5
votes
0answers
158 views

How to speed up simultaneous working with PostGIS layers in QGIS?

we are working on one big layer at the same time (10-20 people). Some of us use QGIS 2.8.1 and the other 2.6. The user with 2.8 have a lot of crashes (QGIS). The 2.6 users don't have this crashes but ...
5
votes
0answers
205 views

can I preserve a fading alpha layer when mosaicing images with gdal?

I am mosaicing some images with gdal and would like to improve the final result by using a fading / gradual alpha layer towards the edge of each image to remove the sharp edges in the middle of the ...
5
votes
0answers
320 views

Any Examples of D3.brush() used with Leaflet?

I have a leaflet map that I have placed an SVG "on top of" using the leaflet overlay pane. I want to add a D3 brush to the overlay pane that will then update a separate chart. I've looked around for ...
5
votes
0answers
702 views

RGB satellite image in Python with Basemap

Can anyone recommend a workflow or python library that will let me work with RGB images and BaseMap (or something equivalent - could be CartoPy). I have Landsat 8 images, and can load one in python ...
5
votes
0answers
669 views

How to stop a PyQGIS script that has an infinite loop, using the keyboard?

So i wrote a script that does what i want over and over again using a "while True:" in a certain time interval (every 5 seconds using time.sleep(5)). So far so good BUT when i want to stop it i just ...
5
votes
0answers
146 views

How do I open MOD17A3 in ENVI such that it is properly georeferenced?

I am using ENVI 5.1 on Windows 8. I am trying to open a MOD17A3 (MODIS Net Primary Productivity standard product - L4) .hdf file which I downloaded from the USGS website. I am still a beginner at ENVI,...
5
votes
0answers
100 views

Is it possible to add an ArcGIS attachment to a row in Oracle using oracle stored procedures?

So far I have been able to attach files to features within a featureclass using the python tools and ArcObjects. Within Oracle I have been able to add features with geometries using the ST_Geometry ...
5
votes
0answers
79 views

QGIS Cross Section Profile Distance using Ellipsoid?

I am working with QGIS 1.8 and 2.6 and can't get any of the Cross Section Profile tools to provide the ellipsoid ("proper") distances. All the distances use geographic coordinates which are too long/...
5
votes
0answers
107 views

Diminishing performance of gdal_polygonize in a python subprocess for GRASS to PostgreSQL

I have written a python script to polygonize GRASS rasters into a PostgreSQL database using the gdal utility gdal_polygonize: sub.call('gdal_polygonize.py -8 gdb/quercus/{0}/cellhd/{1} -f "PostgreSQL\...
5
votes
0answers
131 views

Publishing mosaic dataset to image service

I'm having problems publishing a mosaic dataset to an image service. While I can publish a service, the result does not carry over the pixel values (every cell is valued at 1.134274E+38). Strangely ...
5
votes
0answers
99 views

Generate a series of ellipses on a line

I am trying to create a series of ellipses (mocked up in green below) of defined dimensions along a line. I have got as far as generating regularly spaced points along the line that are attributed ...
5
votes
0answers
640 views

QGIS 2.4.0-Chugiak: How to threshold NDVI to calculate emissivity for land surface temperature

I am analysing urban heat island using thermal band 6 of landsat TM-5 sensor with respect to Normalized difference vegetation index that derived from the Band 3(Red) and Band 4(NIR). Lansat TM years ...
5
votes
0answers
122 views

What Does the Cell Value in a Composite Raster Mean?

When I make a composite raster in QGIS using the GRASS r.composite tool and then click on a certain cell I get these values in the blue/green/red/composite rasters: blue = 124 green = 124 red = 172 ...
5
votes
0answers
64 views

Access multiple rasters with GeoServer

I am curious if anyone knows if, and how, it would be possible to configure GeoServer to provide download (GetCoverage) capabilities to multiple adjacent rasters. A GeoServer mosaic comes close, but ...
5
votes
0answers
90 views

Null Values in Geographically Weighted Regression Analysis

Some of my explanatory variables have a few null values for certain polygons. Can GWR handle these, or should I remove the whole polygon and all data (dep, ind variables for that particular polygon)? ...
5
votes
0answers
101 views

Resampling air temperature gridded data to sub-grid resolution

I'd like to obtain a 30-m resolution gridded dataset of air temperature from the ~1km gridded data of WorldClim, of Hijmans et al., 2005) for a mountainous region. The easiest procedure (I thought ...
5
votes
0answers
217 views

Is there a limitation on the numbers of layers that can be displayed in QGIS?

I have been looking for an answer to this question for the last several weeks, so hope that someone here has encountered the same issue and has a viable solution to my problem. I am currently using ...
5
votes
0answers
187 views

GeoServer ImageMosaic PostGIS index update

I use GeoServer where I created an ImageMosaic storage following this manual. When I create new datastore, all *.tif files are indexed into DB (PostgreSQL with PostGIS). How can I create new index in ...
5
votes
0answers
206 views

Validating range domains when editing feature service in ArcGIS Online?

I have a feature class and a range domain is applied to a field. I know we can use the "Validate Features" command for validation. My question is that when the feature class is published to ArcGIS ...
5
votes
0answers
281 views

How do I parse the file format for attributes in Raster Product Format (RPF) maps and imagery?

I'm trying to implement an open-source NITF reader (using only java, no external libraries such as GDAL or NITRO), and its mostly going OK. However I'm having trouble understanding the RPF extensions, ...
5
votes
0answers
185 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
141 views

Servers that implement OGC Geo/Time OpenSearch

The OGC is close to publishing the "OpenSearch Geo and Time Extensions", which can be downloaded from http://www.opengeospatial.org/standards/requests/116. That specification is based on, but extends, ...
5
votes
0answers
368 views

sql server spatial index performance

I have a table with around 2 million records in it. I create a spatial index, using the defaults other than the bounding box. I've been noticing that some queries are extremely fast, and some are ...
5
votes
0answers
247 views

How do I simplify the straight sections of (multi)Linestring in PostGres/PostGis leaving the curved sections untouched

I have (multi)linestrings containing upwards of 5000 points and I want to perform two simplifications possibly using Ramer Douglas Peucker or alternative methods in PostGis The (multi)linestrings ...
5
votes
0answers
521 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 = "slope5....
5
votes
0answers
502 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
570 views

Finding poi using st_dwithin in postgis

I am not familiar with gis or writing sql, so my understanding in this field is lacking. I have a hundreds of lat/lng geographic coordinates stored in a single table called Places like this: ID | ...
5
votes
0answers
279 views

QGIS does not read ESRI Geodatabase correctly

I have a geodatabase from the EPA that does not seem to me reading correctly with Quantum GIS. QGIS Version 1.8.0 (Lisboa) and GDAL/OGR 1.9.2 When I open the attribute table the first two columns ...
5
votes
0answers
183 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
866 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
544 views

Find points that fall within a radius using Hibernate Spatial

I am using hibernate spatial and postgis and i want to find the points that fall within a certain radius. Using this SQL: SELECT name FROM institution WHERE ST_DWithin(geom,ST_GeographyFromText('SRID=...
5
votes
0answers
346 views

Constructing a Voronoi diagram using a complicated travel time metric

I have in my possession four sets of shapefiles: 1. Locations (points), around 1000 2. Roads (lines), each road has a speed attribute 3. Terrain (polygons), each zone also has a speed attribute 4. ...
5
votes
0answers
2k views

How to open File Geodatabase in QGIS (Ubuntu)?

So far I have found instructions on stack exchange but they are for windows. And so far the information I have found is for windows. I currently have Ubuntu 13.04 Raring tail. I am using qgis 1.8. I ...
5
votes
0answers
101 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 polygon,...
5
votes
0answers
267 views

How to write an address search plugin?

I am migrating some users from MapInfo to QGIS, and before they sign off on it, they want a very simple address search in the same way that we currently have one working in MapBasic. I;ve been having ...
5
votes
0answers
1k 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
337 views

GPS data based track/trip calculation algorithm available?

Currently I'm receiving position data of moving assets every 90 or 120 seconds (depending on the asset). What I'd like to achieve now is to detect standstill and movement phases (tracks/trips) on the ...
5
votes
0answers
410 views

Tilestache/Mapnik: Is it possible to create dynamically filtered layers?

I'm using Tilestache to generate two layers with the mapnik and mapnik grid providers, and it's working great! However, I want users to be able to filter the data over many (more than ten) dimensions,...
5
votes
0answers
333 views

Geoserver create SqlView Layer with Geoserver Manager

I would like to register a new sql view layer to geoserver through the rest api. I am using geoserver-manager. The registration is ok, the layer is working fine, except wms getFeatureInfo, which ...
5
votes
0answers
793 views

ArcGIS Kernel Density with polyline, search radius / bandwidth calculation

I'm conducting a density analysis of a series of polylines and I'm hung up on determining an appropriate search radius. The default calculation performed by arcgis is to take the shorter dimension ...
5
votes
0answers
127 views

Is IGraphicTracker leaking memory?

It seems that when geometries are removed from an IGraphicTracker instance, the geometries remain in memory until IAoInitialize.Shutdown() is called. I have tried removing the geometries by calling ...
5
votes
0answers
384 views

Plugin Workspace: when to close an OleDbDataReader?

I'm developing a plugin workspace for ArcGIS. Internally, the plugin uses an OleDBconnection. All of the sample code I see seems to stress the importance of closing and disposing the connection. ...
5
votes
0answers
138 views

Why doesn't Polygonizer copy the line ids to my polygonized shapefile?

I am trying to convert a line shapefile into a polygon shapefile using Polygonizer plugin, and when my new polygons are created all the cells in my id field are "Null", although I have clicked "copy ...
5
votes
0answers
188 views

Advanced GMaps directions

I try to create an application for taxis. The application will be GMap based. On the map will be marked the region in which the taxi driver is working in. The region will be a polygon designed by ...
5
votes
0answers
807 views

Evaluating map projection scale error

This is related to a previous question I posted. I am trying to quantitatively evaluate scale distortion associated with choosing different projection center, center azimuth, and scale factor values ...
5
votes
0answers
354 views

convex hull over selected features

I am trying to achieve a convex hull over a feature Set returned by a query. But have been facing the error below which i am not able to figure out In order to debug to see how the convex hull works ...
5
votes
0answers
397 views

How to convert a set of points to a solid object?

I have a data generated as the output of some numerical processes. I need them to be converted into 3D solid objects (as CAD solid format) to make them importable for some particular numerical ...
5
votes
0answers
878 views

How to find layer ID and name from Identify query using ArcGIS Web ADF?

I need to retrieve the layer ID of every layer returned by the IQueryFunctionality.Identify function (I am using ADF with .NET) Identify function spits out a DataTable array for layers which have ...
5
votes
0answers
802 views

How to use Route Task in Network analysis tools

I am using esri network analysis tool and I just want to draw the path between two clicked point on the map (by using route task) I use the example code block in the following link http://help....
4
votes
0answers
35 views

How to show labels exactly around a circle in QGIS?

I found an interesting way of proportional symbol mapping and labeling, I think this was made by Adobe Illustrator but I couldn't find out if it can be done in QGIS. What I am interested in the most ...

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