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1500 questions
28
votes
3 answers

What is difference between ArcSDE and spatially enabled databases?

When would you want to use ArcSDE (available as ArcGIS Server Basic license level) versus a spatially enabled database? What are the trade-offs on either side? What are the benefits on either side?
TheSteve0
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28
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8 answers

Calculating area in km² for Polygon in WKT using Python

I have polygons in WKT that looks like this POLYGON ((24.8085317 46.8512821, 24.7986952 46.8574619, 24.8088238 46.8664741, 24.8155239 46.8576335, 24.8085317 46.8512821)) I would like to calculate the area of this polygon in km². How do I do this in…
amaatouq
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28
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2 answers

Mixing geometry types in one PostGIS table

I'm faced with the following problem. I have to migrate from Oracle database to PostgreSQL+PostGIS. Currently all geometries of all types are stored in one table and each record contains a "lid" field which indicates features of the same layer.…
drnextgis
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28
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18 answers

Seeking full list of ISO ALPHA-2 and ISO ALPHA-3 country codes?

I'm searching for a full list of countries with their country codes. Like on this page (need full and valid): http://www.nationsonline.org/oneworld/country_code_list.htm
Lampard
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27
votes
5 answers

ArcGIS REST vs. SOAP API

When is it appropriate to use the ArcGIS Server REST API vs. the SOAP API and vice-versa? What do you see as the advantages of one over the other? For example, the SOAP service can be consumed as a Service Reference to integrate into Visual Studio.…
Britt Wescott
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27
votes
6 answers

What LiDAR processing tools are available in Python?

I have been using FUSION and the command line FUSION Lidar Toolkit (LTK) to process LiDAR data. A broad Google search ("Lidar Python") yielded libLAS and pyLAS as Python LiDAR libraries, however, these appear to provide only read and write access to…
Aaron
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27
votes
3 answers

Creating spatial tables with PostGIS

In the PostGIS documentation it says that there are two steps to creating a spatial table with SQL: Create a normal non-spatial table. Add a spatial column to the table using the OpenGIS "AddGeometryColumn" function. If I followed the examples,…
BenjaminGolder
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27
votes
2 answers

Choosing IDW vs Kriging Interpolation for DEM creation?

I'm trying to create a DEM using point data spaced very regularly about 10m apart. The area I am interpolating is an educational facility with many flat parking lots and football fields but still has some fairly steep hills that will often plateau…
Calavin
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27
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1 answer

Calculating Flow Direction and Delineating Basins from Projected vs. Unprojected DEM Data

This is somewhat of a theoretical question stemming from some discussions with colleagues on the topic of implications with delineating basins with projected (e.g., Albers Equal Area) vs. unprojected (NAD 83) data derived from a 10m DEM that's in…
MapBlast
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27
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6 answers

Programmatically retrieving Landsat 8 Satellite Images?

I have not been able to find out this myself, but is there a way to programmatically access Landsat 8 Satellite Images? I know that I can go to USGS EarthExplorer to search and browse through the scenes, and even download them. But I do not want to…
Frank
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27
votes
5 answers

List of central coordinates (centroid) for all countries?

I need a list of the central points (centroid) for all countries: China: lat/long (coordinates of the most central point in China) France: lat/long (coordinates of the most central point in France) etc...
seinecle
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27
votes
7 answers

Alternatives to Network Analyst

If I am looking to build a network based on road features and attributes, is Network Analyst my best bet? Is it my only bet? The world of FOSS (Free and Open Source) is new and exciting to me, but I find it difficult to navigate as a newbie. My…
Nathanus
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27
votes
7 answers

Geocoding APIs comparison

Is there a good updated source for comparing existing Geocoding APIs (i.e. Google, MapQuest) and their features? I'm really interested in their language support as well. For example, Google has libraries for its Geocoding service in JavaScript,…
TomSchober
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27
votes
5 answers

Optimizing osm2pgsql imports for OSM data

I'm currently building an instance on EC2 on which to import the entire Planet.osm snapshot of the whole Earth's worth of data for some projects we're working on. I've spun up a large Ubuntu x64 instance and attached plenty of separate storage on…
colemanm
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27
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4 answers

Listing all feature classes in File Geodatabase, including within feature datasets?

From python how can I build a list of all feature classes in a file geodatabase (*.gdb), including inside feature datasets? The standard example only lists feature classes at the top level of the geodatabase: import arcgisscripting, os gp =…
matt wilkie
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