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

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1answer
29 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 ...
0
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0answers
14 views

Plotting Raster in R give 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 ...
0
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1answer
26 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 ...
0
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1answer
21 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() ...
3
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1answer
613 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. ...
2
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1answer
37 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
0
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1answer
166 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
578 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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0answers
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?
1
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1answer
12 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, ...
0
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2answers
164 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
28 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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0answers
12 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 ...
1
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1answer
54 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 ...
0
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0answers
24 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 ...
1
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1answer
15 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
votes
1answer
24 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 ...
1
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1answer
25 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
59 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 ...
1
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2answers
276 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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0answers
31 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
25 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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0answers
50 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
271 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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0answers
19 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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0answers
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 ...
2
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0answers
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
34 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 ...
0
votes
1answer
493 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. ...
3
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2answers
42 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 ...
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1answer
31 views

Exporting a raster with renderer enabled to file

I have a problem when trying to export a layer with renderer to a file. Basically, what I have at start is a correct IRasterDataset. Then I define a stretch renderer in form of IMultiPortColorRamp and ...
3
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0answers
30 views

How to calculate average value of a raster, that is clipped by multiple polygons?

I am using QGIS 2.12.0. I have a raster of coherence value (SAR interferometry) and a land use shape. I wish to calculate mean coherence value for those areas with a specific land use. I split land ...
9
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5answers
10k views

How to calculate raster statistics for polygons?

how can I calculate sums, averages etc of raster-points (multi-band) per polygon of a vector-layer. I was told that this is called "zonal statistics". I tried that with QGIS first. There is a way to ...
2
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0answers
18 views

Grid buffer in QGIS

I do have a raster file (grid) which I have processed before with the SAGA kriging tool. Is it possible to buffer this raster file a little bit (expanding the interpolated result) of 1 or 2 grids? I ...
6
votes
1answer
125 views

Free open satellite or other remote sensing data for night time?

I usually work with daytime satellite images to do some image classification (mostly Landsat data from the USGS EarthExplorer). Right now I'd like to check at some night time images to work on city ...
2
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1answer
28 views

problem when doing algebra with raster layers in R

I'm trying to combine bioclim raster layers to create the following layer. (Q) = AnnPrec/[(Tmax+Tmin)*(Tmax-Tmin)]*1000 For that, I import a bioclim stack: envirc = ...
2
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0answers
16 views

Adding a custom color scale for a sp.points layer to levelplot() legend

I'm wondering how I can add a customized color palette that I used to display a sp.points layer in a call to levelplot (lattice plotting) in the rasterVis package in R. I used a function that Dave X ...
1
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0answers
37 views

Spplot SpatialPolygonDataFrame and SpatialGridDataFrame

I have to plot in the same graph something like this: Then, I have elements from SpatialPolygonDataFrame class and others elements from SpatialGridDataFrame class. When I try to plot them in the ...
0
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0answers
20 views

Error 010422 when combining rasters

I have 17 rasters, some of which overlap one another. I wish to combine them such that where the rasters overlap the sum of their values is taken. I have tried combining them using raster calculator, ...
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vote
0answers
34 views

How do I change my “no data” values to get “true” values in raster calculator in Qgis

I have two rasters and I want to subtract the values from one of the layers. The first raster is a altitude raster and the second raster is depth values for a lake. I would like to subtract the depth ...
0
votes
2answers
432 views

problem to open a netCDF and create a raster file

I want to open a netCDF file and create a raster with ArcMap 10.2. The file contains the mean monthly temperature for Switzerland. I found it in meteoswiss web site. I tried to open it with the ...
3
votes
1answer
28 views

QGIS Raster Calculator syntax

I have tried this several different ways and get lots of NaN. I need to specify that in my raster 'test1', I want a certain set of values to equal 1 and the rest to equal zero. For instance, I want ...
2
votes
1answer
67 views

Raster statistics for polygon areas PostGIS

I'm trying to get zonal raster statistics for each polygon area. I have used the following method from this site: SELECT bufid, (ST_SummaryStatsAgg(ST_Clip(rast, geom, true))).* FROM rasttable, ...
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1answer
222 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 ...
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2answers
1k 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 ...
0
votes
1answer
30 views

How to extract all pixel values in a raster file

I have a image difference from ArcGIS, which i have performed a remap function on. The layer is a temporary layer and does not have an attribute table, i need all the pixel values to do a frequency ...
9
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2answers
870 views

Scriptable alternative to ArcScan (particularly vectorising lines within tolerances)?

Sadly the answer to Can you access ArcScan from a python script? suggests that it is not possible to script ArcScan from within a python script. Therefore, does anyone know of any alternatives to ...
4
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2answers
528 views

Digitizing raster in ArcGIS Desktop?

I have the raster below which I want to convert to a set of vector lines: As you can see, there are small breaks in the lines and some bits are double-width. I want to be able to reliably import ...