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Create a geography/geometry column from x and y fields - SQL Server 2008

I'm new in SQL Server 2008 and I hope you will understand my question/need. Thus, I have a table which contains 3 fields (Name, Lat and Long) in my data base (spatial). I want to create a geometry/geography column based on those fields (Lat and…
Tudor
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Generating random but believable digital elevation model?

Is there a way to generate a DEM, programatically or otherwise, that will feed into ArcGIS Desktop for further spatial analysis? Perhaps this needs to be broken down into smaller incremental steps: Generate a grid Fill grid with values where: 0 >…
Michael Markieta
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How to get the nearest point on a linestring to a given point?

I've been using PostGIS for a long time now but never had to use the LINESTRING geometry ...! :) Here's what I would like to do : I have a table of linestrings (representing streets of a given city, SRID 3395) and I would like to find the nearest…
Vivi
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Understanding difference between Coordinate System and Projection?

Can somebody please explain what is the difference between the Coordinate system (WGS 84 for example) and a Projection (Universal Transverse Mercator for example)? What is the difference between a projected coordinate system and projected CRS
marco
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What projection appeared in the NYTimes this morning?

Perhaps not as GIS related as some, but definitely about maps. Can anyone identify the map projection that appeared in the New York Times this morning? It's not one I've seen before, and a quick scan through Map Projections: A Working Manual did…
mattwigway
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5 answers

How to put GeoServer layers behind authentication?

I want to publish map layers using OpenLayers and GeoServer. While this is easy enough to set up, I'm a bit lost when it comes to authentication possibilities. What I want is to create different users that will, by logging in with their own user…
Mimo
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3 answers

Clipping raster with vector layer using GDAL

I have installed GDAL using the Osgeo installer. How can I clip a raster layer with a vector layer programmatically? Is there any GDAL API available which can help me with this? I am using Python.
Vicky
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3 answers

Poor performance with storing large rasters in PostGIS and visualising in QGIS

my question concerns the use and performance of several software tools in conjunction, namely PostgreSQL, PostGIS, QGIS, and GDAL. I'm a long-time ArcGIS, Python, and R user who is interested in diversifying into the free open source GIS ecosystem…
bcaradima
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4 answers

Bounding box for PostGIS table

Is there an easy way to get the bounding box for an entire table in PostGIS?
Ulrik
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3 answers

Exporting Feature GeoJSON from PostGIS?

I'd like to do a GeoJSON dump of a PostGIS table, but I want to export features (the geometry and the properties) not just the geometry. I've been digging into the ST_AsGeoJSON function but it looks like I can only get the coordinate information…
atogle
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What are my options for 3D web Maps?

I wish to have a Online 3D Map, which would show my Data, i.e both Raster and Vector, draped on a DEM that I have. Due to the requirements of using my own DEM & Raster data, Google Earth API is pretty much out of the running. Are there any projects…
Devdatta Tengshe
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In PostGIS is it possible to create a View with a unique ID?

When I create a view in PostGIS is there any way to add a unique ID to that view? Just like the "gid" field in any other PostGIS table? Edit: Sorry I should have included this in the original post. I am using PostGresql 9.0 and PostGIS 1.5. Ando
Ando
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Click Events with Leaflet and GeoJSON

How do I attach a click event to a GeoJSON that then executes an Ajax function when clicked. I looked into onEachFeature but that executes when the GeoJSON is loaded, not when clicked, thus executing a ton of ajax calls!
RustyShackleford
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Using OGR and Shapely more efficiently?

I'm looking for some suggestions about how to make my python code more efficient. Normally efficiency doesn't matter for me but I am now working with a text file of US locations with over 1.5 million points. With the given setup it is taking about…
GrantD
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What are the major differences between GPS, GLONASS and Galileo?

What are the major differences between GPS, GLONASS, COMPASS and Galileo?
JamesRyan
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