GRASS GIS (Geographic Resources Analysis Support System) is a free, open source geographical information system (GIS) capable of handling raster, topological vector, image processing, and graphic data.

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2answers
40 views

GRASS GIS not starting

Hello my name is Luca and I write from Italy. I have a problem with GRASS GIS 6.4.3. Last week I installed QGIS 2.4 with GRASS GIS 6.4.3 GUI on Windows 7 64 bit - admin user. When I click on GRASS ...
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0answers
31 views

QGIS OD matrix assignment on network

Using QGIS, I would realize an assignment of an OD matrix on a network, like this one on Transcad. I have: - network - points of Origin and Destiny - flows of traffic for each OD I found a solution ...
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0answers
7 views

GRASS GIS and Liss4MX

i am working on grass gis. how to use grass gis for liss4 of IRS-P6.I have to do atmospheric correction for hilly terrain data.i would like to use grass's i.atcorr. may i know the dependencies and how ...
1
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2answers
29 views

How can I import tif file in GRASS GIS

While importing TIFF image to GRASS GIS, I get an error: Location PROJ_INFO is: name: Lambert Conformal Conic proj: lcc datum: nad83 a: 6378137.0 es: 0.006694380022900787 lat_1: 36.16666666666666 ...
0
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0answers
11 views

How can I implement GRASS GIS flow direction process from DOS scripting

When I try to implement its showing it work completely in its command prompt(grass) and creating output files also but when I try to view the result its not showing anything in Map Display I ...
1
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0answers
33 views

using r.volume model GRASS plugin in QGIS

I am calculating volume of bathymetric data in the form of a clipped raster in GRASS with a Custom Lambert projection centered around 70degrees North, using the module r.volume in GRASS. Side note: ...
0
votes
1answer
22 views

v.generalize on massive vector data

I have a contour line file that covers the most part of north italy (shape is 0,6 gb) and I want to use v.generalize (snakes algorithm) on it. Because of the large file size, if I use Grass 6.4.3 I ...
2
votes
1answer
44 views

How to properly open an ASTER data?

Yesterday i downloaded an Aster L1B image from USGS's website. If i load it in QGIS, it doesn't get displayed properly(location wise). Even after i've enabled "On the fly" option, it's not reading the ...
2
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0answers
36 views

How to merge overlapping and duplicate lines from vector layer to one single line?

I used the "polygone to line" tool from QGis, to get a line-layer from this polygon-layer: unfortunatly this causes overlapping and duplicate lines, after I broke the qgis-export via GRASS into ...
0
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1answer
19 views

trying to calculate volume using r.volume GRASS - error message

I am trying to calculate volume using GRASS plugin in Qgis using module r.volume however the attached error message keeps appearing. Any ideas?
2
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1answer
30 views

How to convert tif to dep extension?

In white box when i try to import or do any processes it's asking .dep extension How can i convert .tif into .dep extension?? If try to pass LISS3 data in GRASS GIS it is taking as single bands. So i ...
6
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3answers
127 views
+50

Cutting out depth information in raster. Calculating volume in Qgis

I am trying to calculate habitat volume for around 30 fish stocks in Qgis. I have habitat areas (shape files) and Bathymetric information (.tif file). I believe I can calculate the entire volume of ...
1
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1answer
32 views

Error importing raster into GRASS plugin in QGIS

I am trying to import a tiff raster file into GRASS however every time I do this the below error message comes up. I am using a custom CRS so I have tried changing it back to the default CRS but still ...
1
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1answer
31 views

Setting resolution for GRASS raster

I am trying to calculate volume using the GRASSplugin. I have my area information in vector format and my depth information in raster. I read that it is important to set the raster resolution before ...
3
votes
1answer
50 views

ArcGIS Desktop equivalent to GRASS r.geomorphon algorithm?

I would like to know if in ArcGIS Desktop 10 there is some tool/algorithm which can be used to perform the same analysis that r.geomorphon does in GRASS 7.
1
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0answers
23 views

Create “grid” of polygons with the same 3D area based on an underlying raster variable (e.g. DTM height)

This could apply to point or raster values but imagine a raster of a continuous variable such as height (DTM). Is there a way to create a complete coverage of polygons that will have an equal area, ...
1
vote
1answer
34 views

How to interact with GRASS GIS vector map topology “level/layers” from terminal/command line?

Is there anybody out there that can maybe assist in the most simplest form of code to call on command line to "export topology" (which is level 2 information in GRASS) as separate spatial data, as ...
3
votes
3answers
125 views

Can a shapefile, or other file, be made from Excel without coordinates

I have two Excel spreadsheets I'd like to make into shapefiles, or some equivalent. I have access to ArcGIS at work and want to try using GRASS as well. I have seen the help on doing so, but only if I ...
1
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1answer
34 views

My RapidEye image won't appear in GRASS GIS

I have several RapidEye images that I want to use for object segmentation in GRASS GIS. When I import the the bands they all look like this and the same goes with a RGB composite: I've used these ...
4
votes
3answers
68 views

Create a rectangular buffer from point shapefile using QGIS/GRASS/SAGA GIS/R

I have a points shapefile and I want to create a rectangular buffer (22 x 16 km) around each point. My goal is to create a 16x22 km grid where each of the points is the centroid of the grid. Seed the ...
2
votes
2answers
75 views

How to create isochrones from streets with distance values?

I have made isochrone lines using GRASS and QGIS, as shown. The lines show various distances to fire stations on a street network. Now I would like to turn these lines into polygons that look like ...
3
votes
1answer
40 views

Merge different Landsat scenes in Grass GIS

I am new to Grass GIS, and I really need some help in solving this issue. I have 17 scenes from Landsat8 covering an area. I have created color infrared images of bands 5,4,3 and now I want to merge ...
-3
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1answer
108 views

How to extract drainage line network from GRASS GIS and QGIS [closed]

Giving DEM as input is there any way to get drainage network? I am newbie to GRASS and QGIS ,provide any working examples in GRASS GIS and QGIS with procedure.
1
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1answer
19 views

DEM error when trying to do topographic correction in GRASS

I'm new to GRASS gis and I'm trying to do a topographic correction (i.topo.corr) of 9 ASTER bands using SRTM dem. I keep getting this error message: ERROR: Illumination model is of CELL type Is ...
3
votes
1answer
58 views

Underwater terrain modeling

My task is to model the surface of a lake bed, calculate volume of it and visualize it as 3D a surface. I have acquired depth measurements in a small lake using echosounder. The precision should be ...
2
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0answers
40 views

best method for gridding or interpolating elevation data

I wonder if someone can recommend the best method for gridding elevation data in QGIS, GRASS or similar. The elevation data I have is collected along 1m spaced lines at approximately 1 reading per ...
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1answer
23 views

3D rubber sheeting using ground control points

I have 3d lines that I would like to rubber sheet or rectify in 3D (including z rectification). I used ogr2ogr with -gcp, however all the vertex of a polyline were set to a single elevation, and since ...
1
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1answer
39 views

Import shapefile into GRASS in QGIS

I am using the GRASS interface in QGIS 2.4. I have successfully imported my shapefiles into GRASS using v.in.ogr, but when I try to then use a GRASS tool, like v.net Network maintenance, the select ...
1
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1answer
27 views

Create Addons for GRASS GIS

Is there a complete guide - example describing how to create an add-on/plugin for the GRASS GIS? I would like to extend the GUI with extra menus and toolbars creating extra functionality.
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0answers
17 views

Cost Surface No sense Results. GRASS

I have some doubts with the generation of a cost surface with r.walk of GRASS. It's assumed that the resulting layer is measured in seconds, but when I try to convert seconds in days march (6h per ...
0
votes
1answer
22 views

How to batch export using r.out.gdal command in GRASS

I created a list of files (NPPFILES) using g.mlist command in GRASS 7. Now I would like to export these files as .tiff files. I tried this command in GRASS prompt for files in $NPPFILES; do ...
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0answers
20 views

PostGIS commands in GRASS

How does the geometry get referenced in GRASS when using a PostGIS command like st_within? e.g: echo "UPDATE file SET within=(select file2.name from file, file2 where st_within(file.geom,file2.geom) ...
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1answer
40 views

r.sun delievering unrealistic Values

I need your help. I'm trying to calculate the global irridiation for a specific area. I'm interested in the results for rooftops in special. I have a DEM, calculated slope, aspect and horizons and ...
1
vote
1answer
23 views

Preserve polygon boundaries when vectorizing a raster according to a polygon vector

I have a raster which I clip by some polygons and then convert to polygon. I would like to obtain the same number of polygons in both my vector files. The problem is that some areas in the vector ...
0
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0answers
29 views

How to reference a number variable in r.mapcalc within QGIS graphical modeler

I need to run the following formula in r.mapcalc: (xor(abs(A-B),abs(A-C))>120)*A I would like to however use a user defined number input variable instead of the 120. I already have this variable ...
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0answers
64 views

How to create least-cost path between two polygons with GRASS?

I am completely a beginner in GRASS but I would like to use it to have the cumulative cost of moving between two polygons. More exactly, I would like to get the smallest cost from any point situated ...
0
votes
1answer
36 views

removing spurious lines in raster before or after vector conversion?

I'm looking for a feature/function in either python opencv/ndimage/gdal/etc. or qgis/saga/grass that will help clean up a skeletonized image that I'd like to vectorize into a shapefile of ...
2
votes
0answers
68 views

Pan sharpen Landsat 8 using Grass 7

I have followed this great tutorial on pan sharpening using Grass GIS 7 (I'm using beta 3). Everything in the tutorial seemed to have worked, but my final output is not as expected (pictured below). ...
1
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0answers
19 views

Free And Open Source Software Tools to orthorectify Pleiades imagery [duplicate]

Are there Free And Open Source Software Tools to orthorectify Pleiades, Worldview And Quickbird imagery as we do with COST tools such as ERDAS Imagine, PCI, ENVI, etc.?
2
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0answers
57 views

3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS

How can I make 3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS? I am quite new with GRASS. I have only managed to get a 3D view of the terrain so far.
1
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0answers
57 views

QGIS Grass Processing toolbox

I'm trying to use some of the GRASS tools from the processing toolbox in QGIS. I get the following Python error: An error has occured while executing Python code: Traceback (most recent call last): ...
3
votes
0answers
32 views

Option for 360 degree movie embedded in Open Source GIS software?

Is there any Open Source GIS software available to embed 360 degree movies with the map? For a COTS example, there is the Active Link Vision (ALV) extension for ArcGIS from IWANE.
2
votes
0answers
28 views

QGIS doesn't recognize GRASS commands

When I try to use GRASS commands in QGIS, I get the following error message: Missing dependency.This algorithm cannot be run :-( This algorithm requires GRASS to be run. Unfortunately, it seems ...
2
votes
0answers
24 views

Can't run SAGA or GRASS commands from QGIS processing toolbox [duplicate]

I can't run anything from this toolbox. I tried running SAGA dissolve polygons and got the following error : Oooops! The following output layers could not be open Dissolved Polygons: ...
2
votes
0answers
78 views

Problem loading output layer QGIS

Every time I run operations with temporary file output from the graphical modeler, I get the following error message: Oooops! The following output layers could not be open CLIP: ...
3
votes
1answer
38 views

Why GRASS 7.0.0 can't create a table while importing shapefiles from QGIS?

I use GRASS7.0.0Beta1 and QGIS 2.4.0 on Windows8. With v.in.ogr, when I import a shapefile, I get the error message "Unable to create table". When I put the option of not importing the table, the ...
1
vote
1answer
35 views

R.Mapcalc giving only blank maps as result

No matter what function I put in the r.mapcalc in the GRASS GUI I get a blank map full of null values. I even tried DEM+0 (I can see my DEM) and this also yielded a blank map.
3
votes
0answers
50 views

IS it possible to run GRASS commands in the QGIS graphical modeler?

I have a geoalgorithm set up in the graphical modeler and everything runs except for the GRASS commands. It is really frustrating because when I execute these commands on their own they work just fine ...
1
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0answers
19 views

R.Neighbors with large neighborhoods?

I'm running into problems running the r.neighbors GRASS command in QGIS. Although it will run for small neighborhoods as soon as I increase my neighborhood above a certain number it becomes unbearably ...
1
vote
1answer
141 views

QGIS GRASS Missing Dependancy

I want to perform a view shed analysis in QGIS using GRASS 7 r.viewshed. When I double click on r.viewshed in GRASS GIS 7 commands in the processing toolbox of QGIS I get the following message: ...