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

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Strange black pixel on edge when generating with gdaldem -hillshade

I'm getting a strange result when I'm generating an hillshade with the gdaldem hillshade command. Here is my command (see the compute_edges parameter): ...
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2answers
857 views

How to clip an Openlayers OSM Background to a Vector Boundary?

I'm new to QGIS. In my project i have two layers: one is my vector (city boundaries) and the other is the OSM (obtained with the plugin). How can I cut the OSM along the edges of the vector? I want to ...
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1answer
116 views

Which File to load from National Hydrography Dataset?

Start-over beginner here. I'm using QGIS 2.0 on MacBook with OS X 10.8.5. I downloaded a National Hydrography Database file. Unzipped, it is titled NHD11032_NM.gdb. I try to add the layer as a vector ...
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101 views

Two r.mapcalc calculations return a much bigger raster cell size than the input raster

I tried the following calculations with a GeoTiff sample, having a cell size of 25m: Calculating the togographic exposure (TOPEX) and estimating the mean topographic curvature Both, the resulting ...
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1answer
82 views

Raster to Surface

I have a raster and I have been asked to modify some pixel values in it. Is there an open source way to do this? I would guess that I have to create a 3d surface, then manipulate the surface, then ...
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2answers
891 views

Calculate area covered by a particular raster layer within polygons in QGIS

I am trying to extract information on vegetation cover within a set radius of point locations (my sites). I have succeeded in creating a new vector layer of circles with a 5 km radius around my sites. ...
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143 views

Whats the best way to create bathymetric contour lines?

I have a raster dataset with both Topographic and Bathymetric stored in it. What is the best way to create exact contours of the lake-bed? This becomes tricky when I want to make the contour for depth ...
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2answers
516 views

TIFF/Raster to Point shapefile question

Apologies in advance if this question is incredibly basic, but I've been googling around and I just don't know where to start. I've downloaded some nighttime luminosity data from NASA, and the data ...
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301 views

Hillshade tool in ArcMap returns terraced, pixelated image

I am applying Hillshade tool (ArcMap 10.1) to SRTM in Caucasus Mountains (border between Russia and Georgia). It gives me weird image with 'terraces' (see attachment). I reprojected SRTM from WGS-1984 ...
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2answers
280 views

How to identify valleys on DEM in ArcGIS 10.1 [closed]

First, What is the best and easiest way to identify valleys in a DEM raster? Second, how do you create a least-cost pathway for each valley in a region based on low angle slope and proximity to ...
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1answer
97 views

How to get Name of IRaster object using ArcObjects?

I have an IRaster object as output from a function. I need to be able to get the name of that raster. Is there a way that I can do that? I know that I can't mask an IRaster as an IRasterDataset. If I ...
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1answer
112 views

Retrieving raster/coverage width and height in pixels from GeoServer

Is it possible to retrieve the original width and height in pixels for a coverage in GeoServer using either the Python API or REST? I could not find anything in the documentation regarding how to ...
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3answers
2k views

Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
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1answer
140 views

GeoServer raster tiles are individually contrast-balanced: how to turn this off?

I'm running GeoServer locally as a servlet (in JBoss), and I'm serving a GeoTIFF file through the WMS protocol. In a webpage running an OpenLayers map, I have the GeoTIFF-WMS layer overlaid above an ...
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1answer
160 views

R - Efficient way to segment rasters into sub-regions and sample… without using extract()

My question is: Is there a more efficient way to sample from a sub-region (defined by a shapefile read into a spatial object) of multiple rasters without having to use extract() for each region on ...
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1answer
880 views

extend the size (area) of raster

My problem is that I would like to multiply two rasters using raster calculation tool. Both rasters have values 0 and 1, but the covered area of first raster is bigger (100 x 100 miles) then the area ...
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2answers
30 views

working with hydrography raster the cost array ignores the end of water

We have our maps laid out using hydrography maps from NOAA. We had to run the graphics through several steps to create the water feature raster. I have a process that pulls in that raster, sets a ...
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2answers
129 views

How to automate creation of toe of slope from DEM?

I was looking for an automated process to "identify" the toe of a slope from a DEM and ran across this ESRI thread and technique: I am at Step 7 but have no idea how this is accomplished. I get it is ...
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1answer
104 views

How to calculate the sum of all cells in a raster layer upstream of a specific point?

I have a rainfall map which covers large area. However, I'm interested in the total value of rainfall over a specific subcatchment. If I don't have the shapefile which defines the boundary of this ...
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1answer
1k views

How do I fill gaps in a raster to zero value cells?

I am trying to add some forest elevations to a DEM using ArcView. I have converted a polygon feature class of a forest into a raster with the same resolution as my DEM. Then I reclassed the forest ...
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2answers
285 views

Rasters added to mosaic dataset only display at large acale

I have a set of 357 rasters in .jp2 that I've added to a mosaic dataset. All but 7 of them display properly, but the 7 only display at larger scales, around 1:6500 and under. I've tried adding them ...
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1answer
302 views

If I convert a TIN to a raster in ArcGIS will results from the two versions of the surface be comparable?

I have converted a TIN to a raster. I found that the top of a bund wall shifts laterally in position between the TIN and the raster into which it has been converted using the TIN to raster tool in ...
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1answer
425 views

Use of Raster Calculator in ModelBuilder

I have the following equation: 3000*(1-exp((-0.000664)*input raster)) I want to make a tool to use this equation on raster images. I want to do this with the Raster Calculator with the help of ...
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1answer
57 views

Can I export an imagery directly to a geo-referenced raster form File|Export Map in Arcmap?

While using File|Export to export an imagery to raster, is there a way to have it geo-referenced in a way that if I load the exported raster into the map, the image sits exactly in its place without ...
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284 views

converting vectors to raster (burning streams)

I converted my stream vector to a raster file (using polyline to raster conversion tool). I anticipated that I would get a No Data row in the raster file attribute table, so that I could use a ...
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1answer
3k views

Is there a way to export online ESRI basemap layers to raster?

I have been working on polygonizing the vegetation areas in some counties from imagery. When I have the mosaic raster locally I can easily get the polygons using Image Classification Toolbar. But when ...
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1answer
60 views

How to choose an area (of mxn metres) within a raster that have values above a certain range

I've got a raster of concentrations of iron on Mars and I want to be able to choose several areas of either m by n dimensions in metres, or just any area in m^2, that encapsulate regions that have ...
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2answers
3k views

How to make RASTER from irregular point data without interpolation

I was trying to make a raster image from an irregularly spaced point database. The data looks like- > head(s100_ras) x y z 1 267573.9 2633781 213.29545 2 262224.4 2633781 ...
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1answer
1k views

How to perform a Cost Path analysis in ArcGIS 10.1?

Is it possible to model the easiest pathway through a landscape between many points (rather than just two)? I want to carry out a cost-path analysis, I would like to display the easiest pathways ...
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1answer
125 views

gdal_rasterize using a “string” as src_datasource

I would like to use a string as src_datasource for gdal_rasterize program. Is it possible to use something like a WKT definition to translate a single point to a raster? Somethink like ...
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2answers
2k views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
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81 views

Color blending/compositing in web mapping frameworks?

The color/layer blending capabilities of QGIS 2 produce marvelous results. Blended rasters are especially nice to look at. Blending is, to me at least, a better way of combining layers than mucking ...
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3answers
507 views

Cache generation failed. Progress gets stuck at 0%

I'm trying to publish a map service containing a large .tif raster (48GB). I managed to publish a small cached raster successfully (for testing), but when I tried to publish the large one, the cache ...
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1answer
232 views

Wrong values in Feature/Point to Raster

I've got an XY dataset that I'd like to convert to a raster, based on the ETrel_whol field. The ETrel_whole field includes NaNs and ranges from 0-1. I would like to convert this to a raster, with a ...
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1answer
90 views

How to build and pass remap for floating point raster without getting Reclassify ERROR 010255?

I am receiving the following message when executing my python script: ERROR 010255: String remap must be used with a string field. My input raster is floating point and I would like to ...
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1answer
101 views

How do I create smaller maps for publishing from multiple tiles representing a large map using QGIS?

I am completely new to cartography and QGIS - I'm a writer, editor and acceptable designer (Adobe Creative Suite). I wish to produce PDF tour guides featuring maps that display a route. One version ...
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3answers
1k views

Merging hundreds of Aerial Photos into one big file?

I have tried to merge my 405 Aerial Photos into one. I have FME and ArcInfo 10.0 at my disposal on Windows 7 64bit. I have tried the following: create a mosaic; export all images from a ...
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37 views

Warping Rasters in QGIS

There seems to be a bug warping rasters in the new QGIS version 2.0 When you have to option of target and Source SRS, the Coordinate reference system does not get automatically writen into the box ...
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1answer
260 views

Tabulate Area for large datasets

I have been struggling trying to use Tabulate Area in Arc 9.3 for a large raster dataset. I have one raster with 8 land uses and another vector layer with zones (which I converted to a raster with ...
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109 views

Mann-Whitney U test for rasters

I'm doing a Mann-Whitney U test to compare two very large samples (sample size 1 = 13250; samlple size 2 = 38871) originating from a shapefile with 52121 features. I know t-tests are not recommended ...
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2answers
1k views

Efficient way to handle NA values from analysis in R with Raster

I am not 100% sure if GIS is the correct stackexchange for this, but here we go. A problem I have been bested by: I have a raster layer of approximately 240 million cells. It could be a DEM or ...
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1answer
966 views

Service published but cache generation failed on ArcGIS Server

I am trying to publish a map service containing a cached raster layer on our ArcGIS Server Enterpise 10.1. I analyze the map service before publishing and no error. The error I get when publishing ...
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1answer
90 views

resampled thematic map accuracy

I've generated a map of ecoregions based on some environmental data using a semi-supervised classification where I combined a statistical clustering with random forests to generate my map. I created ...
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2answers
495 views

How to de-noise a DSM

I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
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2answers
196 views

Problem overlapping shapefile and vector in R

I want to plot a shapefile over a raster file in R but I can't make them overlap perfectly: the raster appears to be rotated of few degrees counter-clockwise. Is it a problem with the projection? ...
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117 views

Calculate surface elevation from DEM of pit and known volume with which it is being filled

I am using ArcGIS 10.1. I have a DEM of a pit. I have a known volume of material that I want to put in the pit. I want to know what the elevation of the flat surface of this material will be ...
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1answer
265 views

Does ModelBuilder need to use variable to define projection and then re-project?

I am trying to build a Model in ModelBuilder to create two different process raster datasets: One set is to define a raster dataset to set a WGS 84 projection; and then the second set is to take ...
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1answer
2k views

How to Build Raster Attribute Table from .tif with pixel type of float or double?

I have a raster with the extension .tif. It's a subset of 87x87 pixel with values from some 6,66 to -4,27. If I right click on it there is no Attribute Table available. However, I can change the ...
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1answer
276 views

How to create Series of Rasters that displays Standard Deviation from Mean?

Cell statistics question for you. I have 100 rasters of raw rainfall data in which the pixels each represent rainfall for that particular pixel on the landscape for a single year during the 100 year ...
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5answers
983 views

How to export raster from PostGIS enabled DB as GTiff with gdal_translate

When I want to export a GTiff from my PostGIS DB with this code: gdal_translate -of GTiff PG":host='localhost' port:'5432' dbname='landslide' user='postgres' password='pass' schema='public' ...