Matson, Robert wrote: > Jonathan was inquiring about how to approximate a satellite's > visual magnitude when only its RCS is given. As others have > eluded, you can't really. RCS is very sensitive to the > geometry of the object in question. Establishing theoretical mathematical function between the effective area (ie. aerodynamic parameter) and observable magnitude is impossible. The situation is more complicated as stated in cited e-mail, because there is at least one more free parameter in question, namely albedo of the object (ie. reflectivity) due to the different materials used on its surface (cf. eg. problems of estimating diameters of small Solar system bodies). For ordinary materials albedo may vary between 0.95 (polished surface) to cca. 0.4 and for space debris it is practically impossibte even to quess its value. The only way is the mentioned one, ie. empirical formula obtained by statistical evaluation of enormous amout of observational data. Thanks, Robesrt, for doing that. > so don't know what the 1-sigma error > bars were on that value. I think this (statistical) dispersion should be rather big. Due to the -------- Mgr. Antonin Vitek, CSc. Office: Main Library, Academy of Sciences of the Czech Republic Narodni 3, CZ-11522 Praha 1 - Phone: +420(2)21403255, fax +420(2)24240611 Home: Kytin 127, CZ-25210 Mnisek p. B., Czech Republic Phone: +420(305)592865 - Coord.: 14.2194 deg E, 49.8488 deg N, 442 m ASL My satellite home page: http://www.lib.cas.cz/www/space.40/index.html ----------------------------------------------------------------- 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 : Tue May 22 2001 - 00:00:19 PDT