> DeHBeaver0@aol.com wrote: > >>When I joined this list, I figured it was all about 'just' >>watching the satellites. But I frequently get these emails >>from all of you with "elsets" or "OBS". >>And the letters contain all numbers with + and - marks. >>Could someone help me out here?! What do they mean, and >>how do I interpret them? "Elsets" are element sets, also known as two-line elements or simply TLE. Here's an example: Mir Complex 1 16609U 86017A 00032.55381491 .00040933 11633-4 16578-3 0 3075 2 16609 51.6516 240.6892 0016841 293.2056 66.7169 15.86997725797610 For info on what the numbers mean see: http://www2.satellite.eu.org/element.html and http://celestrak.com/columns/v04n03/index.html Also see the home page of the first one above for much more about visual satellite observing: http://www2.satellite.eu.org/satintro.html "OBS" stands for Observation. Some of the OBS emails you see are timings where each line indicates a satellite's position at a given point in time. These are in interactive orbit determination format (or IOD format). See http://freeside.fc.net/~mikem/iodformat.html for an explanation. Other emails you may see could be flash timings for tumbling satellites in PPAS format (photometric periods of artificial satellites). See sections 5 & 6 of ftp://ftp.fc.net/pub/users/mikem/ppas8.txt The OBS in IOD format probably won't help you much, they are mostly used to create or update TLEs. The TLEs themselves, however, can be helpful (in fact, are necessary) if you want to make your own satellite predictions. You can obtain software allowing you to make your own predictions from http://www2.satellite.eu.org/orbsoft.html Depending on the satellite orbit TLEs are only good for a few days to a couple weeks so you need to constantly obtain updated TLEs. A good place to get TLEs is from http://www.fc.net/~mikem/tle.html and download the mccants.zip file (contains TLEs for about 1500 satellites). Or, for a smaller list (about 120 satellites), go to http://www.wingar.demon.co.uk/satevo/tle/ and download the select.zip file. >>Also- Some [brighter?] satellites you follow, such as >>USA 129 or ETS-6: Where do you get the info for these? Not sure what info you are looking for, but some info about the actual spacecraft can be found at http://www.friends-partners.org/~mwade/spaceflt.htm and most (unclassified) missions have their own web pages. The above mentioned links in no way exhausts the amount of data available on the web about these topics. Many other valuable resources are maintained by members of the SeeSat-L list and are often referenced at the bottom of their emails. Ralph McConahy 34.8829N 117.0064W 670m ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Wed Feb 02 2000 - 15:13:39 PST