"Balcewicz, Joseph F" wrote: > Has anyone reported seeing a GPS (Navstar) satellite with the unaided eye? > > What magnitude might they be? > I figure magnitude 10-12. Satellite situation report says they have radar cross sections of 10-100, which is higher than many LEO satellites, but then they are also 20x farther out than LEOs. I've constructed a little standard curve of magnitude vs rcs/d^2 function and (given all the simplifications I've made) come up with a rule of thumb of a magnitude of 7.3 for a satellite with an rcs of 1 at a distance of 1000 km. (Yes, I know about paint, shape, angle, diffuse and specular reflectance (thanks Mike!) - I just want a ballpark figure). So a GPS with rcs of 20 and a distance of 20,000 km should be 1/20th as bright as the standard, or 3+ orders of magnitude dimmer. Somewhere around magnitude 10-11. I *think* that's close? I've been watching for satellites with especially low rcs values (the tethered picosat has one of 0.0001!) to see how far down my 12.5" scope can observed (it can't see the tethered picosat, but it did get the CSL-04 99057AU fragment at 1100 km and rcs=0.18 last night). I noticed in the SSR that geosynch Galaxy 5 has a rcs of 760 (suggesting magnitude 7-8) and Glonass 36, the Russian GPS counterpart, has a rcs of 555. Could these be right? Wayne ----------------------------------------------------------------- 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 May 31 2000 - 10:32:58 PDT