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.

learn more… | top users | synonyms

5
votes
3answers
2k 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 ...
6
votes
2answers
519 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 ...
0
votes
1answer
31 views

Overlay single, non georeferenced image in Leaflet?

I'm wondering whether it would be possible to somehow overlay a 3rd party, changing non-georeferenced image such as: If the image was static, I'd use mapwarper.net. But it's not. So is there a way ...
1
vote
1answer
26 views

How to convert Geodatabase to open standards to process it further?

I have a ESRI file in geodatabase format (v9.3). I intend to use this in a non-commercial application. I think I will have to convert it into a open standard since I am confused if ArcGIS online would ...
0
votes
1answer
245 views

I can not override my WMS layer in Google Maps as a base

I can not override my WMS layer in Google Maps as a base: I have a WMS layer in geoserver am using openlayers to show them. Calling only works WMS layer:   see my code, I am using using the bounds ...
0
votes
1answer
31 views

How do I view ovl files on Geogrid or Top50 then convert the data to shapefiles?

I have some .ovl files which can only opened on Geogrid or Top50 viewer which shows me where everything is. How do I take these ovl files and convert the properties to Shapefiles to be used on ArcMap ...
1
vote
0answers
22 views

Raster overview hierarchy in WMS [duplicate]

I have rasters with low resolution which covers the whole area, and in certain spots i have some rasters with higher resolution which covers small parts of the same are covered by the lower raster ...
0
votes
0answers
30 views

Why does a (relatively) small .CSV file break the Mapnik CSV plugin?

I have an app showing a map of N. America, and I want to let users toggle a layer displaying airports. The map needs to be available without an Internet connection, so I'm hosting the tiles and ...
2
votes
2answers
5k views

How do I overlay a KML on leaflet 0.4.4

I am using Leaflet 0.4.4, I have a KML I would like to overlay on the map, how do I go about doing this? Edit: I am already aware of https://github.com/CloudMade/Leaflet/issues/14, which directs ...
3
votes
3answers
193 views

Display millions of points in the browser

I have a web application which will track he movement of user, and save the history location to database. And user may want to see his/her movement trace over a period of time, we have to display ...
1
vote
1answer
58 views

Trying to overlay Ordnance Survey Tiles onto a different OpenLayers TileLayer

I am trying to add two layers to a Map using OpenLayers 3, one is the information from Bing Maps, and the other is data from the Ordnance Survey data. I have both maps displaying correctly in ...
1
vote
1answer
202 views

How to open overlay content from leaflet popup

Hi! I am currently working on an interactive leaflet map. I managed to display markers from a database via php (create an array). Now I want users to create markers with a click on the map. To add a ...
2
votes
0answers
34 views

Check/uncheck overlays in groupedlayercontrol.js

In a Leaflet-based app I have create several overlays, grouped with leaflet.groupedlayercontrol.js, as shown in this image: Everything works well, but I need to uncheck certain layers, allowing the ...
1
vote
1answer
39 views

2 Legends in Leaflet

In Leaflet I want to add a legend when I turn on an overlay, then when I turn off that overlay I want the legend to disappear and when I turn on a second overlay I want a second legend to appear. I ...
1
vote
2answers
478 views

OpenLayers: Strange Tiling Issue (Checkered, white and grey) when panning around map

So this strange tiling issue is only occuring when moving around the map. Some things to note: 1) You can see the markers, airplane icon, and flight paths. These are all overlays, where the actual ...
1
vote
1answer
83 views

Testing point in polygon overlay performance of Intersect, Spatial Join and Near in ArcGIS for Desktop?

In answers and comments to Select points within a polygon and update attributes I think it is being suggested that Spatial Join (Analysis) and/or Near (Analysis) may be faster than Intersect ...
2
votes
1answer
82 views

How to get a GML overlay on Google Maps?

Anyone know how to get a GML file to show as an overlay on Google Maps? To be honest I don't know my GML from my KML, or my ETRS89 from my WGS84, as this topic is completely new to me. A bit of ...
2
votes
0answers
39 views

How I can create a raster and have the same overlay as another raster in QGIS 2.4?

I have made a graphical model in QGIS 2.4. I have to create a raster equation to rasterize a polygon shapefile. I want to rasterize my shapefile and I want to ensure that this new raster will ...
1
vote
0answers
208 views

How to overlay a flat image onto google maps with two points of reference?

The Android API allows for images to be superimposed onto a map. To do so, the developer specifies a set of lat/long coordinates for an "anchor point" within the image, the width (or height) of the ...
1
vote
1answer
87 views

Reprojected Shapefile does not align with Openlayers Plugin

I am based in NSW, Australia. I have a shapefile that when I underlay with the openlayer plugin (google satellite), the shapefile is skewed despite all my efforts to correct it. I changed the ...
2
votes
1answer
39 views

Question regarding area overlap

I'm using land use data, and report the proportion of each sub-catchment that is used for “Grazing Modified Pastures” and “Irrigated Modified Pastures”. I'm essentially focused on these two layers, ...
2
votes
2answers
53 views

How to add updated tiles to ArcGIS mosaic

I have several hundred aerial imagery raster tiles (in ecw format) that I have loaded into a mosaic dataset. I would now like to 'replace' or 'overlay' an older aerial imagery layer with this dataset. ...
2
votes
1answer
78 views

Import data, analyze spatially, and export list of points using Google Earth

I am trying to: import data into Google Earth from an outside data source. Then overlay a map and isolate which datapoints fall into that area. I would like to then export a list of the data points ...
3
votes
1answer
90 views

How to overlay a county boundary on a raster file?

I want to overlay California county boundary top of raster layer. Here is is my code: data(coastsCoarse) data(countriesLow) library(gtools) library(maps) library(maptools) library(sp) # Raster ...
1
vote
2answers
375 views

Transforming a Google Maps overlay to fit an Ordnance Survey projection

I am currently in the process of creating a map with some administrative boundaries on it. The base map I am using is an ordnance survey map 1:10000. I downloaded an administrative border as a .kml ...
3
votes
1answer
472 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 ...
0
votes
0answers
62 views

How to hide overlays in Leaflet layerControl if geojson var not found?

i would like to perform a specific task: i have a set of geojson layers, loading features from local files. i have the layercontrol on the map showing available layers to show/hide now, regarding ...
2
votes
1answer
42 views

strange banding in output raster after weighted overlay

I am trying to conduct a weighted overlay. I have two rasters, one is a continuous slope raster that I reclassified to have 6 classes (8bit signed integer), and one is an elevation raster that I also ...
0
votes
1answer
100 views

Image source of world political map for Google Maps overlay in Android?

I have searched a lot. But I am not able to find some high resolution image of world map showing countries in different colors without label, which I can slice and use to create tile overlay in my ...
1
vote
1answer
67 views

Erasing overlay geometry with in the feature class..!

What is the best practice for erasing overlay geometry? My scenario is: I have a polygon layer with 1000 features. i need to create a tool from model builder that select polygons with user defined ...
0
votes
2answers
58 views

OpenLayers + Geoserver problem with wfs projection

In geoserver i have a layer in EPSG:26191. In OpenLayers i add it on map as WFS: markerLayer = new OpenLayers.Layer.Vector('Markers',{ strategies: [new OpenLayers.Strategy.Fixed()], ...
1
vote
0answers
18 views

How to overlay an NOAA nautical map as a layer in QGIS [duplicate]

I am new to QGIS and am doing some work for a friend. He is hoping to overlay an NOAA nautical map as a layer in QGIS. My only real experience is with ArcGIS. He is looking to do something similar ...
0
votes
0answers
53 views

Overlaying Line (Vector) Layer on Raster Zones?

I will make my best attempt to clearly explain my problem. I am using ArcGIS 10 I have a raster layer with 3 values that make up zones. For the purpose of this example, lets say these zones are ...
1
vote
1answer
148 views

Apportion Neighborhood Information to Census Tracts

I have a shapefile of census tracts and another shapefile of "neighborhoods" with values that I need to have joined to the census tracts. I know I need to apportion the area of the neighborhood ...
0
votes
0answers
46 views

Is the geoxml3 javascript API compatible with the mapstraction API?

I am getting ready to revamp a google maps application and I was considering utilizing mapstraction. I am currently using all google maps js, with a kml layer overlay, but obviously by using the ...
0
votes
1answer
59 views

Kml not overlaying onto Google Map

I created a basic dashboard with MVC 4, visual studio 2012, The dashboard displays a Google map. Here is an image of the dashboard: My intention is to be able to take this Kml file: And ...
0
votes
1answer
58 views

Selecting raster data by location: for raster and feature class data

I have rasters covering certain spots in my environment, I'm looking for a way to extract the values which occur at locations which are defined by a selection of feature layers. I've tried with the ...
0
votes
1answer
87 views

How to overlay a jpg onto a google earth image?

I have produced a model from an online engine , and it is in a google earth picture. I want to georeference the below picture and apply the boundaries here on my google earth image. I'm using QGIS2.2. ...
0
votes
2answers
57 views

Frequency analysis and overlay analysis

Am new to gis and I hope to find help here. I am working on a research that requires that I overlay conditions of drainage systems and quality of healthcare in a coastal state to get areas which have ...
1
vote
1answer
471 views

Merge two maps with OR operation in GRASS

I have two vector maps. The two maps cover the same area but are split up into polygons differently (i.e. if you were to imagine one map placed above the other, the lines defining the polygons would ...
0
votes
0answers
21 views

Spatio-temporal Overlay

I have a SpatialPointsDataFrame that lists satellite-detected fires (firesutm), including location and date. I also have a SpatialPolygonsDataFrame with county boundaries (countyutm). I would like ...
0
votes
0answers
129 views

QGis, how to overlay and correctly position and scale a KML and image onto a Google base map

Being totally new to the entire GIS subject I managed to install and get runnning QGis (2.2.0 on Mac) properly, get my Google Maps showing (I set the the CRS to WPSG:3857) and I also got my KML file ...
4
votes
1answer
177 views

Show markers only at certain zoom levels

I'm building a cycle touring map in leaflet.js, with subjective information overlaid as markers, along the lines of "this is a great road", "this town is quite nice" etc. To avoid information ...
1
vote
1answer
45 views

Combining several rasters before r.surf.contour?

I have been trying to generate an elevation model from contour lines using first v.to.rast.attr and then r.surf.contour. Generally, it works pretty well, execpt for one issue. My data contains a lot ...
1
vote
1answer
77 views

Overlap or intersect two choropleth [closed]

I have two choropleth of the same area but with different concentration data and I need to overlap them. My aim is to highlight the areas of intersection between the points with the highest ...
0
votes
1answer
94 views

Weighted Overlay with “nodata” cells

I´m currently conducting a suitability analysis with the weighted overlay function. One relevant criteria is the proximity to highways. If the wind turbine is located up to 300 m away from the ...
1
vote
0answers
111 views

Problem with polygon overlay in raster stats using gdal

I am using the raster_stats module in python to calculate the mean carbon value for different sets of polygons. Here is the code that I am using: africa_sat = ...
1
vote
1answer
71 views

Stamp out and transfer values from one overlayed vector layer to another

I have a vector layer with administrative boundaries and another vector layer with postal code boundaries, which are more precise/smaller entities/objects. I now want to transmit the values of one ...
0
votes
0answers
18 views

Openlayers and Geoserver: Google Maps and WMS Overlay [duplicate]

I'm trying to overlay a WMS layer in Google Maps. My coat is already projected in EPSG: 3857 and has prj file. I used the following command in postgis to confirm: the result EPSG:3857 SELECT ...