4 ms·
Exactly! I'm working on some stuff now to exploit this very effect, the small time difference in the bands can be used to find velocities of moving objects.
by amcoastal 5y ago
Exactly! I'm working on some stuff now to exploit this very effect, the small time difference in the bands can be used to find velocities of moving objects.
- samhw 5y agoThis is incredibly cool. What's the application (if it's possible to obscure whatever details you don't want to divulge)?
- amcoastal 5y agoIts coastal physics work, you can infer near shore conditions by watching wave propagation.
- geoduck14 5y agoSo... like where submarines are based on water disturbances?
- amcoastal 5y agoThat's not what I'm doing but it seems possible you could watch refraction patterns and tell that there are submerged objects, but you'd need to know the water depth without that object there, as there'd be no great way to tell if the object is a submarine or a pile of sand. Also, most of these satellites pass over fairly rarely so wouldn't be super useful for tracking things that move. I'm mostly interested in finding the piles of sand :)
- tech_timc 5y agoThe same effect can be used to estimate cloud heights, and to identify aircraft flying above clouds. Parallax based Cloud Detection for Sentinel-2 Analysis Ready Data Generation https://www.researchgate.net/publication/332999809_Parallax_based_Cloud_Detection_for_Sentinel-2_Analysis_Ready_Data_Generation https://www.researchgate.net/publication/332999809_Parallax_... Aircraft Detection above Clouds by Sentinel-2 MSI Parallax https://www.mdpi.com/2072-4292/13/15/3016 https://www.mdpi.com/2072-4292/13/15/3016
- magicroot75 5y agoIs this at all analogous to how we used red/blue shift to determine the speed at which astronomical objects are moving towards/away from us?
- oivey 5y agoNo, that’s the Doppler effect. This is a time delay between when different colors were captured.
- magicroot75 5y agoAh gotcha. Makes sense. Thanks!