It's a terrible error for any GPS or map (if arcsecond -or even arcminute- accuracy appears possible), and there is no (known) reference system that has such an offset ! The error is about 4 km N-S, 7 km E-W, or about 0.5 degree at 800 km range. That is usually fully acceptable if you report an UNID, or an obs where the elset is minutes in error because it is a satellite near decay, or you recover a "lost" classified satellite after a long period in daylight/shadow. It is also sufficient for an analysis and prediction of flashes from a spinning satellite - not for an operational Iridium where pointing accuracy is much higher and necessary for accurate prediction. For a geosynch (flasher?) it would give only 0.01 degree error - quite acceptable even for a positional obs, more than enough for flash prediction. ----- Original Message ----- From: "Curt Porter" > I wonder where I really am. My LAT/Long is > 36 12 34N 86 42 13W via the U.S.G.S. quadrangle charts > but get different figure with a GPS. Could the charts be wrong? > Or maybe the man had a cheap GPS? > > Changing to decimals: > > chart GPS > 36.2094N 36.166N > 86.7036W 86.784W > > If I were to post data points for satobs I realise this > would throw the calculations off. Is it a significant error? ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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