palmer@sfu.ca (Leigh Palmer) writes: > Subject: Re: Mir seen at -0.8 degree? > To: tomnagy@nauticom.net (tom) > At 8:41 AM 12/29/96, tom wrote: > >What elevation do you have set for your location? > and for the elevation of the plains east of the Front Range > which presumably lie on your horizon? I understand you are > observing from Colorado. ... > [Ron Lee writes:] > >I am using the term "elevation" to represent vertical > >angle from the horizon, where the local true horizon > >is 0 degrees and the zenith (overhead) is 90 deg. > As I mentioned, that is an unusual meaning. The > conventional coordinates are altitude and azimuth. This is indeed confusing. Some blame goes to the aerospace industry for having taken it upon itself to reuse, in totally nonsensical ways, two long-existing terms with well-established meanings, namely, altitude and elevation. They should be thoroughly thrashed with a wet noodle. And they should stop. How many people will have to die before they decide to rectify their mistakes? Properly, elevation is the distance above mean sea level (MSL) in meter. (SI has dropped plurals, presumably for the convenience of non-native speakers). Altitude is the complement of the zenith distance. Zenith distance is the angle from the zenith. Conventionally, altitude is measured in degrees (of arc), with the zenith at 90 and the geometrical horizon at 0. Vertical angle is something different. See my earlier post (from late summer?) in the SeeSat-L archive. Whatever altitude for the true horizon you determine, I would expect it to be quite low, because I recall seeing a very decent green flash at Sun rise, looking East from a ninth or tenth floor hotel window somewhere near Stapleton Airport in Denver, Colorado, USA. BTW, by definition, Sun rise (at sea level) occurs when the geocentric zenith distance of (the center of) the Sun is 90 degrees 50 minutes. Jay Respler wrote: > All sats have NAMES in addition to #. Yes, but these names can be very troublesome indeed. This is one reason I always try to give all 3; catalog number, COSPAR id and vulgar name. 'Course I still haven't seen agreement about what format should be used for the COSPAR id, even among those who like it. > QUICKSAT ... > QUICKSAT ... > QUICKSAT Atta'boy, Jay. It certainly seems worth the trouble to me. It also seems that an ephemeris server to run it, together with a team of computors and updaters of orbits, would make a great deal of sense. It is my perception that much of the remaining "activation energy barrier" from Molczan's Law lies in the difficulty of elset maintenance. The team might consist of Ted Molczan, Mike McCants, TS Kelso, Bj"orn Gimle, Alan Pickup, Pierre Nierinck, Rainer Kracht, Ron Dantowitz, (myself? in this crowd, despite my extensive experience with Mir and shuttles, I'm definitely a junior member) and other trusted computors (my apologies to anyone I've forgotten). If it is thought necessary for performance reasons to limit access, my guess is that a public server allowing one day's worth of successful requests per day per location, each request being for a single evening or morning (or a 6-hour night, near the poles) would be quite serviceable. People with special requirements could be authorized to make particularly deep or lengthy searches. Those who are regular (or irregular, for that matter) contributors to SeeSat-L could probably be authorized without further qualification. If such a server existed, perhaps NASA and the RSA could be persuaded to update it directly, particularly for shuttle maneuvers and Mir reboosts. Wouldn't that be a treat! (Mike, do you recognize here any threads from my previous email?) Indeed, the server might be intelligent enough to recognize regular requests and pre-compute them in its spare time, thus avoiding CPU bottlenecks. Ted Molczan writes: > >of course, there's always > >3) There's nothing to explain. The pattern didn't exist before about ten > > years ago, not that many satellites have flown subsequently, > > and the pre-solstice "pattern" is most likely a fluke of small- > > sample statistics. > I like that explanation the best. Normally I am on the side of those whose rant and rave about small sample size. But I am surprised (what is wrong with the stupid Americans spelling this word with "ised"?) to read of your opinion, because the pattern has been established so long. I've read here recently about some nice observations. Congratulations. Cheers. Walter Nissen dk058@cleveland.freenet.edu resident, Pale Blue Dot --- Carl Sagan, 1934-1996, explained in a most compelling way to millions of students why what they are learning in science classes is so surpassingly important; important to students, to people, to our species.