Timeline for Resolution of NED (National Elevation Dataset)
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 17, 2015 at 21:45 | vote | accept | Iced_ | ||
| Nov 6, 2014 at 7:09 | answer | added | AndreJ | timeline score: 1 | |
| Nov 6, 2014 at 5:48 | comment | added | user30184 | Your own thinking was OK. Degree is degree but near the poles the area of an area with a size of degree by degree is smaller than at the equator when measured in square kilometers on the ground. Whichever way you measured the pixel areas you did not made it with a good method. | |
| Nov 6, 2014 at 5:32 | history | edited | PolyGeo♦ |
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| Nov 6, 2014 at 4:13 | comment | added | If you do not know- just GIS | a degree is a degree is a degree regardless of your location | |
| Nov 6, 2014 at 3:46 | comment | added | Iced_ | It's a nice site! | |
| Nov 6, 2014 at 3:25 | comment | added | Michael Stimson | This link might help show how areas distort gmaps-samples.googlecode.com/svn/trunk/poly/puzzledrag.html and it's kind of fun. | |
| Nov 6, 2014 at 3:08 | comment | added | Michael Stimson | A degree is a degree at the poles or at the equator, it's 1/360 of the circle, likewise a 1/3 by 1/3 degree cell is the same geographic size but the projected size differs greatly. There are cool interactive sites that show the distortions but I can't find one right now. | |
| Nov 6, 2014 at 3:03 | comment | added | Iced_ | Yes, I am using a projected coordinate system. But I still do not understand how the area of a degree longitude has the same area in the north than in the south ... The "longitude lines" are much closer to one another in the north | |
| Nov 6, 2014 at 3:00 | comment | added | Michael Stimson | You must be looking at the DEM in a projected coordinate system. Rasters contain rectangular pixels - mostly rasters have square pixels. The geographic resolution and area covered is the same but when projected is quite different. | |
| Nov 6, 2014 at 2:57 | history | asked | Iced_ | CC BY-SA 3.0 |