Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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How to get transparent nodata values in GeoExplorer?

I have a single-band raster image with NoData values set to 0. Is it possible to get them transparent in GeoExplorer?
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Error Using Open Layers 3 Web mapping Applications [duplicate]

As being new to website development, i have been able to display map on my website, but I want that i should only zoom to some specific places of india on loading of web pages. Can somebody please ...
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104 views

Raster image does not show up in Data View

I'm a new GIS Student. I created and imported 3 raster files for last week's lab. In our lab this week, we are creating a vector image using the raster data. When I import the 3 raster files, it ...
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137 views

Using gdal ReadAsArray or Arcpy.RasterToNumPyArray on python 2.6 32bit without it crashing

I am trying to run ReadAsArray on an entire raster and on a single band, python will crash without an error message when trying to do either. Is there a way I can create a 3d array without having to ...
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How to merge elevation from a raster image onto a shape road network with QGIS? [duplicate]

I have a shape file with Stockholms road network and a raster image with elevation data from the same area. Is there any way to merge the two somehow, either by adding the slope direction as ...
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276 views

How to set the cell size of a tiff to 1 meter when working in a Geographic Coordinate System?

I am working in a Geographic coordinate system in ArcGIS, and I need to create TIFFs by exporting rasters. THese .TIF file must have a resolution (cell size, or GSD) of 1 m. Is it possible to set any ...
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173 views

using r.volume model GRASS plugin in QGIS

I am calculating volume of bathymetric data in the form of a clipped raster in GRASS with a Custom Lambert projection centered around 70degrees North, using the module r.volume in GRASS. Side note: ...
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155 views

Making grayscale map from multiple band satellite image in ArcGIS for Desktop?

I have satellite multiple band map, I needs to make grayscale map,what should i do? what is the steps? which band and format of input are to be used in this? How to make attribute table of this? In ...
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167 views

Raster created by python GDAL interpreted upside down

I am using CRS which has axis in left bottom corner. Code below produce Geotiff which is shown allright in QGIS but when I open it in other software it is upside down. Also gdal_calc takes it as ...
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82 views

Setting resolution for GRASS raster

I am trying to calculate volume using the GRASSplugin. I have my area information in vector format and my depth information in raster. I read that it is important to set the raster resolution before ...
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99 views

Error on 'Extract raster values to CSV' in batch process in QGIS

The Extract values (csv) contained a bug in the script. The below link shows how to correct the bug. Error on 'Extract raster values (CSV)' - Error executing algorithm 1 'Dataset' ...
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61 views

What kind of methods are most commonly used to interpolate a relief?

I have got a topographic plan with height measurements which I converted to point shape file with height value in attributes. I was wondering, what kind of methods are most commonly used to ...
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17 views

Calculation of RMS between two grids [duplicate]

I want to calculate the RMSE of two grids based on their z-value: a calculated and a reference grid. I do have the statistics: Cells, Range, Min, Max, Sum, Mean, Variance, St.dev. How could I solve ...
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1answer
99 views

Error on 'Extract raster values (CSV)' - Error executing algorithm 1 'Dataset' object has no attribute 'mapToPixel' See log for more details

I would like to extract raster values at some locations (point shapefile) in 'csv' format. I use 'Point Sampling Tool' and it works well for a raster file. However, I have hundred of raster files ...
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88 views

DEM error when trying to do topographic correction in GRASS

I'm new to GRASS gis and I'm trying to do a topographic correction (i.topo.corr) of 9 ASTER bands using SRTM dem. I keep getting this error message: ERROR: Illumination model is of CELL type Is ...
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64 views

ArcGIS Viewshed's show no visibility to south east

I'm using ArcGIS 10.2.2. I've been running some viewsheds using DTM files from EDINA Digimap and data that I've imported using .csv files. These files only contain the X Y details and a code for each ...
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62 views

Urban Heat Island USING ENVI

I have downloaded MODIS images for a specified area.. Its my first time that I am working on UHI (Urban Heat Island).. I need to know the methods to work on it.. I am using ENVI for this.
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TIMESAT input image requirement?

I tried to work on TIMESAT but always facing a problem. Here is the method I have used. Seems correct, but I get a warning at the end. I have created a NDVI file from ENVI 4.8 >> Transform >> NDVI ...
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96 views

Flow accumulation raster loading in QGIS 2.4.0 with null values (but flow direction loading ok!)

I have been tasked with creating an open-source hydrology dataset for a community group. To do this I have exported the flow direction and flow accumulation rasters from ArcMap as TIFF files and then ...
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82 views

Postgis Raster Unions Color Issues

Can someone explain to me what I am doing wrong here as I think I do not properly understand postgis raster bands. I have a set of geometries that I want to merge with a raster and created a raster ...
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122 views

GDAL WMS in QGIS 2.4

I'm trying to add in QGIS a layer shown here : propluvia When I watch in my console I see this request corresponding to the layer I need. The server is not able to respond to a getCapabilities ...
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143 views

Mapnik PGRaster Plugin creating 8x8 tiles with visible boundaries

I have used the latest addition to Mapnik PGRaster plugin (https://github.com/mapnik/mapnik/tree/2.3.x) by Strk(https://github.com/strk/mapnik/tree/2.3.x-pgraster) and merged recently. I am able to ...
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1answer
80 views

QGIS create raster from cadastre (property lot data) polygon

I have a cadastre (property lots) polygon dataset of a region. Have used rule-base style in QGIS to show different groups of properties in the dataset classified based on their property lot size (ie. ...
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1answer
73 views

How to crop a vector shapefile according to raster?

I am trying to clip a vector shapefile- points according to a DEM in QGIS. I used GDAL function and polygonized the DEM. Then I ran the Vector-Geoprocessing tools-clip in order to crop the vector data ...
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136 views

Finding coordinates of the image corner

I have a .bmp image with a map. For creating image i used a Ingeo 4.4 and function MakeImage() What i know: Height an Width of bmp image dpi Map Scale Image Center's coordinates in meters. What i ...
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83 views

Multiply Rasters with Scalar Numbers as Input in QGIS Modeler

I built a little model in the QGIS modelbuilder which uses the raster calculator with the command gt(a,threshold) I need to run the model with varying thresholds from 2 to 30 so it would be ...
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1answer
123 views

Problem with batch mode Saga Raster Calculator

I have to do a couple of raster multiplications for which the batch mode would save me a lot of time. But the only thing I get are rasters that contain nothing but nan values. If I multiply the ...
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137 views

Easy way to extract raster cells OUTSIDE a vector (Mask) layer in QGIS?

I have a raster file but am only interested in the cells outside a certain polygon. This polygon is very iregular and scattered across the raster. Is there any easy way to extract only the cells ...
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1answer
43 views

Deleting vector lines beyond image extents using QGIS?

I am using QGIS 2.2 I have one vector line layer (roads) that stretches beyond my base image (see below). I wish to have the roads "clipped/trimmed or deleted" right at the edge of the image's ...
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1answer
96 views

How can I shift raster layer for making cloud-shadow mask?

I want to make cloud shadow mask in QGIS. I have raster cloud mask and I have to shift it by X,Y coordinates. Is there any easy solution?
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146 views

PostGIS Raster functions not working

Hopefully I have a simple question that I'm not phrasing correctly in google. I'm trying to learn about storing and producing rasters in PostGIS. There are tons of examples and documentation online ...
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83 views

Speeding up loading raster

I georeference a tif image and then I clipped that image in a mosaic. I did a index of these images but when I load them is very slow(7 seconds or more to display the first tile). How can I do to go ...
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174 views

Correlation between point feature (disease) and elevation

I have a problem! How can I calculate the correlation between point feature and Dem raster? Hypothesis: disease prevalence in high altitude is more than low altitude. I must do this in ArcGIS 10 and ...
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65 views

Determine changes in land cover of isolated features over time?

I have a a study area of 2 Landsat scenes from 2013 which were classified for a specific natural community, and these areas have been isolated and extracted and digitized into vectors so that they can ...
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1answer
186 views

Iso Cluster tool in script failing to open clip raster

I have been coding in Python for only a few months, so maybe I'm just overlooking a minor detail as a newbie. I have written the script below for a class project. It is supposed to clip two rasters, ...
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129 views

Raster Calculator

I have a slope dataset. How do I calculate the real surface area for this slope dataset using the raster calculator. This is the example I was given: orthogonal area of a raster cell in square ...
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Polygonize Missing Polygons

Polygonize is not capturing all of the pixels in an image that has been converted to 0s & 1s. The pics below show -original geotif -geotif recalculated to 0s & 1s -polygonize output As the ...
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Conservation International Hotspot Data

I am creating a Heat Map and need Conservation Internationals's Biodiversity Hotspot Data in GIS form. I have tried to find the data online, but have since been unable. Where would I be able to find ...
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180 views

Adding shapefile elevation data to dted

I am a newbie to QGIS. Currently trying to augment a dted raster value file with vector shapefile(polygon) containing height of buildings. Have converted the shapefile into raster via rasterize ...
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222 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 ...
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111 views

GeoTIFF Mosaic/Crop/Translate in QGIS?

I routinely have to mosaic multiple GeoTIFFs together, extract a rectangular area, and save that area as a JPG with a world file. Typically I've been using commercial software for that (Geographic ...
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36 views

Weekly raster data for temperature and precipitation in US

I am looking for weekly raster data for US for temperature and precipitation. All the major datasets PRISM, WorldClim etc. are either on a monthly scale or daily scale. I was wondering if anyone has ...
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41 views

How can I preserve image quality when combining aerials of different resolutions?

I have two different rasters that were flown at different times during the same month. One has a resolution of 4-inches, the other has a resolution of 6-inches. Using ArcGIS tools, how can I combine ...
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247 views

Is there a Raster2pgsql GUI?

Has anyone ever attempted to create a raster2pgsql gui (like the shp2pgsql gui). As I am sometimes lazy to use command line, this could be a very nice to have.
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122 views

Gdal_translate and transparent rasters in PDF

I am trying to make an application that creates geospatial pdf's from my website, but I am encountering problems with Gdal_translate and transparency of rasters. The setup that I am working up ...
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107 views

How do I replace cell values of a raster using values of another raster with differing extent?

I have two rasters (raster1 and raster2). The raster1 extent is smaller than raster2. I want to replace the value of raster2 pixels using raster1 pixels. How can I replace the values?
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How to select a specific area (in a polygon form) determined by some value range in a raster band?

For example, I want create a vector layer with polygons that represents all areas where the elevation is between 500 and 600. Someone has any idea to help me? I'm using PyQgis 2.2.
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rasterize a geography polygon using postgis 2.1

I am still bit new to Postgis 2.1. I am trying to rasterize a polygon, meaning that I have a polygon of Syria and I want to create an empty raster that contains the shape and geography reference of ...
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73 views

MapServer: UV_ANGLE not calculated correctly?

I'm following this example given on the MapServer website. But the angle of the raster is incorrect: The data is my grib files is correct, and should not yield these perfect opposite directions. ...
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PostGIS raster connection is not closed by MapServer

I'm using PostGIS raster in MapServer like this: TYPE RASTER DATA "PG:port=6432 dbname='mydb' user='postgres' password='1234' schema='public' table='truemarble' mode='2'" PROCESSING ...