Skymap 6.3 release
Neil Clifford (neil@satellite.eu.org)
Wed, 3 Feb 1999 21:12:50 +0000 (GMT)
Rob Matson has released version 6.3 of Skymap (apologies to Rob for the
delay in distributing it). You can find it at:
ftp://ftp.satellite.eu.org/pub/sat/programs/ibmpc/sky63.zip
The other files are located in the same directory.
Over to Rob for a description:
Here's the new public-release version of SkyMap 6.3 (sky63.zip).
It's a one-for-one replacement for sky62.zip. sky62aux.zip
is still good, so no need to replace it.
There are a lot of changes from 6.2 to 6.3. As extracted from
SKY63.NEW, these are the main ones:
* Using the minus key (-) you can now zoom out beyond your current
field of view. When you zoom out past the size of the current
field, the crosshair and corner fiducials will change color
from green to red. When the fiducials are red, their positions
indicate the approximate size of the current field of view
relative to the future zoomed-out view. This feature allows
you to increase the size of the field without having to go back
into the menus.
* In addition to solar and lunar transits, you can now do conjunction
searches with planets, named stars or deep-space objects.
* Times can now be entered with colon delimiters or period
delimiters (e.g. 20:30 or 20.30). Allowing periods is helpful
since the shift key isn't needed, and there is a period on the
numeric keypad.
* Iridium flare calculations no longer performed for the failed
Iridiums 11 (#24842), 14 (#24836), 20 (#24871), 21 (#24873),
24 (#25105), 44 (#25078), 71 (#25320) and 79 (#25370).
(Iridium 27, and Iridium Sim1 and Sim2 were already excluded
in version 6.2).
* Modified autopoint function so that it always centers the field
of view on the culmination point and sets the map time to the
time of culmination. (Previously the map time would be set to
the time halfway between start-of-pass and end-of-pass. This
works for circular-orbit satellites that meet the lighting
constraints throughout a pass, but it fails badly for highly
eccentric orbits.)
* There is a hidden feature within SkyMap that will plot the star
magnitudes above every star. To activate it, open your .CFG file
with a text editor and change the "StarMag" parameter from off to
on. Magnitudes will be plotted dark gray without the decimal
point (e.g. 68 for 6.8).
* Discovered that Kepler's algorithm as coded in SGP4 can fail to
converge for highly eccentric objects such as Planet B, leading
to a fatal error. Algorithm bug fixed.
* Added a toggle to the All Satellite Menu that turns off warnings
of bad TLEs during an all satellite search. This is helpful when
using a large TLE file that has a lot of decayed objects in it.
Keyword in the configuration file is TLEWarn.
* Satellite visual magnitudes now displayed for sunlit satellites
when doing a lunar transit search. For lunar transits that aren't
sunlit, the satellite tracks are plotted blue.
* Modified track query output line to allow display of altitudes and
ranges greater than 100000 km.
* Bjoern Gimle discovered that erroneous line segments can appear
in the HPGL output (but not the screen output) when constellation
boundaries are turned on. Bug fixed.
* Added a minimum range filter to the All-Satellite search menu.
This feature allows you to filter out low, fast-moving satellites
when you are trying to identify a high-altitude satellite. Note:
only those portions of a track that are closer than the minimum
range will be filtered out. The portions that are far enough
away (and still meet the lighting constraints) will still be
plotted.
* Added a Show/Hide command to the Edit Satellite Menu. "-" is now
used (in conjunction with the working index) to hide specific
satellites' tracks. This way you can control which tracks get
displayed on your map without having to delete satellites from
your list. For example, if you have satellites 1-6 loaded in
your list, but you only want to see tracks for satellites 1 and
2 on your map, set the index to "3-6" and then use the "-" key
to hide them. (They'll be shown in the menu in dark blue). To
turn them back on, use the "+" key.
* Fixed a bug that can cause erroneous information to be displayed
for a track query (graphic command "T").
* Added display of orbit # (i.e. lifetime orbits) to orbital element
display screen. Since the two-line element set format supports
only 5 digits, extra logic was added to determine if the revolution
counter has "rolled over".
* Added a toggle (P) to the Map Attributes Menu that can be used to
turn off plotting of the dim planets: Pluto, Neptune and Uranus.
* Fixed a small bug that causes a daytime Iridium flare to have
an erroneous visual magnitude of 0.0 throughout a pass if all
MMAs happen to be pointed away from the sun.
* Added toggle (F8) in Lighting Constraint Menu to instruct
SkyMap to check if the sun is occulted by the moon as viewed
from the satellite. (This toggle should be set "Off" unless
you know a solar eclipse is occurring. The added overhead of
determining the moon's position will noticeably increase run
times.)
When F8 (Check for satellites in lunar umbra) is "On", program
determines if moon occults any portion of the sun as seen from
the satellite. If so, the satellite visual magnitude is adjusted
to account for the fraction of the sun occulted.
If the sun is more than 50% occulted, the satellite track color
is set to dark blue. (This is a slightly darker blue than the
blue used for tracks when the earth limb is blocking part of the
sun.) If the sun is more than 90% occulted, the satellite track
color is set to dark purple (a darker purple than that used for
tracks dimmer than the satellite magnitude limit).
--
Neil Clifford
<neil@satellite.eu.org>