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

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ASCII to Raster Problem

I have some ASCII code of NDVI values and I want to create a raster from these ASCII values, but there is an error during execution: ASCII file data is available on this URL
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14 views

Which is better for measuring actual ground elevation, NED or SRTM?

I know that NED DEM layers are created using mainly Lidar point clouds and that the SRTM derives its data from shuttle-based radar. I have both of these loaded into QGIS and can see that over my study ...
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2answers
38 views

Rasterizing polygons with the function “gdal_rasterize” in R

I'm using the function gdal_rasterize in R (package gdalUtils) to convert a polygon shapefile into a raster. Here is my code: r.test <- gdal_rasterize(src_datasource="df.shp", ...
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13 views

Change raster projection in R

I'm trying to change raster projection using R and its raster library. The input raster projection is Lambert Azimuthal; this one and other params can be seen here: ...
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1answer
33 views

R: count raster values using another raster as mask

I would like to count the frequency of values in one raster, using another raster (different resolution) as the zonal condition. The premise is that the coarser resolution raster represents the area ...
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16 views

Calculating water flooding with raster calculator [Solved]

I have many layers so i will try and explain what all the layers are. What I want do is enter a calculation in raster calculator to calculate what areas of the map will be flooded if the water levels ...
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2answers
29 views

Changing point data coordinate system without moving points in QGIS?

I made a mistake regarding coordinate systems and lining up two layers. I have a raster with elevations in EPSG:2949. I created a point data shapefile and entered about 600 hundred points manually ...
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4answers
910 views

Assigning RGB values from Geotiff image to LiDAR data, using R

I have given a Geotiff image and its corresponding Lidar data (x,y,z) in UTM coordinates. I need to merge the Lidar data with the RGB values from the image. That means, at the end, I need to plot ...
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1answer
23 views

Extracting the cell size of a Raster as a value to use in buffering

I am creating a model in ArcGIS modelbuilder to buffer a line. I would like the buffer distance to be based on the cell size of a raster. The cell size may change depending upon which raster the user ...
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0answers
14 views

How to get a multi-attributes vector from an SRTM raster in QGIS?

I split an SRTM raster into 3 different raster files representing the altitude, the slope and the exposure, using QGIS DEM analysis tools. How can I output a single vector file with the 3 attributes ...
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4answers
3k views

Clip raster using shapefile into multiple rasters using ArcGIS Desktop?

I have a raster file representing a large area and a shapefile of 30 polygons representing watersheds. I would like to clip the raster with the shapefile to create 30 rasters representing each ...
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24 views

Zonal statistics shifted

I am working with QGIS (newbie). I have a raster map with 0.5degrees resolution. I created a 0.5degrees width grid layer and I compute zonal statistics from the raster. My problem is that it seems to ...
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16 views

Raster images in geoserver without WMS

Is there any vailable way to access raster images through geoserver without wms?(to a large number of images)
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2answers
25 views

ArcGIS Multiband Raster

I know this has been asked and answered here but since I don't have enough rep to ask a clarifying question to the person who answered it I am having to post a completely different question. I am ...
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1answer
16 views

Inverse Distance Weighted (IDW) Interpolation with Radial Basis Function (RBF) in R

I want to perform an IDW interpolation with R. I am aware that I can do that with gstat::idw. But I want to change the parameter 'idp' with a radial basis function (RBF): where is the ...
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1answer
915 views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster ...
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2answers
31 views

aggregate raster using the most frequent value

Does anyone have an idea how I could aggregate my raster so that in the output the most frequent value is used, as shown on the picture?
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1answer
259 views

GDAL and Python: How to “pad the extent” or otherwise handle band.ReadRaster() for area falling slightly outside the image bounds?

In a nutshell, I'm trying to create a bare-metal tiling utility using GDAL and Python. As you can see in the graphic below, which shows the perimeter of a raster and the OSM-structured tile index, ...
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30 views

Plotting Raster in R gives error

I know this is not much to go off of, but I can't seem to find the answer anywhere. I was plotting this raster image on Friday and it worked, and now when I try to plot it, I get this error. The image ...
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1answer
50 views

Building predictive maps of response variables in R

I am a novice in spatial statistics in R. So, I am looking for some advises. In particular, I would like to create a predictive map of capture success from a generalized linear mixed-effects model ...
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1answer
30 views

Contour extraction from raster does not finish in Qgis. How to find out if a raster is damaged

Execution of "extraction" - "contours" in Qgis is impossible. The process never finishes, I stopped it after 35 min. The contour extraction works for all other raster files. I have tried with ...
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1answer
22 views

Tearing of SpatialLinesDataFrame and problem with gClip function

I am trying to use ggmap with geom_map and geom_path commands to add a SpatialPolygonsDataFrame of African countries and a SpatialLinesDataFrame over a raster. When I use the defined function gClip() ...
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1answer
616 views

Georeferencing multiple rasters to World files in ArcGIS for Desktop?

I've got exactly 56 tiffs to georeference. Each raster has its unique TFW world file. I'd like to automate this process. Each raster has it's unique name which is consistent with world file name (eg. ...
3
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1answer
38 views

How to derive a hydrologically correct DEM from point shapefile using QGIS?

I used grass gis v.surf.rst function to interpolate a surface using vector points. But it is very difficult to find a optimum parameters to be used. I am still unable to develop a accurate terrain
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1answer
167 views

using raster.predict for Cubist model, factor levels list

I would like to thank in advance any help or advice. Let me know if I need to provide more reproducible data/code. I am working on a Cubist prediction model for soil texture, using continuous and ...
3
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1answer
579 views

How to get the Flow or directional raster map using GRASS?

Aside from using r.fill.dir in GRASS, is this the script to produce the Flow or directional raster map? Is the output for the script the following graphic? ...
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15 views

Combine latitude, longitude and value ascii files

I have three ascii files of latitude, longitude and value. How to combine these three ascii files into a single raster of GTiff format?
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1answer
15 views

PostGIS update data with ST_Tile

I need to update tiled raster data from the "whole image". I have created this query: UPDATE data_tiled AS t SET raw_data = f.raw_data FROM ( SELECT data_time, data_type, ST_Tile(raw_data, 250, ...
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2answers
166 views

Extracting multiple values of raster to polygons using ArcGIS for Desktop?

I was hoping I could get some help on how to extract information from a land use raster using polygons. I have a layer with 157 polygons and a land use raster with multiple land use categories for the ...
3
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1answer
36 views

Getting different pixel depths from output raster when done in ArcMap versus Arcpy?

When I use 'Plus' in Spatial Analyst to add together two 8-bit unsigned rasters (pixel values 0-100) the output raster is 8-bit unsigned (pixel values 0-200) but when I try and do the same thing ...
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13 views

raster doesn't redraw to fit the canvas after a zoom in and a pan

i am working with qgis 2.8.2, c++ api and qt 4.8.5 i have a layer in the mapcanvas, this layer contains a raster ( a georef tif picture ) when i zoom in, the raster fill the entire canvas , ok but if ...
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1answer
58 views

How to find the height information from LiDAR point cloud data [duplicate]

I need to find the biophysical parameters(biomass) from the LiDAR point cloud data. For that I need the height of the trees from the data. Currently I am having the general height with respect to sea ...
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25 views

First time rasterio error

First of all, I am new to python and rasterio. I am trying to open a simple raster with 5 bands using the rasterio module in python. This is what I am trying to achieve: import rasterio with ...
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1answer
22 views

How to merge raster with FME with different spatial resulution?

I have two sets of raster (tiff, aerial photos) which I want to merge to one raster file with FME. The two sets have different spatial resolutions. Set A has a better resolution as B. The two set do ...
3
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1answer
26 views

Combining rasters using weighted average

I am using ArcGIS 10.3 with spatial analyst. I have a series of several rasters that I am trying to combine into a single raster layer. The rasters are all different sizes (different extents) and were ...
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1answer
26 views

Pattern fill for raster contours in QGIS

How do I fill the area within raster contours with a pattern fill, instead of colors in QGIS? Is this even possible?
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2answers
61 views

PostGIS convert point->raster->GeoJSON

My question is a follow up to Convert a raster to GeoJSON polygons in PostGIS I'm trying to accomplish querying point data from the database, and then turn that into a raster for calculating ...
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2answers
282 views

How to set the cell size of a tiff to 1 meter when working in a Geographic Coordinate System?

I am working in a Geographic coordinate system in ArcGIS, and I need to create TIFFs by exporting rasters. THese .TIF file must have a resolution (cell size, or GSD) of 1 m. Is it possible to set any ...
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33 views

Geoserver ImageMosaicJDBC problem with interpolation setting

I use the ImageMosaicJDBC plugin to connect to an Oracle raster table. Maybe someone can clarify some things about the interpolation settings. There are multiple location where I can define the ...
2
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1answer
28 views

QGIS: Only view raster data within polygon

So i have this raster dataset in .ASC-format. I defined a bounding box polygon of my study area: Now i want QGIS to only show the raster data within this boundary box without changing/adapting the ...
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51 views

R raster() function failed to read tif file

I wrote a few lines to load data in TIFF to R. The function I used was: library(raster) test <- raster("file name.tif",package="raster") and it worked perfectly last week. However, now I am ...
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1answer
276 views

How to calculate zonal statistics from multi-band raster for each polygon using python?

I want to calculate the zonal statastics from multi band raster for a polygon layer. When I am using this snippet of code: vectorlayer=qgis.utils.iface.mapCanvas().layer(0) rasterfile = ...
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21 views

I would like develop an Android GIS app which should support offline navigation [closed]

I would like develop an Android GIS app which should support offline navigation, that means it should allow to downnload offline maps such as toposheets which were convertred into .KMZ format. Android ...
3
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1answer
34 views

Spatial join of raster data in QGIS

How do I perform spatial join of raster data in QGIS? I have raster soil data (tiff), I'd like to join this to an attribute table in excel? I'm not able to view the attribute table either? Is this ...
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27 views

create a grid and extract species and climate data [closed]

I am looking for R support to arrange my dataset which I tried and failed in Arc GIS. If you have an idea please let me know. I have 6 bioclimatic variables and 14 species. I want to create a ...
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50 views

Why azimuth result is wrong for this pyqgis code?

In this code I want to obtain azimuth from a single point to each pixel center, but when run it, in raster created azimuth result for each pixel is wrong, what is correct code? from osgeo import ...
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1answer
38 views

Spearman correlation between two rasters in R

I have two rasters of the same area. The only difference is that they were created using two different methods. I would like to compare them and see how correlated they are pixel by pixel. Any ideas ...
4
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1answer
55 views

Why does an 32-bit FGDB raster have a smaller file size than 8-bit?

Using Arc 10.0, I have a single band, 32-bit signed raster as the only item in a file geodatabase. Using ArcCatalog, I copy that raster to a new geodatabase with an 8-bit unsigned pixel type. As ...
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1answer
503 views

How to fill holes/missing values in XYZ data / a DEM with QGIS?

I have equidistant XYZ point (text) data that I used to create a point grid. However, it's not perfect - there are some holes. I then created a DSM raster from it, which obviously has the holes too. ...
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2answers
43 views

Align raster to fishnet using ArcGIS 10.3

I am having some trouble aligning a raster (elevation) to a fishnet I created. The cell sizes for both the raster and the fishnet are 30x30 meters. I have tried using the clip and extract by mask ...