Tom Wagner wrote: >Two questions: >(1) Does H-A consider atmospheric extinction when making >their flare magnitude predictions? Someone ... asked that question in 2001, and at that time Chris Peat replied -- if I understand correctly -- "No." http://satobs.org/seesat/Aug-2001/0491.html I don't find any update on that. Of course it's really tough, because the atmosphere can vary so much -- humidity, haze, dust, smoke, thin fog, etc. However, in the Iridflar 2.21 documentation Rob Matson wrote the following -- which I don't fully understand -- about Iridflar (and SkyMap): >Improved calculation of satellite lighting condition. Now >calculates lighting the same way that SkyMap does -- 15 km >or 20 km tangent height extinction (depending on season), >with 0.2 or 0.1 degrees of refraction respectively. Tom also asked: >(2) Does anyone know the lowest in the sky someone has >observed an Iridium flare? I don't know, but I've seen some pretty low ones. Just two nights ago (4:23:46 June 14 UTC), I (and Mike also I think) saw Iridium 40 (97-069C, 25041) at altitude 7, azimuth 255. It was predicted -1 by Iridflar, but I think it was actually fainter. However, the weather, though nice, was not pristine. Ed Cannon - ecannon@mail.utexas.edu - Austin, Texas, USA ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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