Will satellite imagery be able to see the backs of big animals such as lions, tigers, elephants, horses or zebras from space when they venture out in the open? I've not been able to find satellite imagery that captures such animals in the open.
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Yes, but it requires exceptional resolution. The GeoEye-1 satellite has 0.41 m resolution, and it has been used to count animals. Here you can see a picture it took of wildebeests:
Image Credit: ITC The black and white image is the satellite image (though GeoEye-1 can do color imagery as well in 1.65 m resolution). The tiny dots peppered across the park are wildebeests. |
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This is technically possible to see big animals, but we are still far to identify them without context information. For commercial satellites, the highest spatial resolution is 31 cm at nadir view (worldview-3), but only in the panchromatic band. For colors, the resolution is still very good (1m24) but only large animals are visible. Only animals with a high contrast are therefore visible (easier to see a horse than a lion) BUT you can also use their shadows for a better detection (helps to identify a giraf). One very usefull feature to detect animals is the use of thermal infrared. However, this is currently not possible with commerial satellites due to the coarser spatial resolution in this wavelength. To conclude, even if there are som studie are some studies in open savannah or artic areas where spatial remote sensing is applied to animal counting, it is still very difficult to differentiate the species and even counting is sometimes difficult (like you must look at the spots that moved, but you cannot tell that any spot is an animal). However, given the trends in spatial resolution of commercial satellites (which is no more legally limited to 50cm), one can expect 10-25 cm in a near future, which would look like the cows below (from an aerial photo at 25 cm in true colors, satellites are not (yet) at this resolution. And of course, I am only mentioning commercial satellites for the currently available resolution).
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