What is the difference between Bing Maps, Here WeGo and Google Earth imagery in this area?

Question

We are working on a project about the exploration of historical ruins via publicly available satellite imagery. This project is for a high school scientific research competition.

In the photos below you can see that Bing Maps imagery is different from Here WeGo and Google Earth. Burried ruins of a settlement can be clearly seen in Bing Maps image.

In all of these map services the source of the satellite imagery is shown as DigitalGlobe. We want to know what the difference is between the images apart from "season", if there is any.

coordinates for the example site seen in the photos: 39,050433, 44,015129

Answer 1

DigitalGlobe is the name of a private company that navigates several Earth observation satellites (listed here). It is difficult to find out the actual satellite that took the picture, but the spatial resolution should provide a good hint.

Besides the obvious difference in dates of acquisition (change), there could also be a difference between the sensor used for each image. Each satellite is sensitive to different bandwidth of the light spectrum (the so called spectral response), so this could explain that some colours are not exactly the same. On top of that, the differences of colours are likely to be due to a different constrast stretch of the images, which usually create a larger difference of rendering than the "bandwidth" difference. Finally, you could note that the position of the sun was different (longer shadows on the bing map image, so you are probably in Winter with a "low" sun)

Answer 2

In this case the most likely difference is related to year/date of the capture and the ground sample data (GSD) e.g. 6in vs 9in etc...

Also, other factor can be involved, sun angle on the day of capture, type of camera and specifications. Processing etc...