The first file in the 1-minute and 10-second tabs, while dated in the past, cover 21 vs. 10 days into the future from that date. http://www-calipso.larc.nasa.gov/tools/overpass/coords/CPSO_1minute_GT_2009_02_18.txt Maybe because the current problem, the 10-s files are outdated. I can give you formulae for great circle interpolation between 1-minute points, but that would be overkill if the 10-s file is published when the laser is on. Then you can do linear interpolation, unless you live in near-arctic areas. Heavens-Above can give you ground tracks, but not accurate enough for Calipso (and I don't see the point of using ground tracks instead of star tracks for aother satellites). You can use Google Earth and load a .kml file built from the CPSO file to show a ground track. A stripped-down sample built from the file above: <?xml version="1.0" encoding="UTF-8"?> <kml xmlns="http://earth.google.com/kml/2.2"> <Document> <name>2008-11-18 Calipso.kml</name> <comment> 14 Mar 2009 09:32:00.000 37.0876 -109.4213 708.5265 14 Mar 2009 09:33:00.000 33.4919 -110.4553 707.8640 14 Mar 2009 09:34:00.000 29.8895 -111.4272 707.2730 14 Mar 2009 09:35:00.000 26.2814 -112.3489 706.7686 </comment> <Placemark><name>Calipso</name> <TimeStamp><when>2009-03-14T09:32:00-07:00</when></TimeStamp> <LookAt><longitude>-110</longitude><latitude>32</latitude><altitude>0</altitude> <range>272000</range><tilt>0</tilt><heading>0</heading></LookAt> <LineString><extrude>1</extrude> <tessellate>1</tessellate><coordinates> -109.4213,37.0876,10 -110.4553,33.4919,10 -111.4272,29.8895,10 -112.3489,26.2814,10 </coordinates></LineString></Placemark> </Document></kml> ----- Original Message ----- From: "Paul Bridges" <bridges_paul@yahoo.com> To: <seesat-l@satobs.org> Sent: Friday, February 27, 2009 6:30 PM Subject: Calipso questions > Amateur/Lurker here in California. I have some Calipso passes over the > next few months and would like to try to observe/photograph the green > laser. I see that the laser is down for most of Mar/Apr due to a leak, but > I have good passes in May. I would be appreciative if someone could clear > up some of these questions... > > 1. I normally usually use Heavens-Above and HeavenSat to spot ISS, STS, > and Iridiums. Is there a better tool (using Windows) for making ground > tracks? H-Above provides little detail. SeeSat archives mention > http://www-calipso.larc.nasa.gov/tools/overpass/coords, but this appears > to be only historical data, and I don't know how to make a ground track > from it. > 2. I see mentions of "orbit raise" and "drag make-up maneuver". What is > the difference? Is it safe to assume they only affect timing by a few > seconds and not the ground track? > 3. Since the beam width on ground is only 70 meters, how do I fine tune or > verify position? How would I generate coordinates for use with GPS? > > Thanks in advance > > Paul B. > > ------------------------------------------------------------------------- > Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: > http://www.satobs.org/seesat/seesatindex.html > ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Sat Feb 28 2009 - 09:31:11 UTC