A spatial operation in which two or more maps or layers registered to a common coordinate system are superimposed, either digitally or on a transparent material, for the purpose of showing the relationships between features that occupy the same geographic space.
12
votes
3answers
5k views
Layers having the same coordinate system should overlap, but they don't. What's wrong?
I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
4
votes
4answers
3k views
How to reproject base layers in OpenLayers?
The issue is:
I have vector/topo/image tiled maps for some places in north america which were published as ArcGIS Server REST service. These maps (A) are based in EPSG26912 projection. Now I wanna ...
6
votes
1answer
2k views
Openlayers wfs vector layer
I'm trying to add a vector layer with a wfs layer and it's not working.Can anyone point a solution?
Openlayers code:
var wfs = new OpenLayers.Layer.Vector(
"Stavros Features",
...
5
votes
4answers
977 views
explode overlapping polygons to new non-overlapping features
Given multiple polygons that overlap in multiple ways, I would like to export from this feature all polygons that don't overlap with others iteratively. The product would be a number of features with ...
6
votes
1answer
273 views
overlay county shapefiles for 2 different years
I have county-level shapefile for South Caroline in 1880 and one for 1940. I would like to overlay these two files so that they do the union and indicate the percentage of the land in 1880 that went ...
4
votes
1answer
785 views
Does OpenLayers supports KML Ground Overlays?
I am not able to display Ground Overlays in a KML file with OpenLayers. Does OpenLayers supports KML Ground Overlays? If not, how would I proceed in writing my own code or plugin for OpenLayers so ...
3
votes
2answers
768 views
Load layers only when zoom level is reached
I'm trying to load different layers based on the user zoom level with OpenLayers. I've seen some similar questions in here, but they load the layer and then hide/show it based on the zoom level.
I ...
5
votes
1answer
588 views
How to rasterize SpatialPolygons in R?
I'm trying to extract the bathymetry values of my area of interest from a world bathymetry raster layer using the 'rasterize' function in the {sp} package.
*Edits: I found the 'extract' function ...
5
votes
7answers
971 views
Problem with Swiss coordinate system overlay in WMS
I have administrative boundaries data for communities in Switzerland from SwissTopo. Original data came in shape files with 'Bessel 1841 Hotine Oblique Mercator Azimuth Natural Origin' projection.
...
3
votes
2answers
426 views
Clip depth contour with spatial polygon
I need to somehow combine my Spatialpolygons with my depth contour, but not sure how do to so. Maybe create a SpatialPolygonsDataframe?
This is what I've done so far:
> class(subarea0) #This is ...
1
vote
1answer
244 views
Can't display overlay
I am trying to add a WMS radar overlay to my map but it won't seem to gather it.
noaaRdr = new OpenLayers.Layer.WMS("Latest Radar", "http://nowcoast.noaa.gov/wms/com.esri.wms.Esrimap/obs?", {
...
1
vote
2answers
294 views
QGIS layers no longer overlay when Enable 'on the fly' CRS transformation is on
My QGIS project has two layers - one retrieved from GADM (administrative boundaries of Guinea Bissau) and another one of the villages collected in the field using GPS Decimal Degrees - D.ddddd.
If I ...
