Linked Questions

105
votes
5answers
177k views

Algorithm for offsetting a latitude/longitude by some amount of meters

I'm looking for an algorithm which when given a latitude and longitude pair and a vector translation in meters in Cartesian coordinates (x,y) would give me a new coordinate. Sort of like a reverse ...
5
votes
1answer
401 views

Slope layer with false results in QGIS? [duplicate]

After the DEM creation, I wanted to create slope layer. However, the result has not satisfied me. I don't think the slope map is correct. Have you ever encountered false calculated terrain map? ...
4
votes
1answer
872 views

Producing Hillshade in QGIS?

I have been trying to create a hillshade using DEM data, however, regardless of the scale and z values I use the output is all black. I accessed the DEM data from a government source and clipped it ...
3
votes
2answers
4k views

Getting incorrect slope values from an ASTER DEM in QGIS?

I have a DEM layer from ASTER satellite and I want to get the slope information from it. I use terrain analysis > slope, but the output is so wrong. Why is that? Here is the DEM: And here is the "...
3
votes
1answer
76 views

Unexpected results with Raster Terrain Analysis Plugin

In QGIS 2.18.18 on Windows 10, I have downloaded the NASA file srtm_05_01.tif that is available at http://dwtkns.com/srtm. I use the Terrain Analysis Slope method on that file with the following ...
2
votes
3answers
4k views

Using .tif files to get elevation and slope in ArcMap? [closed]

I'm using ArcMap 10.3 on Windows 10 and I have the 3D analyst, ArcScan, Geo-statistical analyst, network analyst, publisher, schematics, spatial analyst and tracking analyst extensions. I have a ...
1
vote
1answer
40 views

Creating slope map with ArcGIS Desktop?

I created slope map with DEM model in ArcGIS Desktop. But it is only categorize in to two sections. I think it is problem with the horizontal and vertical scale. I used WGS84 coordinate system. How ...
1
vote
1answer
127 views

'Scale' value in slope percent map in QGIS? [duplicate]

What value should be used for scale while calculating slope percent in QGIS? Some documents suggest is as 111120 and some as 365130. I am using ESPG 4326 projection and do I need to convert this ...
1
vote
1answer
379 views

What's the right way to calculate the scale parameter value for r.relief in GRASS?

I have a little doubt about the way I should calculate the value of the "scale" parameter in the r.relief command in GRASS. In the description section of the r.relief page of the GRASS manual I read: ...
1
vote
0answers
183 views

Scale factor for DEM Slope in QGIS? [duplicate]

My DEM raster coordinates are in WGS84: 45.4763884,-121.5736061 and vertical units are in feet I believe. I want to do a slope analysis. Do I need to add scale factor? I have been seeing different ...
0
votes
2answers
39 views

Hillshade not displaying correctly in ArcGIS Pro?

I have a large DEM of England that I have clipped to my study area and have been trying to generate a hillshade from. I tried a few variations with the parameters in altitude and azimuth (leaving z =1)...