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 ...
10
votes
1answer
353 views
Method to shade or overlay a raster map to reflect time of day and ambient light
I have a daytime raster of my study area.
I have 20+ counters in the study area that count "stuff" with a timestamp.
Using PyEphem I determined the type of ambient light for each collected data ...
8
votes
1answer
1k views
How do I create an animation in google earth using png overlays with kml timestamps?
I have the following kml files, each with a different timestamp and png:
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2"
...
7
votes
2answers
5k views
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 ...
6
votes
1answer
2k views
Draw route direction overlay on Google Maps or OpenLayers
I'd like to display the route direction generated from GraphServer on either Google Map or OpenLayers. The result I want is basically identical to how Google Map shows route directions, by ...
5
votes
7answers
970 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.
...
5
votes
1answer
111 views
What tool do I need to have satellite background images to draw features of a postgis database?
What tool do I need to have satellite background images to draw features of a postgis database?
I looked about Geomajas but seems very complex for what I'm trying to do.
I have osm data imported in ...
5
votes
4answers
968 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 ...
5
votes
1answer
2k views
Can image layer be rotated in OpenLayers?
While working on Ground Overlays, I noticed that it has a tag called <rotation>
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
...
5
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
1answer
579 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
2answers
487 views
BBOX and Projections of WMS services in Geoserver
we have tried to overlay a raster layer on Google map and have some difficulties to align the raster images onto the base map. When it is on the overview (Zoom level 1), it looks like this:
On a ...
5
votes
2answers
2k views
How to display image overlays in OpenLayers?
I am working on displaying Ground Overlays on OpenLayers by parsing KML manually.
To do so, I was trying to add an image on top of Google Map by looking at GroundOverlay section from ...
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 ...
4
votes
3answers
242 views
Can I have Points, Lines and Polygon features in one QGIS layer?
I have a situation where planning is done on a "base map" consisting of rivers, contours, roads etc. There is a need to create a "overlay(s)" over the "base map" consisting of drawings, that could be ...
4
votes
2answers
191 views
Finding Raster Overlap within a Directory
Here is the scenario:
I have a directory with 100+ map projected, single band, rasters that weighs in a 40GB+. I have used ArcMap's built-in mosaicing tools to create a raster mosaic. I am using a ...
4
votes
1answer
781 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 ...
4
votes
2answers
342 views
Display Georeferenced Images on Android
I'm looking for an Android application (best would be Open Source), that can display georeferenced images on top of a map (Google, OSM, ...).
By Georeferenced I mean that the images four corners are ...
4
votes
1answer
193 views
Generate tiles for google maps overlays
I am trying to show some information on Google Maps which would be in the form of translucent circle overlays. The problem is that some circles overlap, which results in increased opacity and blending ...
3
votes
2answers
65 views
How to calculate the shared area between a raster and a shape file in ArcGIS 10?
I have a raster file with 5 classifications developed from habitat modelling algorithms. I'd like to know how much of 2 classes of the raster is covered by the network of protected areas (Shape file). ...
3
votes
3answers
140 views
Is the Intersection Operation Commutative?
In map overlay, is intersection of map layers a commutative operation ie layer_A intersection layer_B = layer_B intersection layer_A?
If layer A is a square and layer B is a triangle. In this case, (A ...
3
votes
1answer
1k views
OpenLayers doesn't show an overlay with a different SRS than the base layer
I need to add an overlay layer that uses EPSG:4326 to a map with a base layer that uses EPSG:32628.
Every time I add the overlay OpenLayers automatically switches the SRS param of the overlay to ...
3
votes
2answers
423 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 ...
3
votes
2answers
98 views
Overlay Vector Layer on Raster Layer
How can I overlay a Vector Layer on a Raster Layer and assign NoData Values on the Raster where the Vector Layer does not cover the Raster Layer?
(preferable with ArcGIS)
3
votes
2answers
146 views
calculate coastline at risk
I have an idea of what I want to do but I don't know yet what tools will bring me there.
I have administrative boundaries in one layer and coastline in another layer. The coastline is categorized in ...
3
votes
1answer
260 views
Shapefile vs Arrays of coordinates to build Google Maps overlay?
I am very new to GIS, and my task is to overlay about 100 polygons on a map. I'm using Google Maps Javascript API v3.
I think I can define all my polygons as sets of lat/long coordinates in my ...
3
votes
3answers
3k views
OpenLayers: Showing a WFS overlay on top of Google Maps
I have found similar questions asked previously, but I still fail to get a simple WFS point layer to work using OpenLayers and Google Maps. The original code I used was based on WFS polygon layers I ...
3
votes
1answer
96 views
Find which grid cells contain a point
I have a dataframe with x,y coordinates. I've sampled 10 x,y coordinates from my dataframe:
y <-c(24.637032,21.569813,21.687,19.677183,24.72438,21.433136,24.637032,22.21065,21.443762,25.273882)
x ...
3
votes
1answer
617 views
Why does my WMS layer overlap the Google Maps v3 logo?
I'm using Google Maps v3 as a base layer and on top of that I create an overlay pointing to my WMS (streets and avenues).
A few months ago all works fine, my WMS layer was not overlapping the Google ...
3
votes
1answer
160 views
Calculating the time taken to complete the overlay display in map?
Currently, I am able to calculate the server response time by logging the difference of current date to initialize the map with the time when layers is added. But this gives me server response time. ...
3
votes
3answers
562 views
Overlay polygons on raster colour map to extract area values for each colour within each polygon
Does anyone know an answer to the following:
I have a set of polygons created as the MCP of animal movements. I also have a habitat colour map raster, with 13 different habitat types as different ...
3
votes
1answer
416 views
UK region overlay on map
I'm hoping to overlay UK regions (East Midlands, Wales, London etc) on a Google Map. Ideally the regions could be coloured, opaque and have some form of label. There is no hover / interaction ...
3
votes
2answers
758 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 ...
2
votes
2answers
1k views
How to overlay map layers (shp and csv) in R?
This is a crosspost from stackoverflow. I know very little about GIS software and am doing all my mapping in R. Apologies in advance if this is too basic question. Let's say I have two shapefiles from ...
2
votes
3answers
739 views
How do i identify features within a buffer?
I have a point shapefile that identifies the location of incinerators in England and an output area classification shapefile. I have created a buffer for all the points in the shapefile because i want ...
2
votes
3answers
2k views
Can OpenStreetMap be used as a WMS service in MapServer?
I want to produce a png image that uses OpenStreetMap data and has a vector overlaid on the base data. I am able to produce the vector overlay from within Mapserver, but I have difficulty ...
2
votes
2answers
694 views
Image display/scaling in OpenLayers vs Google Maps
When I plot an image on OpenLayers, it looks like that image is stretched a little bit as compared to Google Maps. I was wondering if it is normal or there is something wrong with my code.
...
2
votes
1answer
308 views
polygon map overlay algorithm
There are many algorithms for binary map overlay operation in vector data format which take two layers of map and produce resultant layer i.e overlaid layer as output.
I am wondering whether there are ...
2
votes
1answer
70 views
How can I enable panning using Openlayers and a vector overlay with controls?
I am creating a map using the following code:
map = new OpenLayers.Map({
div: "map"
});
Then I load in a geojson polygon layer and add two controls
var highlightCtrl = new ...
2
votes
1answer
352 views
Select vectors overlapping a raster
I have a raster layer with travel times from a specified point in my city's downtown. What I'd like to do is select all of the census blocks that lie at least partially within 45 minutes of downtown ...
2
votes
1answer
124 views
Overlay analysis of topographic data
I have a topographic map with Buildings, Roads, Hydro and land use as the prominent layers in polygon format. Also i have newly collected Building polygons of the same area in shape file format. Now i ...
2
votes
1answer
173 views
Technique using GDAL to overlay / fit one PNG map to directly overlay on another?
I have one .PNG basemap with known North edge of Latitude = 52.48, a South edge of Latitude = 21.94, an east edge of Longitude = -61.87 and a west edge of Longitude = -129.37.
And I have another PNG ...
2
votes
0answers
203 views
Area overlay of census on Zip Code
I have census block data polygons. I want to overlay them over Zip Codes (larger polygons) in order to estimate the population in the Zip Codes. Or overlay buffers around toxic waste sites over census ...
2
votes
0answers
243 views
Creating a sidewalk map for a walkability survey
If I wanted to do my own walkability survey of my city, what tools could I use? I have map data from OpenStreetMap, but I have to consider that streets have two sides (which aren't always accessible ...
1
vote
1answer
239 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
240 views
count features in polygon shapefile A that fall within each feature of polygon shapefile B
I have two polygon shapefiles, each of which contain multiple (possibly overlapping) polygons.
Is there some way, using GRASS, to calculate the number of polygons belonging to shapefile A that fall ...
1
vote
2answers
680 views
OpenLayers WMS disappears when including OpenStreetMap
Setup:
ArcSDE 9.3.2
Oracle 11g
GeoServer 2.1.4
OpenLayers (latest build)
OpenStreetMap
InternetExplorer 7.0/ Google Chrome
EDIT: I have updated information just below the screen shots
...
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 ...
1
vote
1answer
149 views
How to display Lidar Data in ee0 (Interchange File) on Maps
Hi I have Lidar data in ee0 files (interchange files). Can i ovaerlay them on some maps like say Bing Maps or Geoserver with Open Layers?
If yes whats the right way of doing it?
Thanks
