Wikipedia:Reference desk/Archives/Computing/2023 November 24
| Computing desk | ||
|---|---|---|
| < November 23 | << Oct | November | Dec >> | Current desk > |
| Welcome to the Wikipedia Computing Reference Desk Archives |
|---|
| The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
November 24[edit]
Google Glitch[edit]
What causes glitches like that on Google Earth/ Map coordinate 1°54'44"N 31°14'03"E ? The more you zoom in, the weirder it becomes. ExclusiveEditor Notify Me! 15:59, 24 November 2023 (UTC)
- It isn't Google Maps. It is Maxar Technologies Imagery. This is a well-known issue when taking satellite images over water. Sun glint messes with the color sensors in the camera, causing strange artifiacts. That is why you see it over the water, but it stops when you hit land. What makes it worse is that the area's imagery is clearly cobbled together from multiple passes of various satellites at rather different times with very different capabilities. You see some areas with detail and other areas with weird colors and no detail. Zoom just right and you can see the borders of each of the original images used to cobble it all together. 97.82.165.112 (talk) 19:16, 24 November 2023 (UTC)
- What doesn't help is the way these satellite sensors are made. A system of mirrors and/or lenses projects the light on a series of linear sensors, placed parallel to each other, one for each colour. The movement of the satellite moves the image over the sensor array. These scan the Earth's surface for half an orbit (it doesn't work on the night side of the Earth). The result is that the images in different colours are taken at slightly different times and directions. Sun glint is highly directional, so that leaves coloured artefacts. Rapidly moving objects like aeroplanes also cause coloured artefacts. The issue doesn't appear on satellites that point a camera and take pictures one by one, but those non-scanning satellites are only used for high-resolution images of places of special interest, or low-resolution images of the entire Earth. Most of the high-resolution images on Google Earth come from aeroplanes, using pretty standard cameras pointing straight down and taking a picture every few seconds. On those, rapidly moving objects often show up as duplicates. PiusImpavidus (talk) 11:12, 25 November 2023 (UTC)