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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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It is technically possible to see big animals, but we are still far from being able 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 giraffe).

One very useful feature to detect animals is the use of thermal infrared. However, this is currently not possible with commercial satellites due to the coarser spatial resolution in this wavelength.

To conclude, even if there are some studies in open savanna or arctic 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).

enter image description here

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  • $\begingroup$ Thanks for expanding on this. Is this related to your work? $\endgroup$ – called2voyage Dec 23 '16 at 21:34
  • $\begingroup$ yes, but indirectly. I don't count animals but sometimes it is usefull to detect them to bring more context for land use classification. $\endgroup$ – radouxju Dec 24 '16 at 11:31
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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:

GeoEye-1 Satellite Image of wildebeest population

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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    $\begingroup$ A few high-res satellite images can be seen here: satimagingcorp.com/gallery $\endgroup$ – called2voyage Dec 22 '16 at 16:23
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    $\begingroup$ Look at this link : theatlantic.com/technology/archive/2015/03/…. Are some high resolution images. $\endgroup$ – Mark777 Dec 22 '16 at 16:25
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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – called2voyage Dec 22 '16 at 22:37
  • $\begingroup$ The whale work built on previous studies looking at emperor penguins; here the majority of the work was focused on the area covered by colonies, but they could (under certain circumstances) identify individuals when standing away from the main group. So that gives a lower bound to the size of an animal you could identify in good conditions. journals.plos.org/plosone/article?id=10.1371/… $\endgroup$ – Andrew Dec 23 '16 at 18:19
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- First count of individual birds from space

- First complete count of an entire species population

The 4-may-2017 BBC News item Albatrosses counted from space describes an effort to automate the analysis of WorldView-3 (Wikipedia and EOPortal) photos in order to count nesting Albatrosses. It is also described in this week's BBC Podcast of Science in Action (available for the next 29 days).

This is the first case of a bird species being counted individually from space.

All six species of Great Albatross are endangered, these are the largest birds capable of sustained flight.

This is the first case of an entire population of a species has been counted. During mating season the entire population roosts on a few tiny islands.

enter image description here

enter image description here

The project is described in the most recent issue of IBIS:

Fretwell, P. T., Scofield, P. and Phillips, R. A. (2017), Using super-high resolution satellite imagery to census threatened albatrosses. Ibis. doi:10.1111/ibi.12482

The study was based on WorldView-3 VHR satellite images, with the visible bands (2/3/5) pan-sharpened to provide a 31-cm resolution colour image using the Gram Schmidt algorithm in ENVI image processing software.

Of the seven visible light channels, 2, 3, and 5 appear to refer to Blue, Green and Red.

enter image description here

enter image description here


Illustration of WorldView-3 Earth observing telescope, from here

enter image description here


From Satellite Imaging Corporation:

enter image description here

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Whales seen from space, and not by the USS Enterprise.

The BBC item Scientists count whales from space includes an audio interview with Hannah Cubaynes and says:

The researchers, from the British Antarctic Survey (BAS), have been using the highest resolution satellite pictures available.

Even when taken from 620km up, this imagery is sharp enough to capture the distinctive shapes of different species.

The team will soon conduct an audit of fin whales in the Mediterranean.

The first-of-its-kind assessment will be partly automated by employing a computer program to search through the satellite data.

[...] This new approach from BAS has drawn on imagery from the WorldView-3 spacecraft operated by the American company DigitalGloble.

WorldView-3 is able to discern things at the Earth's surface as small as 31cm across. Only restricted military systems see finer detail.

"Satellites have improved so much with their spatial resolution," explained Hannah Cubaynes, who is affiliated to both Cambridge University and BAS.

"For the first time we've been able to see features that are truly distinctive of whales, such as their flippers and flukes."

[...] Spacecraft will gather huge image swaths when they pass over the ocean. With the exceptional resolution now available, counting individual whales becomes practical. In a 31cm-resolution image, for instance, a grey whale's fluke will take up 10 pixels.

[...] Ms Cubaynes and colleagues have published their research in the journal Marine Mammal Science.

BBC Whales from Space

above: "At a resolution of 31cm, species identification becomes much easier" Source

BBC Whales from Space

above: "Fin whale: Colour contrast helps with their identification" Source


Whales from space: Four mysticete species described using new VHR satellite imagery Cubaynes, H. C, et al, 2018 Marine Mammal Science

Cubaynes, H. C, et al, 2018 Marine Mammal Science

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In the NPR news article Have You Herd? Farmer Writes A Memoo Using Cows And Satellite Imagery the following YouTube video is linked. Lower your volume slightly before playing:

Although I am not sure yet, (and so have asked this question) I think that the image below is that of some cows saying "Hi!" taken by a 4-inch telescope in a 3U cubesat, or Dove.

enter image description here

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