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

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Calculating maximum mean temperature of the coldest month with a lists of rasters

I need calculate the maximum mean temperature of the coldest month. I need first select the coldest month in a list and then in this month determine the maximum temperature. I do this: Create the ...
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13 views

Different number of columns and rows in raster datasets

currently I am dealing with the creation of a landuse file. I have geoprocessed a google earth .tiff-file over my DEM and created three polygon featureclasses via the editor tool containing areas of a ...
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fail to convert polygon to raster

I have a shapefile with 520 districts each with a value. I am trying to convert this shapefile to raster using feature to raster tool. Input feature: myshapefile Field: value Output raster: ...
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What kind of raster mosaicking to use in land cover analysis

I have to mosaic two rasters to one single image and then analyse its land cover. Which option to use to avoid seeing a distinct line in the place where two different scenes/rasters are joined? I am ...
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1answer
189 views

Export Multiple Raster Data with custom Cell Size

I Have 172 Raster, and need to change the cellsize. So I use Export Data from TOC and change the cellsize manually (example I want to change it to "3") I tried using this python script to ...
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2answers
407 views

How to remove long linear strips from polygons?

I have a polygon layer representing impervious land cover. This was taken from a land cover raster dataset. The impervious data represents all impervious surface that is not buildings or roads. I ...
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2answers
861 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
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1answer
197 views

How to create a raster with rotated cell orientation from lattice points - ArcMap 10.1

I am trying to create a raster layer from gridded points where the cells have a rotated orientation. Each point is the center of a 1.6 km by 1.6 km cell, rotated to the left. Is there a way to do this ...
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1answer
496 views

How can I get my georeferenced TIF file to rectify?

I have added a TIF file (size 1,433 KB) in ArcGIS 10.2.2 and defined numerous georeferencing points, with the aim of creating a raster file for conversion to polygons. However, on clicking the ...
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17 views

How to assign contour values directly from raster extracted tiff [on hold]

How to assign contour values automatically from contours extraced from classified rasters...thanks
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14 views

Error in merging two raster files (precipitation) in QGIS

The newly computed geotiff shows the extent of both raster layers, but only the data of one. If I use identify features tool it gives me only the values of the visible part not of the other part. I ...
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2answers
78 views

Accumulated value from many rasters python/arcgis10

I need to calculate an accumulated value of temperature (as an additional raster) from many rasters. Is there any option to do this in ArcGIS 10 or any hints for a python script?
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2answers
50 views

Raster image thresholding using python

I would appreciate if someone could guide me for applying thresholding technique to input raster image using Python. I intend to extract impervious surfaces from a high resolution raster such as ...
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0answers
14 views

Change detection between two Landsat scenes? [duplicate]

I want to do time series analysis and find change in NDVI. I have rasters where each pixel is represented by some value at a time. Also I have same thing but represented by points. And I would like ...
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0answers
14 views

Raster images overlaying each other but shouldn't

When I open a new map document and drag different raster images into the map the images stack on one another rather than form the complete image of a country. When I try zooming in, the multiple ...
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2answers
503 views

Confidence interval from raster data

I have raster data that represents a probability distribution, i.e. each cell has a probability value (in my case the probability that an animal may be found in the cell), and all the cells add up to ...
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1answer
150 views

Weird raster visualisation

Using the hillshade tool (Arcmap 10) on a 30m SRTM raster downloaded from NED the result is the one in the picture. Why are there those crossed lines all over the raster? How could I remove them? ...
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1answer
60 views

How to separate details by color from raster?

How to separate details by color from raster? Is it possible in ArcGIS or any other software? I have tried Spatial Analyst. I want to use RGB .tiff image which is scanned map. It consists of all the ...
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23 views

How to create ROI in Semi-Automatic Classification plugin QGIS

while trying to classify landsat images, I get the following problem: I click on the pixel I want to define a ROI, but the ROI polygon that the plugin creates appears in a different part of the image ...
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13 views

Maxent does not create the distribution map

I've been using Maxent to run a model, the program produces multiple output files except the html file, the map pictures and the distribution map or raster file (.asc). Does anyone know why this could ...
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1answer
23 views

Enabling: Raster and Topology

I'm new to GIS and tile servers. I've installed TinyOWS pretty successfully except for what looks like to be some dependency issues. I have installed PostGIS and also PostgreSQL. PostGIS is supposed ...
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2answers
422 views

Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
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10 views

Recentering a tiled raster table in PostGIS?

Does anyone know a nice and easy way to recenter a tiled raster table in PostGIS? By recentering I mean that I have a raster that is centered on the Pacific, but I need to recenter it on ...
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1answer
706 views

Why does CON statement give ERROR 010240: Could not save raster dataset to (value) with output format GRID?

I am receiving the following error when trying to run the following code: import arcpy from arcpy import env from arcpy.sa import * arcpy.CheckOutExtension = "Spatial" env.workspace = ...
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2answers
30 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...
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2answers
30 views

add multiple rasters, each located a branch too deep in separate folders - ArcGIS

I have a year of daily raster datasets (365) that I would like to use the Cell Statistics tool on; however, each raster is located in a separate folder so I cannot add all of them at once. ie: ...
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2answers
52 views

Problem when opening a raster layer

I am a news user with QGIS API C++. In order to feel good with it I try some little program to explore class. I have download the tutorial 4 of the QGIS and adapted it to the 2.8 version but when I ...
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2answers
96 views

GDAL clips raster at wrong position

I try to clip raster data with GDAL (in fact I am using QGis, which produces me a command line for GDAL) The raster has been transfored to EPSG:3857, which is also the projection of the shape file ...
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1answer
34 views

Interpolation extent

the following pics will hopefully explain my problem. After interpolation an clipping the grid I get the result you can see on the pic. Next to the boundaries there are a lot of gaps caused by the ...
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1answer
31 views

Displaying raster tiles from OSM data stored in a postgis server

I have been recently tasked with setting up a raster tile server that serves tiles from data pulled from a postgis store. I have managed to get a vector tile server up and running but I'm stuck on ...
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2answers
49 views

Is it possible to georeference raster stored in Postgis?

I'm looking to store a huge raster aerial image (400 Gb) into Postgis, but before storing it i like to know how i could georeference or rectify raster stored in postgis ? is there any Qgis plugins ...
2
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1answer
294 views

ArcGIS model builder: How to reclassify 16,000+ rasters and do weighted sums on these rasters per year?

I've been trying to build a model in model builder (ArcGIS 10.1) which can do the following task: I have a folder full of ca. 16,000 raster files (.asc) representing mean temperatures for each day ...
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1answer
73 views

R - How to “smooth” a raster map

I am trying to create a map from raster data. The file came from a crop model, with resolution of 0.5 degree. Even when I disaggregate it (i.e. increase spatial resolution), the map looks really ...
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32 views

NDVI from raster to vector isnt working

I have question...can I make from raster img. vector file via qgis? Because Ive tried it on NDVI image and Ive only got one file with atribut table full of #null. Image is from landsat7... ...
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27 views

Obtaining NDVI data from selected area

I need to analyse NDVI (-1/1) change between years (05-10y). But still only under selected shapefile. To analyse the extent of each NDVI category. Any tips? I have tried to make vector from the NDVI ...
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2answers
772 views

Clip_management to raster extent outputs larger raster than raster extent

Using Python and ArcMap 10.0 SP5, I'm trying to reproject and clip a large input raster to exactly the same grid as a smaller target raster (same extent, pixel sizes and projection). The problem is ...
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1answer
388 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
139 views

QGIS SAGA Raster Calculator [closed]

I am using SAGA --> Grid Calculus --> Raster Calculator on QGIS version 2.6. The formula I am using is: ifelse(gt(a,0), (a), b) where a is my layer with values in a greater extent than that of b. ...
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1answer
10 views

Extract maximum raster value within a set radius to a point

I have lines (rivers) that don't exactly match a raster grid (flow accumulation). If they were exact, I could just extract the raster values to points I put along those lines. However the raster ...
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553 views

Histogram Matching Python

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: ...
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1answer
137 views

Combine overlapping rasters in gdal_calc.py, taking the maximum value from each pixel?

I want to combine 3 overlapping rasters to create 1 raster. Each have the same dimensions, resolution and CRS. I want to populate the new raster with the maximum value from each of the layers. ...
2
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1answer
147 views

ERROR 999999: Error executing function - Failed to execute (CopyRaster)

ERROR 999999: Error executing function Unexpected operation No spatial reference exists This is a fragment from my log report: ERROR 999999: Error executing function. Database user ...
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1answer
812 views

Problem in importing raster data from PostGIS to Geoserver

I am using Opengeo Suite 3.0.2, PostGIS 2.0.3 and PostgreSQl 9.2. I am trying to import raster data from PostGIS to Geoserver but facing an error. I follow this tutorial link to import the raster ...
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1answer
24 views

How to input Shapefile point data into a raster and have the raster adjust to the new data?

I have a shapefile with elevation data at specific points. I also have a raster that has incorrect elevation values, but the transition between pixals is what I need. Is there a way to put the values ...
2
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2answers
251 views

Spectral profile (z-profile) viewer for ArcGIS

I have multilayer raster with 6 bands. Is there a way to select one specific pixel and to display the z profile (the values of each band) for this pixel as a chart or table? I am looking for a tool ...
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5answers
728 views

Dikes extraction from DEM

I do have DEM of 1x1 meter and original LiDAR point cloud in .las, that DEM is made of. I need to extract river dikes (highest points of the dikes) to vector feature (point, polyline). Any idea for ...
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Raster alignment terminology?

I identify two types of raster alignment (assuming SRS is the same), but I am unsure of the correct terminology for these (or whether there is even a 'standard')? First, there is 'pixel alignment'; ...
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289 views

How to extract most probable flow line from multiple lines?

I have to apply uncertainty principle to computing flow accumulation using Monte Carlo method. I generate raster with random numbers which represents mistakes in creating DEM. Then I apply those ...
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3answers
30 views

Creating a new raster layer based on mean of other raster layers, ignoring NA values in R

I am trying to create a new raster layer that is made up of the mean values from 7 other raster layers. I get results using overlay function mean: mean <- overlay(2000, 2001, 2002, 2003, 2004, ...
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2answers
5k views

How do you use GIS to detect percentage of Land Use Change

I am a student in GIS I have a dissertation about land use change. I have questions about using ArcMap 10 for this aim, how can using GIS to detect the percentage of land use change. For example we ...