I'm starting a new project and it's the first time I work with satellite imagery. Would anyone care to explain how to obtain the azimuth angle from the CORNER_ X/Y or the latitude/longitude data in the MTL file? I've seen it in other posts and I still don't get an idea on how to do it!
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1Welcome to GIS SE! If you have seen this in another post, then I recommend that you edit your Question to include a link to it, and expand upon where whatever instructions it gave started to lose you.– PolyGeo ♦Commented May 12, 2014 at 23:50
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1 Answer
Two directly related questions are Landsat Observation Zenith and Azimuth Angles and Estimating Landsat 7 azimuth (heading). However, they don't say exactly how to determine azimuth from two corner coordinates of a scene.
Assuming you do have the long-lat of two eastern or western corners, I believe the problem is now "simply" how to determine the azimuth given a pair of geographic coordinates. This is often called the inverse geodetic problem (or reverse geodetic problem). Two questions on that are Geodesic measurements for short distances throughout US? and Variation of algorithms to find point from another point with bearing and distance. They go into some of the math/theory.
You may just need an online geodetic calculator, such as Movable-Type's LatLong, the GeographicLib's GeodSolve or the Australian Vincenty_Inverse.
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For an approximate solution (less accurate in higher latitudes), you can just treat the lon-lat as though they were planar coords and use the simple plane trigonometry function, often called atan2().– Martin FCommented May 13, 2014 at 14:57