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.

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2
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0answers
19 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 ...
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1answer
49 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 ...
1
vote
1answer
24 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
1answer
45 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
55 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
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0answers
33 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 ...
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0answers
96 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
66 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
36 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
44 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. ...
3
votes
1answer
72 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 ...
2
votes
1answer
65 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 ...
0
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0answers
53 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 ...
0
votes
1answer
87 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
60 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 ...
1
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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
2answers
47 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()], ...
2
votes
1answer
36 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
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0answers
39 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
77 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
34 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
45 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
50 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
68 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
45 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 ...
0
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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
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0answers
97 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
125 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
39 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
65 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
76 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
96 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 = ...
0
votes
0answers
17 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 ...
0
votes
1answer
224 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 ...
1
vote
0answers
42 views

Calculating Percent Overlap Between Distribution Maps

Hello there, I am currently trying to calculate the percent overlap (basically the total amount of overlap where these two species come into contact) between Lithobates catesbeiana (first image) ...
1
vote
1answer
50 views

Extract information of a raster overlayed on another raster with a lower resolution directly in python

I have two aligned rasters with the same extent, one has a resolution of 5 meters and the other of 125 meters. I would like to place the 5 meter one over the 125 meter one and assign to these smaller ...
1
vote
1answer
84 views

How to combine Boolean and Fuzzy logic?

So I have a set of 5 Fuzzy Memberships and a polygon feature class, to which I already added a yes/no field. For the final map, I need to combine/overlay all Fuzzy Memberships and the rasterized ...
0
votes
1answer
26 views

How to select the identities of a layer present just in one identity of another layer

I'm a student approaching to QGIS 2.0.1-Dufour. My goal is to know how much identities of a layer are present just in one identity of another layer. I tried both with the tools "spatial query" and ...
1
vote
1answer
75 views

QGIS 2.0: move basemap by hand in order to achieve overlaying with a point layer

I am an environmental engineer and the aim of my QGIS 2.0 project is to visualize the results of a sewage water system inspection. In a first step I included the hoppers from a csv file and added a ...
1
vote
2answers
67 views

Historical maps as cylindrical projections

Objective: I want to overlay old, historical maps on top of Google Maps. According to Wikipedia, Google Maps uses a variant of the Mercator projection, a close relative of cylindrical projections. ...
1
vote
0answers
113 views

QGIS plug-in equivalent of ArcGIS's Spatial Analyst Tools -> Overlay/ Weighted Overlay

Specifically I have 12 .bil raster files that show monthly global mean minimum temperature. I file for each month. I want to combine these to create an ANNUAL global mean minimum temperature. In Arc I ...
1
vote
0answers
143 views

Replace google map MARKER with HTML element

I want to add a custom HTML element (that can become transparent dynamically) instead of a marker. Basically my html object would be a cirle (or rounded pin) with a picture of users in the middle. ...
0
votes
0answers
29 views

Overlapping of two layers in MySQL spacial extensions

I have been into GIS for almost a week now. Right now, I am learning MySQL spacial extensions. I have a question regarding the functions MySQL provides: I have a table that consists of LineString, ...
0
votes
0answers
54 views

Removing multiple categories from GRASS vector feature

Pardon my lingo if this is not entirely correct - I am a software developer, not a GIS person. We're working a project that uses v.overlay to merge a map of slopes with a map of soil tests to produce ...
0
votes
0answers
155 views

How to import AutoCAD .dwg files as overlay on map in Drupal (using OpenLayers)

I am using OpenLayers on my Drupal site. The request is to import AutoCAD .dwg files as an overlay to maps on the site. Is this possible and how? I found the OpenLayers Editor for Drupal, am I on the ...
0
votes
0answers
46 views

Not a valid data source of kml created from image overlay by Google Earth

I did image overlay in Google Earth and saved it as kml file. But it was showing me that it is not a valid data source when add it as vector(kml) in Qgis 1.8.0. Any solutions? Thanks!
0
votes
1answer
47 views

Calculate best area with overlaying multiple layers buffer shapes

I am using QGis and I have a set of 20 layers with buffers. I'm interested in where they overlap most and I want to create a single layer that shows which are the places where they overlap most and ...
0
votes
0answers
21 views

No values in overlay tab, only in diagram tab

I have basically the same issue like in this post. I joined a table to a .shp with the intention to display those values (integers) as a column overlay. Producing pie charts (Diagram tab) works fine, ...
3
votes
1answer
297 views

remove land area from marine region polygons

In my pursuit to merge multiple polygons for the purpose of calculating the surface area of marine species distributions, using shapefiles from Marineregions, I am now trying to remove potential land ...
2
votes
3answers
270 views

Produce a list of polygons that a line crosses

I have a polyline feature class and a polygon feature class. What I want to do is add a field to the lines that lists all polygons that touch the line. This is effectively performing a ...