I am using GAOFEN-1/GAOFEN-2/ZIYUAN-012C to simulate remote sensing coverage. What sun elevation angle constraints should I set for sensors?
Qianqian Wu
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The sun elevation is dependent on acquisition time (e.g. late morning for many satellites), day of the year and latitude. All you need is those 3 values and then you can estimate the range of normal elevation for a given site,
Hi, it depends on your necessity. The relative position Sun-Target-Satellite affects the quality of the image and enhance different features. For example, for intelligence activities it's usually better to observe the target laterally with the sun that projects shadows on the scene allowing the interpreter to better investigate the image. On the contrary, a nadir position of the Sun can generate lots of brights spots on your image (sensor saturation). For this reason most of the optical sensors are not employed with SSO at 12:00am-12:00pm. Moreover, it's worth noting that the higher the sun elevation angle the less should be the integration time of the image since the sun power is higher. According to my experience typical range lies from 10-15° to 85-90°.
That's dependes of your proyect. High sun elevation is much appropiate for spectral analysis because objects on surface are well iluminated and there are nearly a lack of shadows that interfiere with the recording of spectral signatures. Medium to low sun elevation is much more appropiate for the interpretation of surface morphology as Alessandro Panico stated.
Cheers Gabriel
Thanks. I have solved the problem under your help. Gabriel Asato Alessandro Panico Ammar S.Ismael Sylvain G Leblanc Aahed Alhamamy
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