a specific 
satellite. 
* Doppler shift and path loss can now be displayed for uplink, 
downlink, or transponder delta frequency.


There is only one notable bug fix:
* The epoch was incorrectly updated when the UTC offset was not
   zero.  This has now been fixed (Satellite window).
Permanent color changes for the maps have been restored.  This
   feature got lost about v 2.6.

Major Improvements in 2.7
-------------------------
* Full state vector information (including velocity components) can 
now be displayed.  Import of state vector files is also possible. 
* Alternate satellite information databases such as "The Satellite 
Encyclopedia" may now be accessed directly.
* Squint angle calculation now included.  
* Calculation of spacecraft antenna and observer antenna pattern 
loss added to RF Info group in the Info Window. 
* Added a new window arrangement option: "Stack", in the Window Menu.
* The lines of latitude and longitude can now be turned off for 
creating cleaner maps for export.
* Improved timekeeping for real time mode on slow computers.  The 
program will now skip one or more intervals if it gets behind. 
* Orbit number (Rev) and Mean Anomaly (MA) now updated properly with 
SGP/SGP4 models.
* Updates of other Keplerian Elements with SGP/SGP4 models improved.
* Fixed crash when Sun or Moon selected while using non-USA date 
formats.
* Fixed bug that prevented proper element update after propagation to 
specified epoch.


Other New Items:

* A companion program for antenna control (using the Prairie Digital board) 
and radio doppler compensation (using serial or parallel ports or the 
Prairie Digital board) is available from the author.  "Some Assembly 
Required" !

Major Improvements in 2.6
-------------------------
* Glossary has finally been included.
* Immediate display of all stations in the QTH database 
   visible from a particular satellite for mutual visibility
   determination.
* Immediate display of all visible satellites, regardless of 
   whether they are being tracked on map.
* Sun and Moon may be tracked for antenna or receiver calibration.
   The algorithm is built-in, no keps are required.
* Latitude and longitude display and specification more flexible.
       Lat/long displays can be in decimal degrees or degrees, 
          minutes, seconds; and with choice of +/-, or 
          E/W notation.
       Choice of direction for positive longitude (E or W)
       Shift-click on a map adds a point to the QTH data base
       Ctrl-click on a map changes the observer location
       Lat/long and grid square of the point under the mouse 
          cursor can be displayed
* AOS for next pass now displayed on maps.
* Calculation of EQX, AOS, and Apogee/Perigee for tables improved 
   (more accurate, some speed up).
* Ephemeris output to an existing file is added at the end 
   ("append") instead of overwriting the previous information.
* Two-line element sets can be saved from the edited orbital 
   elements.
* User-provided maps may now be used for the background, for
   added display flexibility.
* Fixed bugs in Help:System Info and Colors} dialogs

Bug Fixes and changes in 2.5
----------------------------
- "Next Pass" now determined based on present UTC, not 
    local (CPU) clock time.
- Fixed the "resume without error" bug in Print Ephemeris
    when not printing to a file.
- If map (land/ocean) colors are changed, it is no longer
    necessary to "clear display" in each map after 
    restarting the program.
- Observer QTH now displays properly in the Main window.
- Help file displayed automatically if .INI file is not 
    current. 

Major Improvements in 2.4
-------------------------
- "View from Space" available (slow - not in real time).
- Sun and terminator line now move automatically in real
      time (if displayed)
- Fixed European (esp. German) number format bug (",").
- Print to File option for ephemerides. 

Major Improvements in 2.3
-------------------------
- Every satellite in file now available for printing (not 
      just the currently-tracked set).
- Function keys can be used for some common operations.
- Choice of 4 orbit-calculation algorithms.
- Display of additional observer locations for mutual
      visibility
- Grid locators for observer location entry (or calc from
      lat and long automatically)
- Display of solar position and terminator for eclipse 
      determination.
- Pop-up window to show elements, next pass, and other info.
- Additional ephemeris options including EQX, timeline.
- Print preferences now saved.
- Selectable colors for ocean and land on the map.
- Additional Items for DDE clients.
- Keplerian element computation features (propagate elements,
      change RAAN for delayed launch, etc.).

Other Changes in 2.3
--------------------
- Numerous bug fixes.  I hope the program will now work with
      ANY date and time format.
- Improved checking of data entry to avoid illegal values which
      might crash the program.
- Some rearrangement and renaming of menu items.
- More (and better ?) error messages.
- Map changed from 1- to 8-bit bitmap (hope this fixes the 32k-
      color display problem)

Improvements in 2.2
-------------------
- Added DDE interface for antenna-pointing systems.  See "Help".
- Extensively revised help file.
- Improved table printouts
- Minor changes to menus


Improvements in 2.1
-------------------
- User-specified colors for some map features
- Sidereal time offset now calculated from 4-parameter model
     instead of fixed value (errors reduced from 3 min to < 1 
     sec).
- Numerous changes to improve the user interface (menus, etc.)
- Setup menu now permits specifying an offset between computer
  clock and UTC (formerly required computer to be set to UTC)
- Improved handling of satellite files/lists and observer files/
     lists
- observer file LATLONG.QTH now included (list by ITU radio 
     prefix).
- Fixed bugs in resizing of map windows.
- Permit keeping just one map window visible
- European date format now works (formerly crashed on startup)

