3
votes
0answers
76 views

Issue with dissolving a polygons layer in QGIS 2.4

I downloaded a dataset of roads and parks from OSM. I then buffered the roads and merged with the parks. Now - all i want is to dissolve / union all the features in the merged layer. I fail to do it ...
3
votes
0answers
66 views

Geoprocessing tool for finding specific point within polygon

I have a ArcGIS task and cannot find a solution. I try to find a certain point within a polygon (see picture). This example is handmade and I need a geoprocessing solution I point I try to get is ...
3
votes
0answers
45 views

Elevation interpolation along a (sewer) line

Here's what I want to do. I have a vector sewer line feature class that contaings a field for the high invert elevation and one for the low invert elevation. I can turn them into a raster no problem ...
3
votes
0answers
68 views

Postgis database query optimisation

I have a set of rasters in DTED format which I load into postgis database using raster2pgsql command line tool. Each of rasters is simply stored in a row and described by rid and a value of raster ...
3
votes
0answers
51 views

How to set up a base station without known coordinates

I am new to surveying, but need to set up a Topcon controller with Pocket 3-D to run 2 receivers and a grader running off the base receiver for my new job. It sounds stupid, because I can't seem to ...
3
votes
0answers
99 views

Open Trip Planner rest api request

following this tutorial I set up a Open Trip Planner (version 0.11.0) stand alone server. It works very well at http://localhost:8080/index.html and for example at ...
3
votes
0answers
37 views

Loading raster data into postgis database

i would like to add raster data to my postgis database. when i try to check if postGIS is responding to requests using the following command psql -c "SELECT PostGIS_Version()" ,i get an error message ...
3
votes
0answers
127 views

Formula for maximum coverage of a geostationary satellite based on earth station elevation

I am trying to create a javascript function to represent the maximum coverage of a geo satellite for different antenna elevations (0 degrees, 5 and 10 degrees) with 3 leaflet polylines. The result is ...
3
votes
0answers
25 views

How can ASTER elevation data be converted to a CAD model

I am trying to convert ASTER elevation data to a 3D CAD model using only opensource software. I have tried using different file formats but I have been unsuccessful. I use QGIS for my GIS work and ...
3
votes
0answers
50 views

Rotate map with dynamic display layer?

I am developing an application using the dynamic layer. However, I have trouble rotating the map (Not the same as rotating data frame by default). See more details: ...
3
votes
0answers
130 views

How to use Python's subprocess module in a for loop ArcGIS?

I am new to scripting with ArcGIS. Although this might be an easy thing for those that know Python well, I haven't figured out how to use the subprocess module in a script. I actually think I'm ...
3
votes
0answers
121 views

In QGis, why do parts of the OpenLayers layer export in a different scale and position?

I have a problem printing with google satellite maps in QGIS. In the composer it's all right, but in the pdf file some portions of the image are in a different scale and in a different position. An ...
3
votes
0answers
25 views

Error message retrieval in grass.read_command

I am writing a script in python and would like to get the error messages of the function grass.read_command for seeing why it is not working. I found a webpage ...
3
votes
0answers
185 views

Understanding Error network dataset has no edge elements It may be unbuilt?

I'm trying to alter an Integrated Transport Network (ITN) to remove all of the roads that are within a flood zone (a separate shapefile). The ITN Network Dataset I'm working with was created by ...
3
votes
0answers
30 views

Distortion in projected raster

I am having a frustrating problem with something that I think should be very simple. I have a number of DEMs from the National Elevation Dataset (NED), that come standard in the NAD83 coordinate ...
3
votes
0answers
46 views

ArcGIS Silverlight API - Use POST instead of GET

Is there a way to get queries performed using the ArcGIS API for Silverlight to use POST instead of GET? I'm trying to pass in a geometry which has too many vertices for the character limit.
3
votes
0answers
48 views

Lake Victoria bathymetric data

I am trying to find bathymetry for Lake Victoria (or portions). Any GIS format and almost any resolution will do. As a last resort a hydrographic chart will suffice.
3
votes
0answers
47 views

how can i save a satellite raster image as a layer file in arcmap 10.2

I am trying to save a raster satellite image from esri world imagery as a georeferenced layer file. i still want to be able to zoom in and out as i can when veiwing it through the server.
3
votes
0answers
87 views

Data Driven pages, printing from mapsets not working, ArcGIS Desktop 10.2.1

Well, it's almost a year on from when I first asked this question on the ESRI user "forum" - Data driven pages, ArcDesktop 10.2.1 - is there a limitation on how many pages can be printed? ESRI tech ...
3
votes
0answers
60 views

Create a Shape file from Sql dump file

I am trying to map data by querying a table called xyz. I need to show the the_geom data on the map. I have below query in my mapserver .map file: DATA "the_geom from xyz using unique id using ...
3
votes
0answers
58 views

Where do I find official summit elevations found on USGS topo maps?

I'm creating topo maps for my day hikes guides for national parks. I've already done one for Glacier National Park. When I was working on summits, I downloaded the data for Montana from GNIS and when ...
3
votes
0answers
57 views

How to perform mass-balance analysis with ArcHydro

I was wondering if there is any online manual/instruction for carrying out water mass balance analysis using ArcHydro? I have searched for such information, and the closest thing I can find is a ...
3
votes
0answers
70 views

Lining up polygon legend patches in ArcGIS for Desktop?

I have tried the properties and everything, I cant understand why my polygons are not lining up correctly in the legend. I created this legend the usual way by adding my 3 layers to the legend wizard ...
3
votes
0answers
31 views

Select stream network within a fixed distance from a point

Is there a tool out there that would allow me to select a portion of stream network that is within a fixed distance from a specific point on that network? In the example below, there is an ...
3
votes
0answers
66 views

Adding an offset to a Leaflet TileLayer on the fly

I'm currently using Leaflet to display 18th century maps of Belgium as a base layer with a vector overlay of the present day road system. Although the maps are absolutely gorgeous ...
3
votes
0answers
80 views

How to use WEKA J48 classifier for satellite image classifications

Basically I am trying to build a tool from WEKA software using the J48 classifier for automatic satellite image classification to build landuse land cover maps. Could somebody please help, as I am not ...
3
votes
0answers
108 views

ArcObjects Memory Leak with IWorkspaceEdit?

I have ArcGIS 10.1 installed. I have created a function for copying all of the features from one shapefile to another using IFeatureBuffer, now every time the function when it is called, it takes ...
3
votes
0answers
83 views

How to use real time data (traffic) for network analyst in ArcGIS?

I have a problem with using traffic data for routing. I'll describe the scenario: There is a local traffic service (real time) that has the speed of each segment in the network. This information is ...
3
votes
0answers
62 views

Sourcing free live traffic layers to use in MXD of ArcGIS Desktop?

I am looking for free live traffic layers for an ArcGIS Desktop 9.3 MXD. My searches haven't been that successful.
3
votes
0answers
71 views

Intersection of a vector linestring and underlying DEM

Following is an screen-shot where ASTER DEM raster layer has been overlaid by a road linestring vector layer. I want to extract those DEM pixels which are lying exactly beneath the linestrings. I want ...
3
votes
0answers
84 views

How to snap and move circles by the center?

I have a point layer, and a polygon layer with buffers of a given radius around each point. I need to move points, and check that each buffer is not above forbidden land/plots. In autocad, you can ...
3
votes
0answers
104 views

Batch export to shapefile by attribute field in QGIS

I have a project in QGIS where I am creating a map of plants over a large area. I want to take the "Genus" field (of which there are 100 hundred values) and essentially create 100 shapefiles based on ...
3
votes
0answers
25 views

3D distance and topography

I have a set of points and want to find out the nearest distance to a water body (poly lines) taking into account the terrain and get a surface distance calculation. I understand that the way is to ...
3
votes
0answers
50 views

Questions about SRTM , .hgt format and the sea level/coastline

What a nice place here ! The questions/answers system is very elegant. I have read and get some useful informations allowing me to write a little .hgt reader... I am working on C.G.I and create 3d ...
3
votes
0answers
37 views

Raising raster to a power gives no data values

When performing the following operation in QGIS Raster calculator: 10 ^ (("20091201_20100101_chl_modis_malvinas_ns@1" * 0.0000581)-2) I get no dada values for every cell where I should get < 1, ...
3
votes
0answers
23 views

What's the difference between coordinateDimension and spatialDimension?

The OpenGIS standard mentions three methods to query the dimensions of a Geometry: dimension(): the inherent dimension of the geometry: 0 for Point 1 for Curve 2 for Surface coordinateDimension(): ...
3
votes
0answers
387 views

How to extract elevation data Google Earth?

How do I extract multiple elevation values for a particular area in Google-Earth all at once? I've only been able to manually pick them one by one when I enter the long. and lat. for each point.
3
votes
0answers
323 views

Downloadable, Open Source, IP GeoLocation database

I have an open source project I need a similarly open source IP GeoLocation database for. i.e. IP address to country (and ideally city). Ideally with a license that allows redistribution. This is a ...
3
votes
0answers
59 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 ...
3
votes
0answers
47 views

How to detect temporal changes using ArcGIS?

I want to show urban sprawl in a city over ten year period. I took a MOOC on geospatial revolution, therein a link was shared to do such analysis. I just want to show the urban sprawl, nothing ...
3
votes
0answers
41 views

Overriding the QGIS Feature Dialog

We are developing a QGIS plugin and would like to override the QGIS Feature Edit Form with our own Dialog. Have explored using setEditForm and setEditFormInit, but the init process appears to want to ...
3
votes
0answers
90 views

Pulling ArcSDE feature classes from current map to fieldmapping as DETable?

I'm working with SDE layers in arcmap. trying to avoid pointing to the sde file itself. I've tried workspace.Pathname, it was empty for sde remote workspace. I've also tried IName from workspace, ...
3
votes
0answers
25 views

How do I drag item/file from ArcCatalog to custom UI form created with Toolbar Add-in?

I have created a button add-in in ArcMap that pops up custom UI/Form. I want to drag and drop file from ArcCatalog into the textbox on the Form. I am able to do so with windows explorer but not from ...
3
votes
0answers
51 views

How long should a delete identical take on ArcGIS 10.1

I have a 3.25 GB feature class of polygons with a spatial index. I am using the delete identical tool comparing the shape and one other field which contains a text string of 9 characters. The tool ...
3
votes
0answers
44 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 ...
3
votes
0answers
54 views

Default folder structure in ArcGIS for Server?

I'm very new to ArcGIS so I'll appreciate any pointers in the right direction, to documentation, etc. I anticipate having to develop a front-end for an ArcGIS server, and until it's ready I've just ...
3
votes
0answers
229 views

Extracting flow accumulation to stream shapefile

I would like to create a shapefile that displays the flow accumulation for a given point in a stream channel. Is this possible? My client wants a map that shows the accumulated flow/catchment area ...
3
votes
0answers
103 views

Cost Path: multiple pairs of sources and destinations

I have seen many questions related to this problem but very few answers. I am very new to scripting and using ModelBuilder, but I am trying to calculate the cost path for 200 polygons with a single ...
3
votes
0answers
93 views

How to compute (X,Y,Z) of a point from given attributes

Is there a way to compute the geodetic coordinates (Earth Centered) of a satellite S(x,y,z). The original problem is to compute the footprint of an antenna, given the following information: ...
3
votes
0answers
88 views

Create vector grid from canvas using script

I've modified "Hex grid from layer bounds" script to my need. Just added cellsizex and cellsizey. Changed the hexagonal - 3 to "1" to make it as a square grid. Is it possible to include an option to ...

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