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

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Properly placing my raster over a shapefile on my map

I have an ASCII file that I converted to a raster. My heading on the ASCII file is: NCOLS 156 NROWS 720 XLLCORNER -170989.3011812 m YLLCORNER 1417628.464462 m CELLSIZE 1 ...
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179 views

Raster (Tiff) to KML for Google Earth Overlay - QGIS

I am trying to convert some raster files to KML in QGIS for overlay in Google Earth. They are really huge Tiff files as I processed them from 3 meter DEM datasets. I have been searching the web and ...
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104 views

Zonal Statistics for multiple rasters

I'm trying to create a timeseries of raster data (one layer per year) by polygon (Administrative regions). Is there any way in QGIS to perform Zonal Statistics for multiple years (without having to ...
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1answer
30 views

Mosaic rasterstacks based on minimum of certain layer?

I am trying to mosaic 42 remote sensing rasterstacks (with 250 bands) based on the criterion that in overlapping areas, the pixel should be taken that has the most nadir viewing angle Beside my ...
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2answers
65 views

Unable to set raster surface resolution in ArcScene?

I have a 3-band subset of a Landsat image which I want to display in ArcScene (of ArcGIS version 10.2.1). The image is 30 meter resolution and I am draping it on a 25m resolution Aster DEM. But have ...
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45 views

Draw gridded lines inside a feature and generate random points

I have several vectors containing features that originated from a 30 x 30 m raster. I want to generate a grid of lines (fishnet) in all of the features that are more than 30 x 30m. As shown in the ...
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2answers
454 views

ArcGIS 10.3 Build Raster Attribute Table fails for large rasters

I am looking at forest loss in Central and South America within protected and unprotected areas. So I have a binary raster (0 or 1) for forest in 2000 and another raster for forest in 2013. I want to ...
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210 views

Combining multiple overlapping rasters - retain maximum value?

I have 40 overlapping raster grids (derived from flood modelling software) that I want to combine in such a way so as to retain only the maximum value in any of the given rasters at each grid ...
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2answers
204 views

It's possible to use gdal_calc.py with an entire path of rasters?

I try to use gdal_calc.py to scale and transform a time-series of MODIS images. I've done that when i worked with a single image in the -A variable and a mask in -B, but i need to work with a ...
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83 views

Combine several rasters in QGIS

I have a problem combining several rasters into one big raster. Particular annoying is, that I had this problem once before and solved it, but I can't remember how. Unfortunately the other ...
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129 views

Selecting all pixels above a given value in a raster in PostGIS

I have a raster with one band whose value represents the date of the occurrence (a sequential integer). This raster file gets updated regularly, and each time that happens, I need to run a process ...
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1answer
108 views

How to clip a raster by extent using Processing from the Python console?

I want to clip a raster by extent in QGIS with the python console. Here is the description given in the documentation. You have to use the following input parameter: Input layer Nodata value ...
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49 views

'combine' more than 20 raster bands

I have overlapping polygon data that I would like to 'combine' in ArcGIS and I'm running up against the 20 band maximum for rasters. I'm interested in solutions using this basic method with Arc or ...
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35 views

Merging DEM files using PostGIS

I have several DEM files and I want to merge them to create a mosaic. I found the St_Union(raster) or St_MemUnion(raster) functions but I don't know how to use them. Are there any other solutions?
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1answer
94 views

Clipping a tiff image using another tiff image using python

I am working on a code to clip a raster with another raster. I have a forestcover.tiff image and i want to clip it by using other image clip.tiff which extend lies within it. I dont want to use arcpy ...
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32 views

polygonize some raster pixels based on their value in PostGIS

I need to extract and polygonize only those pixels of a raster that have a value (e.g.) greather than 2000.0 The reason is that I wish to do an operation like the following one (which is done only on ...
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1answer
187 views

Combining four shaded relief images into one single image using GIS overlay technique? [closed]

I have prepared four shaded relief images (hillshade) with four contrasting illumination directions 0°, 45°, 90° and 135°. I would like to combine four shaded relief images to produce one shaded ...
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132 views

When subtracting two raster with different cell sizes using raster math, what value is used for smaller cells?

After reading the answer to a similar question (What will happen if we subtract two raster with different cell size using Raster Calculator?), I am still left with a question. When the raster with ...
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2answers
59 views

Averaging a big number of pixels within a several km radius

I work with ArcMap software and now I have the aim to average individual pixels within a several km radius from daily data for at least 1 month. So I made the grid with 4 km step (the step size is not ...
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2answers
752 views

How to create a solar intensity map for a garden plot?

I'm interested in creating a raster surface that depicts the average solar intensity per unit area for a small garden plot. I imagine the inputs into the model would be the following: Plot ...
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57 views

Calculating where the Z values of two rasters intersect

I have several raster layers which are depth horizons, one of these horizons cross cuts the others and I would like to calculate the line along which this occurs. i.e. the line along which the Z value ...
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108 views

Merge raster tiles in PostGIS

I have several raster tiles that are adjacent and non-overlapping, so they form a mosaic. I am trying to merge two adjacent rasters using PostGIS but am getting an error that they do not have the same ...
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1answer
90 views

how to produce a RASTER representing X coordinates [duplicate]

In a journal article I have read that two rasters, representing X and Y coordinates respectively (see attached figure), have been entered as predictors in a GIS-based Logistic Regression for a given ...
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1answer
47 views

Raster appears like polygon in Arcmap

I copied rasters across into my geodatabase for a client but when they open the raster dataset in ArcMap they appear in tiles as shown in the image below. When I drag and drop individual rasters over ...
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142 views

Automate Exporting of Rasters Using Renderer in ArcGIS

It is possible to export rasters in ArcMap by right clicking the layer-> Data-> Export: You can then click 'Use Renderer' check box to ensure the image you export uses the current ...
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946 views

Australian Topo Map GeoTIFFs

Does anyone know if Australian topo map GeoTIFFs are made available anywhere (preferably for free)? LINZ makes them available in New Zealand - http://www.linz.govt.nz/topography/topo-maps/index.aspx ...
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223 views

Does a SRTM DEM image show details such as fields?

I'm working through the QGIS Training Manual where I have a step to get ... ... raster images (SRTM DEM) which cover the region you have selected for your course. SRTM DEM can be ...
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3answers
1k views

How to increase raster extent by filling extent with no data using ArcGIS Desktop without Spatial Analyst?

I am using feature to raster to rasterize water polygons. It only makes a raster the extent of the features in the polygons, whereas I would like it to be the extent of another existing .tif image. ...
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192 views

Importing GPS coordinates to extract multiple DN values in ERDAS

I have a set of GPS points (stored as a csv for now) and would like to import these points to ERDAS to find the DN values associated with each location. I am able to import a SHP to ERDAS but the ...
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37 views

Merging - Aggregation of Rasters

I'm a beginner in Java and a geomatics student. I'am using IntelliJ and I work in Java. I create two raster with the BufferedImage Java class. Raster1 Raster2 These images show for raster1 the ...
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34 views

Transforming climate text data to raster in ArcGIS Desktop?

I have climate data in text files with no header in the format below from Udel's climate program. Each row has a lat, lon, and a temperature for each month (14 columns total) from 1900-2010. I need ...
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2k views

Finding minimum bounding extent of given pixel value within raster?

I am wondering if there is a way to find the minimum bounding extent for a raster with a particular value. I clipped a raster from a global image and the extent is set as the global extent with a lot ...
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73 views

Isolation and interpretation of vineyard multispectral data

I have 3 band multispectral raster imagery over a vineyard from which i have created a number of indices e.g. NDVI. The data is fairly high resolution (5cm/pixel) so shows a lot of along vine and ...
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66 views

Remove Frame Border from USGS scanned images in ArcGIS

I have a couple of USGS scanned maps like I want to remove the frame border from these images so that I can use them in ArcGIS. Is there algorithm or python script that I can run to remove the ...
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23 views

Second order rectification display problems

I'm using GRASS 7.0 to geo-rectify oblique images taken from a fixed altitude and using RTK-GPS data as a GCP (as a vector file) for the process. The survey area is very small and flat, so I'm not ...
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1answer
114 views

Importing large tiled datasets (e.g. Ordnance Survey) into MapInfo?

I am currently using MapInfo and have several large Ordnance Survey datasets, which require updating. They are tiled .tiffs and need to first, be registered as .tab files. Second the .tab files need ...
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1answer
538 views

How to reclassify raster data by their sign?

I want to do the following: I have two data raster sets with different units and values. One results from measured metric data, the other from modelled grid values. What I want to compare is simply ...
6
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1answer
238 views

Add raster paths to shapefile with Python (ArcGIS)?

I have a problem and maybe someone is able to help me or give me some hints how to start. Situation: I have a lot of raster and of every raster I have the center coordinate. Out of this coordinate I ...
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23 views

Add feature data to raster to see where it occurs relative to depths in cross-section?

I have depth soundings in which I have used IDW to generate a continuous raster surface to display bottom contours. A hillshade was generated to display in addition to generation of a TIN and ...
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27 views

Select raster using in line variables

I am trying to select rasters based on an in line variable to insert such raster into raster calculator within model builder. However, when using the select data tool it does not allow for ...
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26 views

Why are my block neighborhoods not square?

I am running block statistic on a couple of binary rasters. Everything seems to be working fine, but the blocks are not oriented with the rumb lines of my projection. They're tilted about 40 degrees ...
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1answer
34 views

Growing error from west to east when overlaying raster and shape

I am using a shape of Austria from gadm.org which I want to overlay with a netCDF file in R. As the netCDF has projected coordinates in EPSG:31287, I have reprojected the shape using FWtools and the ...
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1answer
50 views

How to create a raster of equidistant points with distance in meters using QGIS?

I need a set of equidistant points (like a raster) each in a 1km distance to the next over a certain area, in my case Germany. I know the feature "regular points" in QGIS where I can do just that but ...
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3answers
7k views

How to georereference a TIFF file which has already a spatial reference?

I have a TIFF file of Poland and a self drawn vector map of Poland. The vector map has no spatial information. I am intending to reference the TIFF exactly to the shape of the self drawn map. My ...
3
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1answer
471 views

Can ArcGIS handle missing values to create a contour map?

I am trying to create a contour map for a waterbody. It turns out that in several locations there is no data. I just don't want to use the missing values as zero in ArcGIS because it would create ...
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28 views

How to best import a US Map Schematic?

I would like to use the following wiki US Map schematic as a background to my map work. (http://en.wikipedia.org/wiki/File:Blank_US_Map.svg) It is a .svg file, and GeoReferencer is unable to import ...
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2answers
1k views

How to resample a raster to higher resolution in QGIS?

I'm fitting a SDM using R. A requirement is that all environmental predictor layers have the same extent, origin and resolution. I have high resolution bathymetry data (25m) that I will resample to ...
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59 views

What can I do to reproject rasters without modifying the original values?

I downloaded a series of Landsat 8 Images and I will be using QGIS to process them. The projection of 2 of them are incorrect, so I used "Warp tool" in QGIS to change them. The resulting rasters DO ...
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1answer
64 views

Creating polygon layer from raster

I am using ArcGIS 10.2 in order to create soil management zones for farmers. when I use the raster to polygon tool it creates small triangles out of the polygons and jagged edges that are very ...
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2answers
699 views

ArcPad Raster Not Displaying Correctly?

I have a hillshade that I would like to use as a background in an ArcPad 10 map. I get everything set how I want in in ArcMap and when I export the map to use on my Trimble the hillshade doesn't show ...