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

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Map netncf-file with different years and save the different layers in shapefiles

Download from this website the following netncf-file: cru_ts3.23.1991.2000.pet.dat.nc.gz. This is a monthly raster with data from all over the world from january 1991 to december 2000 I am using ...
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2answers
44 views

Add information from a raster nc-file to a polygon shapefile

DATA Download from this website the following ZIP file: NUTS_2006_60M_SH.zip and save all the NUTS_RG_60M_2006 files. In what follows I refer to this as "NUTS3 regions". Download from this website ...
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0answers
28 views

Open raster and vector files with PyQGIS

I'm making a plugin for QGIS and I'm trying to open the layers I've created on QGIS, but I only get to open the one called 'sinkhole raster' which is the input of the tool. I don't know what order ...
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1answer
33 views

Removing Polygons With a Specific Size

How can I remove small polygons from a raster data set? I know that they aren't technically polygons, but I convert the rasters to polygons. The problem is that I want to focus on a specific polygon ...
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24 views

How to import TIF image with extents known but world file missing

I am having some real trouble figuring out how to import a tif file for which I know the corner coordinates but do not have the TFW (world file). I have tried changing them in properties but that ...
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1answer
25 views

SAGA Raster Calculator in QGIS Graphical Modeller not subtracting [closed]

I am using QGIS 2.8.1 to build a model. All is working fine until the raster calculator input. I understand that the raster calculator in QGIS Modeller is a SAGA tool. With this, I have tried both the ...
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1answer
439 views

Can I update the service on ArcGIS for Server programmatically?

There is Windows Service. This service adds user raster data to the Raster Dataset in sde database. The Raster Dataset registred on the ArcGis Server. This Raster Dataset also was publishing on ...
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1answer
38 views

Calculate Raster with value from table

I would like to multiply all the values within a raster layer with one value, which is written in an *.csv table (it is the only value in this table). I tried this code (changing Times tool to Minus ...
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2answers
297 views

How to extract raster pixel value in ArcGIS

I am dealing with some very large geotiff files (the whole of Canada at a 250m resolution) and is having trouble to extract the pixels value as I need to do some calculations for mapping ecosystem ...
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28 views

Is Output Cell Size Environment the same as Resample tool?

I have a raster catalog that contains hundreds of rasters (10 x 10). I need to perform Cell Statistics SUM on all the raster. End user able to specify under what cell size the want to perform the ...
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1answer
40 views

Array written by GDAL with Python script has numbers read as “nan” by QGIS?

I would like to write an array to a geotiff with Python script using the GDAL module. When I try to do something simple like copying an existing GeoTiff via reading it to an array, then, writing to a ...
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1answer
1k 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
39 views

relating land cover raster to vector data

I have a land cover raster basemap that covers different land cover/uses in Europe to 100m resolution and a separate Excel legend file. Separately I have a point shapefile with the details and ...
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5answers
4k views

Reproduce raster with same extent, and same number of columns and rows?

I have two raster A and B. A and B have the same grid size but different extent. How can I make A have the same number of columns and rows, as well as the spatial extent of B?
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4answers
3k views

Increasing speed of crop, mask, & extract raster by many polygons in R?

I'm extracting the area and percent cover of different land use types from a raster based on several thousand polygon boundaries. I've found that the extract function works much faster if I iterate ...
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2answers
452 views

Really slow extraction from raster even after using crop?

I have a large raster file (245295396) cells and stacks of rasters having 4 layers each which lie in the extent of this large raster. To start with I am trying to get value from one stack (3 channels) ...
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1answer
42 views

QGIS “Raster->Georeference” menu item not showing up

I am using QGIS 2.12.0 Lyon. I have installed a plug-in called "Georeferencer GDAL" and the version of that plug-in is 3.1.9 . [I am working on a Mac which is running OS X Yosemite 10.10.5.] I am ...
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2answers
17k views

How can I convert data in the form of lat, lon, value into a raster file using R?

I have a data set of values over a km grid in the continental U.S. The columns are "latitude", "longitude", and "observation", e.g.: "lat" "lon" "yield" 25.567 -120.347 3.6 25.832 -120....
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0answers
15 views

PostGIS - raster - bit operations

I have a raster data in the database in separate rows. I would like to select 2 rows and do a bit operation with them (like |, &) and store the result in memory as a query output. Is this possible?...
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1answer
193 views

QGis export part of map (box with coordinates) as raster

I would like to export a map of Switzerland (as part of googlemaps) to use as a background for a graph, but I need to know exactly where each corner of the map corresponds to (wrt spatial coordinates)....
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1answer
285 views

How to download the MODIS data from R using MODISTools library

I want to download MODIS product MOD13Q1 to use the Scientific Data Sets (SDS) layers of "250m_16_days_EVI", "250m_16_days_pixel_reliability". MODISTools library in R software provides the capability ...
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0answers
15 views

ArcGIS trim-mean interpolation

I am trying to create a raster dataset from regularly spaced point data. I would like to use a trim-mean function rather the more standard mean function. Is it possible to do this?
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1answer
20 views

ASCII Raster Statistics?

I have downloaded the following precipitation data in .nc4 format(attached). I have opened the 'PRECIPITATION' variable in the file in QGIS and I have made a note of its statistics. As working with nc ...
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1answer
1k views

Converting DEM to Floating Point Raster (FLT) using QGIS?

I am looking to convert a .DEM exported from AutoCad to a floating point raster file type (.FLT) utilizing QGIS to implement in HEC-RAS Mapper. This is accomplished easily in Arc using the Raster>...
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1answer
41 views

How to represent seasonal variability in a single global NDVI map?

I have twelve monthly MODIS datasets for a 1 year period (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD13A2_M_NDVI&year=2015) and wish to combine all the data into a single map highlighting ...
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2answers
25 views

Geoserver WMS raster problem

I have the following problem: The edge of the imagemosaic is not fit well, Im using geoserver imagemosaic tool to serving orthophotos through wms server. Is it a CRS, Bounding Box problem?
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52 views

Working out percentage of different raster parcels in polygon?

I have a raster layer (LCM2007) that contains 24 classes of landcover and a shapefile, polygon, which represents areas in a survey. I want the area, or percentage, of each class in each area. For ...
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32 views

Failed to create raster dataset using ArcObjects?

I am currently unable to create a raster dataset. These are the 2 functions i have for creating the raster dataset but it seems to always throws an error "unable to create raster dataset". After ...
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2answers
64 views

Copy resolution extent CRS metadata from one raster file to another using raster R

I have two geotiff raster files, one has all the metadata information and in the other the information was lost. I know that all the metadata information was exactly the same so I want to copy it from ...
4
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1answer
718 views

How do I combine bands in a tiff then convert to grayscale?

I have a large mosaic of tiffs in which I need to do the following: -Combine bands 4,3,2, for an infrared image then convert the image to grayscale without producing another dataset -This is easy on ...
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2answers
546 views

How to get easting & northing of cell in raster using ArcPy?

It might be very simple task. But I would appreciate if someone can comment on How I can get easting and northing of a single cell raster using arcpy as this value is used for in further steps.
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1answer
33 views

Raster time series smoothing package using R

Does somebody knows if exist a package in R specifically for raster time series smoothing? I´m using aproachs like this one (using the equation suggested by Hamunyella et al., 2013) for (i in 2:(...
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1answer
81 views

QGIS set default style for layers based on name

I know that it is possible to apply default fill/line/point and colour ramp styles for layers within a project, However... I have a model which spits out raster layers with defined names (e.g. ...
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27 views

Pixel based 10 year NDVI time series

I would to do pixel based 10 year NDVI time series analysis using MODIS data. I’ve 3 seasons in a year. Should I average all values in the study area per season?
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38 views

Improving Clip Raster workflow in QGIS?

I've tried to come up with an open-source equivalent to the following process in ArcGIS 10.3: Spatial Analyst Toolbox > Extract by Mask target input: 1" SRTM DEM in EPSG 4019 mask layer: single ...
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0answers
48 views

Resample raster to lower resolution

I am trying to resample a forest cover raster with high resolution (25 meters) and categorical data (1 to 13) to a new RasterLayer with a lower resolution (~ 1 km). My idea is to combine the forest ...
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0answers
21 views

Interpreting output from PCA tool of ArcGIS for Desktop?

I am looking for some assistance on interpreting the output from a PCA run in Arcmap. My data is comprised of 6 raster bands representing biophysical elements in the marine environment (SST, ...
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2answers
56 views

Can I extract circular buffers from polygon layers?

I have been working in QGIS with a large and detailed shapefile where remaining forest fragments are represented as polygons. I would like to extract circlular buffers, of various radii, from this ...
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1answer
53 views

Python Gdal write virtual raster

Is there a python module to create Virtual Raster (.vrt) xml files? Rather than writing text strings to a file, I'd like to know if there is an automated way to do this.
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0answers
8 views

How to do not display Nodata values on IMG raster

I have a problem when I try to visualise (in ArcGIS 10.1) a raster file on IMG (ERDAS IMAGINE) format. The NoData values are displayed in black and I cannot find a way to do not display them. I've ...
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1answer
35 views

How to doing spatial join for several rasters

I have four rasters, each of 32 bits (single band), with the same cell size, the same number of rows and columns and identical extension. I need to make something like a "Spatial join", I mean, I need ...
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0answers
51 views

Extracting Mean from Raster and Writing to Table in ArcPy?

I am simply trying to extract the mean of each raster within a geodatabase and write the value to a table. I have done this successfully with another set of rasters, but now I keep getting the ...
4
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1answer
68 views

How to selectively generate averaged raster layer from 5-year data raster layers in QGIS?

I would like to merge 5 years of world ocean surface productivity data raster into 1 averaged raster in QGIS. However, not every pixel has data in every year. To generate the raster layer with the ...
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0answers
29 views

Merging DEM file generted many negative value in QGIS

With four DEM files downloaded by Python Elevation package, I merged them in QGIS 2.8.3. I use raster-> Miscellanaous -> Input direction, no more attribute was added. The four dem data has ...
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0answers
50 views

How to calculate raster area or number of cells for multiple classes in a raster?

I have a raster with many classes and I want to know the area or the number of cells for each class. I found quite a few posts on this topic (see links below). None of the suggestions matched my ...
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3answers
2k views

Calculating area of vegetation in raster file?

How do I calculate area of several vegetation types in a raster (.img file type) image. They are color coded. Am using QGIS (1.8.0) and ERDAS 9.2.
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3answers
53 views

Calculating raster area?

I would like to know how to calculate area of raster image based on cell? based on night light data I classified the image and i need to know the area of that particular classified area
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2answers
2k views

Calculating area of rasters in QGIS?

I have been working with some rasters and would like to know how to calculate the area occupied by one element of a raster in QGIS?
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3answers
122 views

How to extract values from raster at points with many different rasters and points

I have a folder containing 100 DEM rasters. I have a point file containing thousands of points. I need to collect raster values at all of these points. Only some of the rasters intersect with the ...
7
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6answers
4k views

Continuous color band for a raster legend in QGIS composer legend

I'm looking for a way to insert continuous colour legend for a raster layer. I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values ...