Russ Bessom wrote: > > Greetings all, > I know this is off topic but I didn't know what other group to pose this > question...What is the equivalent of Arc minutes to Km's or Degrees to > Km's. As Tony Beresford replied, the way to do this accurately is using radians. However, the nearly equivalent "one in 60" rule of thumb is often useful: An object of unit width subtends one degree at a distance of about 60 units. E.g., if two satellites are 1.5° apart at a range of 600km then their separation perpendicular to the line of sight will be pretty close to 15 km. For distances on the Earth's surface and angles subtended at the centre of the Earth: 1 arc minute subtends about 1 nautical mile (that's where the nautical mile originally came from). An international nautical mile is now 1852 metres exactly which is about 1.15 statute miles. 1° therefore shows up on the surface as 60 NM, 69 statute miles or 111 km, roughly. Ed Davies. ----------------------------------------------------------------- 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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