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Jul
2
awarded  Curious
Jun
11
comment How to calculate orientation of line segments using open source GIS?
Thank You, I translated it into MATLAB.
Jun
2
accepted Calculate actual Landsat image corner coordinates to derive azimuth (heading)
May
30
comment Estimating Landsat 7 azimuth (heading)
I finally find a solution, please see my answer at gis.stackexchange.com/questions/98425/….
May
30
answered Calculate actual Landsat image corner coordinates to derive azimuth (heading)
May
30
comment Calculate actual Landsat image corner coordinates to derive azimuth (heading)
I can derive the center of my image between its corners, but then how would I draw a line in it (in which direction?). I think using one of the side could anyway be a good proxy, but the best would be doing what you said, but it's tricky I suppose.
May
30
revised Calculate actual Landsat image corner coordinates to derive azimuth (heading)
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May
30
revised Calculate actual Landsat image corner coordinates to derive azimuth (heading)
added 414 characters in body
May
30
comment Calculate actual Landsat image corner coordinates to derive azimuth (heading)
According to the first link you posted, I got that the satellite passes above a specific location, always at the same hour ("same local mean solar time"), but the inclination of the satellite with respect to the polar orbit (saying, with respect a meridian), should be different as the satellite follows a "near-polar orbit". I am dealing with shadow casting on Earth, thus the satellite azimuth is very important to me. Finally, the S-shape is preserved, but should be slightly different than that of an exact polar orbit.
May
30
revised Calculate actual Landsat image corner coordinates to derive azimuth (heading)
added 256 characters in body
May
30
asked Calculate actual Landsat image corner coordinates to derive azimuth (heading)
May
30
comment How to calculate orientation of line segments using open source GIS?
Hey, I just found out I could really benefit from this code in my task. One thing, I have no idea which is the programming language it is written, could you please tell me so that I can use it? Is it java, javascript, c? thanks in advance!
May
23
revised Estimating Landsat 7 azimuth (heading)
added 911 characters in body
May
22
awarded  Popular Question
Apr
14
comment Estimating Landsat 7 azimuth (heading)
It seems John Parr Snyder created a new projection known as "Space Oblique Mercator" (SOM) to "continually map the Earth’s surface using Landsat data" (landsat.gsfc.nasa.gov/?p=3309), and that it is possible to project data through PROJ.4 (thanks to gis.stackexchange.com/questions/42432/…). I will try to come up with a result and will up date this page.
Apr
11
comment Estimating Landsat 7 azimuth (heading)
It only reads "The ETM+ design provides for a nadir-viewing, eight-band multispectral scanning radiometer capable of providing high-resolution image information of the Earth's surface when operated from Landsat 7, a 3 axis stabilized spacecraft located in a near polar, sunsynchronous and circular orbit at a 705 km nominal altitude, with an orbit inclination of 98.2 degrees." (Landsat7 Handbook). So I think it might be approximated as 8.2° anywhere since it doesn't tell much aboout this "near-polar orbit", would this be a good approximation?
Apr
10
comment Estimating Landsat 7 azimuth (heading)
I also know the scene center lat/long (they're equal to 46.036323 N and 10.456876 E, oh wonderful Italy), hope to understand how to use these data.
Apr
10
comment Estimating Landsat 7 azimuth (heading)
Thanks for the suggestion. I red carefully the Landsat Handbook, but I did not get how would I be able to estimate the sensor azimuth. For instance, how do You know that it is 8.2° at the equator? I know the corner coordinates (lat & long) of my scene. The image looks like a sort of isosceles trapezoid, with the major basis towards the North (as I would expect for the Northern Emisphere). It is also tilted differently from south to North (as I also would expect). Thanks in advance for any (other) help.
Apr
9
asked Estimating Landsat 7 azimuth (heading)
Mar
18
awarded  Popular Question