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

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15 views

the layer attribute table is not consistent with the pointvalue

The point value of my grid is right, but the output value ranges from -2147483648 to 2147483647. I haved tried to recalucate statistics, but it didn't work..
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1answer
1k views

How to resample GeoTIFF images to the same resolution?

I have two geotiff images that I would like to resample the same resolution. If I use ArcGIS this would be easy to do. But using QGIS I don't know how to do this. Some help will be very appreciate. ...
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0answers
193 views

How to add new raster store and publish for ECW fromat in GeoServer 2.4-RC2?

I am using GeoServer 2.4 RC2 and Tomcat7 on windows xp OS. I have extracted the gdal-data.zip (2.4.0) and geoserver-2.4-SNAPSHOT-gdal-plugin into Tomcat 7.0\webapps\geoserver\WEB-INF\lib. Now ...
2
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1answer
1k views

Convert 32 bit image to 8 bit image in QGIS

I want to convert my images from 32 bits to 8 bits. I'm using otb to calculate texture and the raster output is on 8 bits, I'm going to use this information as a layer stack for my multispectral image ...
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0answers
203 views

validating the calculation of slope from DEM

my purpose is to calculate and validate slope in percentage of southern california using DEM and landsat data. step 1)i used a DEM file and changed with the float type file to integer type step 2) i ...
2
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0answers
85 views

Can Esri ASCII Input files be Aligned with Track Heading in QGIS?

Using QGIS to input Esri ASCII data files, I uploaded many small files, each file representing a second of data: 16 sensors X 25 lines. Each file uploaded creates a small rectangle on my larger map ...
2
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1answer
266 views

Raster format with rotated cells - no resampling

Is there any way to rotate a raster w/o resampling? I am aware that rasters are always 90 deg perpendicular grids, but is there any file format or methodology that allows for a diagonal raster - one ...
3
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1answer
171 views

How to import ESRI Ascii format into GRASS?

I need to take a set of datafiles, generated by our sensor system that reads GPR (Ground penetrating Radar) deviations over a surface as we drive along. I have discrete readings from a set of sensors ...
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6answers
916 views

How do I iterate through every cell in a continuous raster?

See this link for more details. The Problem: I want to loop through a continuous raster (one that has no attribute table), cell by cell, and get the value of the cell. I want to take those values ...
4
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2answers
229 views

Creating planes, eg roof surfaces, from LiDAR/DSM data

Bit stuck here, Im capturing the area of roof tops of buildings from a DSM (derived from LiDAR data) which has not been much of a problem. I can then also derive angle, hillshade and aspect but it ...
2
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1answer
248 views

Split single raster within multiple polygons

I have a raster ('slope') which content only one attribute in the table. On the other hand I have a feature which content several polygons (catchments) in the attributes table. I would like to obtain ...
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1answer
156 views

How to import and patch multiple ASTER files in QGIS?

I'm a new user and just began with GRASS, where I learned to import 30x30 resolution ASTER files and then patch them (the six I'm working with) into one map. On QGIS, it doesn't appear that there's a ...
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1answer
1k views

Convert vector data with irregular points (no grid) to raster with QGIS?

I am aware that how to convert a vector layer to a raster layer is a quite frequent problem and that there are many questions and answers dealing with it. However, none was helpful concerning my ...
0
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1answer
53 views

USGS FLT Hdr file interpretation

I have a legacy program that attempts to read USGS 1/3 arcsec data. When I compare results to GDAL, I find that the lat/lon to pixel conversion is off by 1 line. The reason (I think) is because the ...
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1answer
534 views

How to “spatially normalize” rasters of different extents to sum values of overlapping cells

How do I add rasters together that are of different spatial extents? I have many, many features that overlap over a large area (entire east coast) and I am looking to sum them "stacked" where they ...
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2answers
162 views

In grass v.drape works with points but not lines

I got an elevation raster map which I interpolate from a point cloud with v.surf.bspline. Then I digitize a couple of points in a new vector layer. With v.drape I'm able to get a height from the ...
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1answer
128 views

How to delete raster dataset from sde base programmatically

I use sde database, registered with ArcGis Server 10.1. Sde connection is direct. Database container is postgres. There is a raster dataset in this sde base. I can open this sde database ...
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1answer
36 views

calculate the needed space for a raster pyramide withqgis

how can i calculate (or where can I find information to calculate) the required disk space for a raster map of 36GB which should be in a pyramide of 10 levels ? Regards, D3
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1answer
234 views

Problem with converting rasters to arrays and adding them to main array, then converting to raster via NumPyArrayToRaster : output is NoData values

I have a process that aims to loop through a list of rasters (testing with only 3) covert each raster to an array, add the array to an existing 'template' array, then save the final array back to a ...
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0answers
110 views

Corrupted rasters after import into ArcGIS FGDB

I have been seeing a number of corrupted rasters recently after importing them into file geodatabases (FGDB). The image below left shows a .tif prior to the import, while the image to the right shows ...
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0answers
159 views

Modifying Raster Layer with Python Console

Forgive me if this has been asked somewhere else. I am looking for a way to edit a raster file which has already been loaded into QGIS through the python console (i.e. I would like to edit the raster ...
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2answers
736 views

How to extract subdataset from HDF raster?

I am trying to extract a subdataset from HDF raster. Later on, I intend to make operations such as mosaicking and extracting raster averages from the extracted subdataset. The following code is ...
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2answers
636 views

Similarity between two raster maps

Having two raster maps as the examples below: We are interested in evaluating their similarities. As shown, they are not fully overlapping. We guess one way is to clip small one area from the ...
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0answers
293 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
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1answer
100 views

RFE raster images datum conflict

Im using ArcGIS 9.3. I've downloaded RFE images from FEWSNET. And im trying to load them on ArcMap, to clip them using Mozambique's shape. But as the RFE images related to Southern Africa come with ...
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1answer
82 views

Update Grid cell value with Point attribute

I have a 4km gridded dataset with each grid cell value as a measurement of precipitation. I would like to update it with a point shapefile of more precise precipitation values. Aside from ...
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1answer
113 views

Raster Dataset projection problem

I have a problem connected with my Raster Dataset projection. Two of its bands cannot be shown in some scale - only under 1:1500, when I use 'Zoom to raster resolution' option. Histograms for all 3 ...
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2answers
70 views

v.what.rast trouble in GRASS GIS 6.4.2

I'm facing a problem using the v.what.rast comand. I'm trying to update the vector "canali" which represents some streams, with the slope value for every single point of the lines. The slope values ...
0
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1answer
171 views

GRASS 7 - raster calculator “and”

I am struggling with one thing in the raster calculator in GRASS GIS 7: I want to create a raster_b from raster_a, with raster_a values between >=-0.15 and <=0.15. The raster containing values ...
7
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4answers
287 views

How to compare areas in scanned historical land use maps

I am a relative beginner to using GIS, and am running QGIS 2.0.1 in Linux. I have two historical maps which I want to analyze, that show land use patterns in the same area at two different moments in ...
5
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2answers
788 views

How to calculate the number of cells with a given value?

I have a raster file where all cells have values between -3 and 7, no data value is -9999. Have can I calculate the number of cells with a specific value e.g. 6? Can I use the calculator?
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1answer
835 views

How to change the pixel value of a raster dataset which overlaps a polygon featured shapefile in ArcGIS

I have a raster data of 1992 and a 'shapefile' of Los Angeles county. I want to reclassify the pixel value of the raster data set to 'no data' or zero in the region where the raster and the ...
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0answers
61 views

grass region resolution error

I am working on a raster, but I can't set a correct region for it. In the Set region to match this raster map field, I select my raster map to change current region, but its resolution does not ...
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1answer
128 views

create POV-Ray image from DEM-file in grass

I am working on r.out.pov Tool of grass 6.4 creating a POV-ray(beautiful 3D) image from an elevation raster. You can see this link for more information about 3D analysis of GRASS. r.out.pov manual ...
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1answer
321 views

Creating Contours from a Classified Raster - ArcGIS

I have a group of classified raster files, showing point densities at 3 intervals. I want to create contour lines based on this data at these same intervals. I'm guessing this should be fairly easy, ...
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1answer
346 views

Basic raster map questions

My bigger problem is to convert a raster map to polygons. I've found some questions that give info and I'm trying to use GRASS GIS as part of that. However, I'm having some basic problems and I can't ...
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3answers
336 views

Where to obtain free 15m ASTER image for New Mexico?

I am looking for a free Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image that will let me to perform NDVI for the pilot crop health/soil moisture that can go as far back ...
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0answers
107 views

How can I create a multi layer exportable file (.xcf .psd) from multiple raster image in QGIS?

I have many raster file of the same zone but in differents spectral bands. I would like to create an exportable file of a small portion that can handle different layers. So in practice I would like to ...
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1answer
502 views

Trying to run raster calculator to build an expression for ls factor

I am trying to run a raster calculator, but it failed. I believe that ArcGIS 10 does not understand when I use the variable resolution. What do I need to put in its place? I took the equation from ...
0
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2answers
170 views

How to average a set of n rasters using gdal or other GRASS module? [duplicate]

I need to average a set of n rasters using gdal or some other GRASS module. What command exists for this purpose?
4
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1answer
94 views

Rasters stored in folder: Is there a limit at 5,000?

I have a python script that creates batches of ~6,000 cost distance rasters. These rasters are intermediate data that will be summarized in another process. Output is stored in plain old folders. ...
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40 views

How to select raster layers for averaging based on values in another layer?

I wonder if anyone have some ideas about how to solve this geoprocessing situation: 1: I have a raster layer called mixlyr_apr (representing depth values) 2: I have a series of raster layers called: ...
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1answer
279 views

Having issues removing white background from Raster images

I've got an issue with 4 raster layers that I have converted from kml files into layer files. It would only allow me to convert them if I used ground overlay and now the 4 raster images are ...
2
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0answers
58 views

Copying an entire column between layers (tables)

I have a raster layer with probabilities as values and I process them using the Spatial Analyst extension. After the processing the values are modified, however I would like to also have the original ...
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1answer
165 views

GRASS GIS related issues! [closed]

(1) How to create a multiband raster from a set of single band rasters (except when somebody talks about doing a r.composite). I attempted creating a raster3D and it turned out that it is not ...
2
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1answer
1k views

Spatially join large raster to polygon shapefile

I have a large raster file with elevation data. From this raster, I would like to infer the average ruggedness for different geographic zones (like countries). I have the "countries shapefile" as a ...
3
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1answer
311 views

Area precipitation using IDW

I'm having the following problem with IDW automation. I have a catchment and several gauging stations measuring daily precipitation amounts. I would like to interpolate the precipitation amounts from ...
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0answers
108 views

convert vector with multiple attributes to multiple rasters

I have a vector polygon feature with multiple attributes/fields. Ultimately, I want to convert it to a raster 'stack,' whereby each of the attributes/fields will be a different band of the raster ...
12
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4answers
7k views

Loading a raster into a PostGIS 2.0 database on Windows

I'm trying to figure out how to load a raster into a PostGIS2.0 database (I have asked previous questions on this topic here and here). I am trying to use the raster2pgsql.exe program provided with ...
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1answer
136 views

ArcGIS raster data - Group statistics for classification

I'm trying to figure out how to classify a group of rasters. These can't be joined as they have overlaps which must be kept. I was wondering whether there's a way of obtaining grouped statistics - eg ...