15
votes
0answers
389 views

Calculating Focal Statistics for Special Neighborhood?

I'm looking to calculate focal statistics for each cell of a raster, within a neighborhood of a specified criteria. Background - I have three binary rasters, each representing a single vegetation ...
10
votes
0answers
404 views

Group polygon features to match a set of specifications

I have two different sets of polygon features (398 census tracts and 80 ZIP codes) that each roll up to a larger feature (a US county). Though census tracts are smaller than ZIP codes, they do not ...
10
votes
0answers
486 views

Geotransformation for polar stereographic?

I'm currently working to import CANGRID climate data (provided as Surfer Grid ascii, ".grd" files) into ArcGIS. The grid is 95 rows by 125 columns in size.Metadata provides lat/lon of origin (lower ...
8
votes
0answers
128 views

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS?

Every thing is in the title... I have a vector region in GRASS. And I would like to generate a vector (a polyline) beeing the bostrophedon pattern which fill this region. In the picture bellow, I ...
8
votes
0answers
134 views

Point sampling along a pole-wrapping coastline with PostGIS

I am working on a task that requires me to get sample points every 1000 km along coastlines, and have run into a problem with Antarctica. From what I can tell, it seems to be an issue with the use of ...
8
votes
0answers
255 views

ArcObjects running in Addin slower?

I have created a class library which does some geoprocessing. The addin calls a class that is an async process. I have ensured the thread is STA and the arcobjects are thread safe (ie. not passed from ...
7
votes
0answers
313 views

Using GRASS algorithms in Sextante under ArcGIS Desktop?

Sextante for ArcGIS comes with SAGA modules. I know that I can use GRASS algorithms in Sextante under gvSIG. But how can I use GRASS algorithms in Sextante under ArcGIS Desktop? I tried to look ...
6
votes
0answers
66 views

How to minimise number of dynamic pages to map scattered point

From time to time I have to produce mapbook to show points of interest. First step to create pages, using regular mesh: I don't like the solution because a) there are some pages with single points ...
6
votes
0answers
74 views

Best way to cut linestrings with points

i was checking the best way to cut linestrings by points. The scenario is: lots of streets, need the segments cut by intersect points, kind of this: I got linestrings (full uncuted by points) ...
6
votes
0answers
122 views

How to submit user scripts for Processing Toolbox (QGIS 2.6)?

QGIS 2.6 change-log says that now there is some kind of repository where users can submit their scripts to make them available for everyone. Unfortunately I was unable to find any details about how to ...
6
votes
0answers
214 views

Why does a z factor of 1 get turned into 0.999998 in my output

Just built a model that uses 3D Analyst - Surface Volume. I am trying to use a z factor of 1. Whenever I run the model my output table shows that a Z factor of 0.999998 was used instead of 1. I ...
6
votes
0answers
111 views

How to extract sublinestring from a linestring with overlapping segments

Problem statement: Given a bus route (defined as a linestring ln.the_geom), and a set of bus stop locations (pt1.the_geom,pt2.the_geom,...ptn.the_geom), divide the bus route into segments between bus ...
6
votes
0answers
713 views

Connecting ArcSDE to Quantum GIS for dummies?

I really have a need to be able to connect to and edit ArcSDE data in Quantum GIS. This question has been asked before and apparently is possible, but the instructions are just not specific enough ...
6
votes
0answers
88 views

Compute visibility graph on sphere

I have a PostGIS table with some polygons (stored using the geography data type). They represent regions on a spherical earth. For each pair of vertices chosen from among all the polygons, I want to ...
6
votes
0answers
361 views

Printing/exporting WMTS tile layer with desired resolution / zoom level in QGIS

I have a project which uses WMTS and some vector layers in QGIS. I can freely zoom in and out, and tiles are refreshed with appropriate zoom level, just as expected. Now I would like to export part ...
6
votes
0answers
946 views

Reprojecting WGS 1984 Web Mercator (EPSG:3857) in Python with GDAL

I am reprojecting rasters in python using GDAL. I need to project several tiffs from geographic WGS 84 coordinates to WGS 1984 Web Mercator (Auxiliary Sphere), in order to use them later in Openlayers ...
6
votes
0answers
281 views

Postgis - extrude a polygon

I want to extrude a polygon shape in postgis to create a pseudo 3D effect. To this end I have written a crude function to achieve it. This is very much test code and it creates a new Y vertice for ...
6
votes
0answers
566 views

Feature Service from plain PostgreSQL/PostGIS in ArcGIS Server 10.2

Using 10.2 ArcMap/ArcGIS Server on Windows I've successfully published some map services from my PostgreSQL/PostGIS data and now I want to enable editing the features through a JavaScript web app. ...
6
votes
0answers
171 views

Find and destroy duplicate OSM multipolygon/polygons in TileMill/PostGIS

In OpenStreetMap there are sometimes multipolygons where attributes are present on both the polygon and the multipolygon relation, such as the Grampians National Park: ...
6
votes
0answers
326 views

How to create a topologically correct dataset in PostGIS (with GRASS)?

I have shapefiles which I have loaded in postgis and now i am trying to use geometric function in postgis like ST_intersect and they fail because the data is not topological correct. I have tried to ...
6
votes
0answers
333 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
6
votes
0answers
2k views

ArcGIS 10 Rest services regulary stop working

I have a problem with a new installation of ArcGIS Server. The installation is ArcGIS 10 on Windows Server 2008r2 with IIS 7. I have followed this guide to configure the IIS ArcGISServicesAppPool: ...
5
votes
0answers
141 views

Can GRASS compute the line graph representation of an input graph?

I'm interested in computing a line graph for an input graph, preferably in GRASS since I'll be using other GRASS network analysis tools afterwards. I couldn't find any reference to line graphs in the ...
5
votes
0answers
100 views

PostGIS Recursive Query Based on Line Connectivity

I'm having difficulty with a query. I have a network of linestrings, each with a value in the n_type column. This can be one of a handful of options. I'd like to generate a new table that groups any ...
5
votes
0answers
112 views

Spatial query too slow to handle bigger OSM extracts

I'm trying to compute some statistics for OSM data using PostgreSQL 9.3.5 and PostGIS 2.1.4. I started with a small bavaria extract which I downloaded from Geofabrik. The db schema is the normal API ...
5
votes
0answers
77 views

FLAG - fuzzy landscape analysis in GIS

I am trying to identify wetlands using different topographic indexes, e.g. TWI/CTI. And I would like to try out a method called FLAG (fuzzy landscape analysis in GIS), but I don't really understand ...
5
votes
0answers
95 views

At surface reflectance values

I have calculated at sensor reflectance for a multispectral image and preformed atmospheric correction. The reflectance values for the visible and NIR bands are between 0.2 to 0.01 for surface eg veg, ...
5
votes
0answers
173 views

ArcObjects : Out of Server Memory when reconciling a large edit session

One of our users has been periodically experiencing 'Out of Server Memory' errors with ArcSDE 10.0 when trying to reconcile a large edit session. VMware ESX Instance: Windows Server 2008 R2 ...
5
votes
0answers
215 views

Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random ...
5
votes
0answers
267 views

How to compare two sets of points in QGIS?

I have two point layers with XYZ data; one set are points measured in the field and the second set is a Lidar data set. I want to check the accuracy of the Lidar in comparison to the measured data. ...
5
votes
0answers
84 views

Is there a limit to the number of polygon points you can export to CSV in QGIS 2.4?

Using QGIS 2.4 I am currently importing a csv file with ~30,000 polygons (polygons in WKT format). I also have a United States shapefile. I have used the Clip function to get only the polygons that ...
5
votes
0answers
194 views

Has anyone used ArcGIS for 'automatically' detecting lineaments from a high-resolution (1m) DEM?

I have a set of DEM's produced from LIDAR data. I am wondering if anyone is familiar with or knew of any published research papers which looked at (semi-)automatically detecting lineaments /or ...
5
votes
0answers
217 views

Performing cluster analysis in R with Point Datasets

I am a R-Beginner, but I want to use it for some spatial statistics. I want to check the relation between the occurrence of ill persons and the existence of water in a area of interest. To give you a ...
5
votes
0answers
115 views

Distribute QGis plugin which depends on certain Python packages

I developed a plugin for Qgis which depends on some Python packages. On Linux and Mac, this is not really a problem because I can easily install them with the system pip command. Windows is another ...
5
votes
0answers
200 views

Convert Graphics to Vector in QGIS

I am wondering if there is a way to convert a graphic produced from symbology in QGIS to a vector layer (ie: shapefile). I have a point layer with bearing direction in the attribute table. Following ...
5
votes
0answers
180 views

How to select features based upon multiple values in graphical modeler?

I'm trying to create a basic model using QGIS, the QGIS graphical modeler and the sextante toolbar. In part of the model, I need to select features based upon multiple attribute values (for example - ...
5
votes
0answers
433 views

R with ggplot2/ggmap - How to load a png image as a map

I am trying to find a workaround for ggmap's missing support of world maps (i.e. you can't create any maps that show latitudes > 80°, due to idiosyncrasies in the mapproj package). To a limited extend ...
5
votes
0answers
231 views

How to create a chart of elevation using points?

I am using shapefiles with basic information including the x-, y- and z-coordinates. I want to see how the objects (in this case points, which are finds from an excavation) are scattered along the ...
5
votes
0answers
366 views

How to convert a raster (array) to a NetworkX graph and do a * search?

I want to use a slope-raster for a a_star path analysis in NetworkX. I am using Python for this project. My test raster looks like this First I read in the raster with GDAL input_raster = ...
5
votes
0answers
364 views

Weather conditions forecasting / interpolation

I'm trying to carry out weather conditions interpolations. I have information of 92 weather stations for 800,000 km2. As you can imagine the extension of land is huge and I need some kind or weather ...
5
votes
0answers
397 views

How do I install Orfeo toolbox and Qgis 1.9?

I'm having a lot of trouble getting Orfeo toolbox and Qgis 2.0 working. I followed the qgis wiki instructios, added the ppa, installed qgis 1.9 (it's beautiful, great work!). But when i tried to ...
5
votes
0answers
511 views

Is Tomcat or Jetty a better container for Geoserver on Windows

My Understanding is that Geoserver can be run in the default Jetty Environment or in Tomcat on Windows Server 2008 R2 GeoWebCache uses Tomcat as its container in its installation instructions. Which ...
5
votes
0answers
172 views

Is GeoExt styler extension available for Geoserver 2.3.3?

I've switched from my older version of geoserver to geoserver 2.3.3. In the older version, the styler worked just fine, but I could'nt find a styler extension that matched the new version. I tried ...
5
votes
0answers
612 views

Using stat_density2d with coord_map in ggplot2

In my example I am plotting a shapefile for all England & Wales, however I'm interested in the greater London area. If I allow ggplot to simply default and display the entire shapefile then the ...
5
votes
0answers
114 views

Is there a way to label a layer using its file name or layer name?

Is there a way to label a layer using its file name or layer name (if I'd change it in Layers window TOC)? I tried some functions but I'm not good on that. I have lots of shapes (lines) and it would ...
5
votes
0answers
98 views

Estimation of values for unsampled points

I want to measure biomass on a coastal mudflat. I can only access points inside the polygon. Are there any methods available that would allow me to estimate values of the points outside of the ...
5
votes
0answers
534 views

How do I convert from SLD to Carto CSS?

I have a bunch of layers and corresponding SLD's running a WMS service. I was exploring the possibility of shifting to a TileMill's tile based TMS service. For this, I would like if it were possible ...
5
votes
0answers
846 views

Why is GDAL ECW compression much poorer than ECW compression from ERDAS

We use ECW compressor shipped with ERDAS Imagine to export Orthoimagery for our different departments. Because we are facing problems with the Imagine license server, we had to choose GDAL (built with ...
5
votes
0answers
165 views

Joining layers with respective elements with PostGIS Topology

Recently I have started using PostGIS topology extension, but I have some difficulties in understanding how the structure works: One of the key points is the use of "layer"s: as of what I understand, ...
5
votes
0answers
44 views

Where can I find more details about rasterFunctions?

I have published an Image service with ArcGIS Server 10, containing the results of an interpolation operation. The Image which is returned from the service is in greyscale. I wish to render it with ...

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