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

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Issues calculating range with QGIS 2.0 raster calculator

I would like to calculate a simple range using the QGIS 2.0 Raster Calculator, but am getting strange results. I believe I am not using the correct syntax. To get all values between .003-.5, I ...
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5answers
313 views

Greyscale Raster (tif) in ArcMap

I've searched all over google and have found nothing. I want some tiff files I have in ArcMap to be in greyscale with the rest of the layers in colour, similar to the style override > greyscale option ...
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42 views

Coordinate system ID ArcGIS

I have satellite image files with metadata generated from ArcGIS: Raster Download Information Coordinate system ID WGS84: 4326 Top edge WGS84: 35.0003681085064 Degree Bottom edge WGS84: ...
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46 views

Conditional statement, apply different equation based on raster value R

I am trying to find the best way to apply a set of equations to a raster conditional on values in a separate raster. For example, suppose r1 has the values of interest and raster 2 (r2) is a raster ...
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36 views

Convert a lat, long, value table into a raster

I would like to to convert a table with latitude, long, and a value into a raster. My file looks like this: X Y Z 32.85138942 -6.643054718 0 32.85138942 -7.059721474 1004 32.85138942 ...
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67 views

QGIS 2.8 Convert a vector to a raster layer

When I change a vector layer to raster using raster button->converse->Vector rasterization in QGIS2.8. I get only a black picture. Why is that so and how can I convert a vector layer to a raster ...
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1answer
30 views

Loading Raster using QGIS API in Windows

I am trying to develop a C++ application using QGIS. I have to load a tif file and show it. First I wrote an app similar to samples on the internet. It works on Linux, but it does not work on ...
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2answers
28 views

How to compute climatology of 3 days moving averages for rasters pixel by pixel?

I have one year of datasets that I want to compute the climatology of 3-day moving averages and then I subtract this climatology from the original values for each pixel. example: # Set up the ...
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7answers
4k views

How can I align two non-coincident equi-resolution raster grids?

I have two rasters: a digital elevation model (DEM) and a Landsat band. The grid resolution of both is 30 m, but the grids are not coincident (see image: the dark raster on top is the DEM; the light ...
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2answers
131 views

QGIS raster calculator using abs() function

Is it possible to use the Abs() function in the raster calculator in QGIS? I've tried it, but it didn't work.
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1answer
53 views

Qgis raster calculator not giving output

I want to calculate some result using QgisRasterCalculator and using the code mentioned below.Problem is i am not getting any output raster also if i use this formula in raster calculator it gives ...
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86 views

Why are raster z-values changed when reprojecting?

I have raster data with height values (z). When I try to reproject/warp the raster to Gauss Kruger 3, the z-values are changing (several meters). (The data is already GK3, but I have to reproject ...
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21 views

Creating raster from points that conforms to a reference geometry using PostGIS, python, QGIS

Please forgive my ignorance, I'm fairly new to processing GIS data. My bread and butter is statistics but I'm now working on a project that requires more data preprocessing and cleaning than I've ...
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1answer
97 views

Unsupervised classification in QGIS

I was trying to learn unsupervised classification in QGIS 2.6 following the tutorial video: https://www.youtube.com/watch?v=mI80eENtWSE When trying myself, clicked Run during the process it shows the ...
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2answers
4k views

How to visualize grd files in QGIS?

How to visualize grd files in the software QGIS?
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30 views

Overlay polygons on raster in different projections

I'm overlaying polygons on a raster to get the average value inside the polygon (using SAGA->Shapes-Grid->Add grid values to shapes in the QGIS Processing Toolbox), using a geographic and a ...
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24 views

Weighted Overlay not showing all values

In a ModelBuilder, my final step is to add a weighted overlay at the end. I have 4 reclassified layers as the input, all equally weighted and all contains values 1-10. However, when I run the Weighted ...
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1answer
360 views

USGS GeoTiff extent via GDAL

I have 2006 land cover GeoTiff from the USGS site (for a county in VA, USA). The projection is Albers Conical Equal Area Units. The download came with an HTML metadata file that tells me the geo ...
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1answer
35 views

QGIS how to save loaded min/max values for raster layers?

I am working with many layers. Each time I open my saved project, I must reload the min/max (properties/style) values. Is there a way to turn off the default 2% cut?
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36 views

Project Raster Data Loss - 2 Billion People

I am using the SEDAC/CIESIN raster data for population counts. This data is in WGS1984, and I want to project this data to a Fuller projection. After running through "Project Raster" in ArcMap 10.1, ...
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8answers
9k views

How do I create a shapefile showing footprints of Rasters?

I have around 1,000 satellite images in tiff format, and I want to create a shapefile which will serve as an index to the rasters. This is something similar to a raster catalog, but I do not want to ...
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1answer
40 views

Creating an R factor raster in RUSLE Soil Loss equation with multiple input rasters

I am attempting to obtain the rainfall erosivity "R" factor for the RUSLE Soil Loss equation using rainfall PRISM 30 year history data. I have both monthly and annual data that comes into ArcMap as ...
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2answers
91 views

Multiply Rasters from two subfolders

I have two subfolders with Rasters named with the same parameters. I am trying to figure out a way to Loop a multiplication of each raster into a folder with its pair of the other subfolder. Looks ...
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26 views

Raster Calculator or Local-Combine tool? (in ArcPy)

i have 3 classified rasters and i wanted to use the following query from r. calculator: (rclslope>=45) & (rclmosaic>=2000) & (rclfocal>15) to arc.py how can i write it? Is it ...
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2answers
96 views

How to load projection along with raster in R?

Why the operation myraster = raster("test.asc") does not load the associated projection file test.prj located in the same directory as test.asc? Does raster() need a specific argument? It seems ...
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46 views

Zonal histogram for each region (row) in a polygon (table) with python script

I have DEM.tif (symbology uses equale interval - 100m) and a polygon file (regions.shp) with many regions (names are defined in 'reg_name' column). I would like to use Zonal Histogram to produce ...
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106 views

Reprojecting a raster image using gdalwarp

I am trying to reproject an ECW Orthophoto from 25830 to 23030 srid. I tried the following but I am getting an error: C:\Program Files (x86)\FWTools2.4.7>gdalwarp -s_srs 25830 -t_srs 23030 ...
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38 views

OpenLayers/Geoserver - can I create a tiled, zoomable raster layer?

Still a relative newbie with Geoserver and OpenLayers. Developing an application with Geoserver in the back, OpenLayers (3.0) in the front. I have a requirement to display imagery on top of a base ...
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1answer
32 views

how can I make “weighted sum overlay analysis” in QGIS? Ordered Weighted Averaging manual may be useful

I have weighted raster data converted from polygons with different categories. I have ArcGIS with 3D Analyst extension, unfortunately do not have Spatial Analyst, and I would like to use QGIS to make ...
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16 views

Reprojecting a ECW raster with fwtools [duplicate]

I have a ECW Orthophoto and i want to repoject it from 25830 to 23030 srid. I haven´t found a free software to do this but i heard of a command line utility called FWTools that could do the job. I ...
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59 views

How can I identify lines that intersect a certain raster layer area?

How do I identify certain roads ( of a line shapefile) that intersect with a layer that is produced from the reclassify tool (for raster data)? I am trying to identify which roads specifically are in ...
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25 views

Aspect Patch Count

I am using ArcMap to create aspect maps. I want to find the how many different directions the land faces (total aspect patch count) with continuous patches greater than three. So for example I want ...
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3k views

How can I compute raster pixel width and height given raster bounds, row count, and column count?

Restated, how do I convert arc degrees to meters? For example, I have an elevation data raster that has the following metadata: WEST LONGITUDE=64.97798789° E NORTH LATITUDE=33.02003415° N EAST ...
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30 views

Point to Raster Converting Result

I had a problem with Point to Raster converting result. I had an Excel file which contains x, y and z values. I wanted to create an individual raster data from classified z values so I planned to use ...
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2answers
2k views

Why is Raster Layer not visible?

I have a raster dataset that is not visible in Data View, but it is listed in the Table of Contents. I have tried viewing it in ArcCatalog but it is not visible there either. Is there something I ...
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3answers
248 views

Export georeferenced image from AutoCAD to GIS?

I have an AutoCAD .dwg file that was assembled from scanned maps and is georeferenced. I would like to export it to use as a raster in ArcGIS. What file format should I use, that can be opened in ...
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1answer
338 views

ArcSDE - How to edit mosaic dataset

I have a mosaic dataset (Raster) in an SDE database. As expected, when I click start editing, ArcMap says that I have to do "Register as Versioned" before, but I can't have a mosaic dataset in a ...
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72 views

Numbers containing e in ArcGIS?

In ArcGIS when I try to calculate some raster values or statistics, sometimes I get values that contain e, for example: 1.4e6. What does e mean, and how is it interpreted in ArcGIS?
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105 views

How to effectively merge SRTM 1 arc data?

We have around 1800 1 arc-second SRTM tiles (Geotiff). How to effectively merge all the tiles into one single file ? We are thinking about splitting 100 files per folder and merge them together using ...
2
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1answer
33 views

Create Raster Surface from Points and Equations in ArcGIS

I want to use point data to create a raster surface which distributes the values over space, as defined by an equation, and NOT by interpolating. I have an equation to describe how the characteristic ...
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2answers
112 views

How calculate pixel by pixel the mode (statistic) of multiple rasters (geotiff)?

I have 12 land cover maps, and I would like to calculate the mode to each pixel of the 12 maps (they have the same resolution and dimension). I mean, the final map would be the mode for each pixel of ...
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1answer
110 views

How to perform a non-linear regression pixel by pixel?

Using nlsLM from Package ‘minpack.lm’ is straightforward for a simple example like this: MODEL:y=(exp(a*x+b*z+c)+d)^f x=c(0.5,0.3,0.2,0.4) z=c(0.1,0.6,1,0.9) y=c(0.2,0.3,0.9,0.9) ...
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0answers
25 views

How to avoid a problem of one pixel when doing non-linear regression?

I am ruining a non-linear regression using nlsLM from package:minpack.lm for multiple rasters (pixel by pixel). My initial values may be appropriate for some pixels but not for others.When I run the ...
2
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1answer
34 views

How do I count the number of cells which can see each cell in QGIS

For each cell in a DEM I'd like to count the number of cells which can see it (i.e. direct line of sight) - Can anyone explain how to do this in QGIS? Thanks,
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45 views

Can't import libraries to rsaga

I get this error when I'm trying to import a raster to RSAGA: > rsaga.import.gdal(paste(rast_name, ".tif", sep=""),"RASTER", env= my_env) Module 'GDAL: Import Raster' not found in SAGA library ...
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16 views

Creating a time series from multiple rasters in ArcGIS

I have 10 rasters (10 yearly averages of data) that I've uploaded into GIS. I would like to do two things: Create a time-series of the values of that raster at one specific point within it. Create a ...
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1answer
521 views

How can I save and re-apply symbology properties for a classified raster in ArcMap 10.2?

I have a classified raster which has the desired symbology configured in ArcMap, and I want to apply this symbology to other similar rasters. So I use the Save option on the Symbology tab, intending ...
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3answers
2k views

How to convert raster to point in QGIS

I wanted to convert Raster into Point Vector in QGIS. Is it possible? QGIS have option to convert it into polygon but i didn't found any tool to convert it into point. can anyone help me?
5
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1answer
846 views

Python equivalent of gdalbuildvrt

Is there a way to perform the same task as the gdalbuildvrt utility using GDAL Python bindings? So far I have not found any way to do this other than creating a vrt of a single dataset and manually ...
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1answer
31 views

QGIS Raster Calculator, joining two raster

In QGIS raster calculator I do: Plus (+) And I get: The red circle in the middle is like cut in the result, QGIS it's not adding every pixel on each raster, it makes a kind of ...