PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

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2
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2answers
345 views

Store GPS trace with timestamps, then interpolate location by time

I'd like to: Load a 1-second interval GPS trace (not GPX) into PostGIS Then query the table at sub-second accuracy (about 5Hz), and get PostGIS to interpolate the location by time. Is this ...
2
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0answers
106 views

Cartographic-complete Maps in PDF On Request using Open Source?

Currently I have some data in PostGIS. I want to implement the following: users will make a request via web, with parameters like location, scale, layers to be displayed, etc. and I need to provide ...
1
vote
2answers
81 views

How to get the geometry value from coordinates

I have a table with empty geometry column. I have two columns in the same table which has xcoordinate and ycoordinate values. I want to get the geometry value formed by these two coordinates. The ...
5
votes
2answers
442 views

Why is the Google Maps circle shape not matching to the distance calculated with PostgreSQL?

I am running a PostgreSQL 9.1 Database with PostGIS 1.5 extension. Several coordinates are stored in there with type GEOMETRY (SRID 4326). I'm building a web-application with Google Maps Javascript ...
2
votes
1answer
118 views

How do I get the vector and raster metadata from a PostGIS database?

im using php/postgres/postgis in a webapp, im wondering if its possible to get metadata from the db about all shp/geotiff table like (name, projection, type(ship/tiff), date, desc, owner etc ...) i ...
2
votes
1answer
141 views

PostGIS GML round trip confusion

I've investigated the issue of coordinate order in GML and each time I think I've got it but I find my self confused once again. I think some of my confusion may be to do with PostGIS. Doing a ...
1
vote
1answer
474 views

Delete duplicate geometry in postgis tables

After - I dont know what happend - all my entry's in my postgis tables are doubled! I tryed that to delete them but it does not delete any/all duplicates: DELETE FROM planet_osm_point WHERE ...
12
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0answers
261 views

Frequency of overlapping isochrones with map algebra in PostGIS

I have a table of polygons representing travel time isochrones on particular days. For each origin point, there are five isochrone geometries (stored in separate rows). For each origin point, I want ...
4
votes
2answers
203 views

How can I smooth or resample a DEM to find steep roads?

I am trying to find sections of road with steep gradients. My process is: pull a linestring from Openstreetmap data resample it to create a point every 10 metres look up the height data for each ...
0
votes
1answer
281 views

Print button greyed out on GeoExplorer

I have recently downloaded and installed the OpenGeo Suite from Boundless, and I am running through a few tutorials. I'm using GeoExplorer to manipulate layers defined in GeoServer (running from my ...
2
votes
2answers
825 views

How to export thousands of features from PostGIS to a single GeoJSON file?

I know how to export one feature from a PostGIS database using ogr2ogr: $ogr2ogr -f GeoJSON out.json "PG:host=localhost dbname=xxx user=xxx password=xxx" -sql 'select id, county, wkb_geometry from ...
1
vote
1answer
149 views

how to query contour postgres db for elevation at a point using postgis

Is there a way to interpolate between these contour lines for a given point using postgis? Thanks. I've come up with the following query to gather the potential contour lines of interest: ...
0
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2answers
157 views

How can I measure linestring on postgis?

I have a linestring and I want to measure this line. I try it on google maps. the result is that 0,65 km ...
1
vote
2answers
98 views

postgresql rule to trigger

I have two spatial tables and I am mirroring the data between the two table with a postgres rule: CREATE OR REPLACE RULE create_centroid AS ON INSERT TO csg.client_area_request DO INSERT INTO ...
1
vote
1answer
1k views

Downloading the distribute_setup.py

I need to download distribute_setup.py from the following website and the website seems to be broken, has anyone got an idea where else I can download this from? ...
1
vote
1answer
113 views

Get closest (source or target) of an edge from a point in postgres

I have a Postgres custom function that uses pgr_dijkstra to generate a route working. It works be passing the lat/lon of the start and destination points. I then find the closest segment vertice to ...
4
votes
1answer
187 views

artifacts in SRTM contour layers processed with GDAL tools and rendered with mapnik

Here is my workflow for importing individual SRTM tiles into postgis using the GDAL utils and rendering a png using mapnik: gdal_fillnodata.py -srcnodata -32768 gdal_contour -i 10 -a ele -snodata ...
0
votes
1answer
95 views

Split OSM highways at vertice

I am looking for a tool or query to split the OSM highways into multiple segments. Each segment should only consist of two nodes (start and end). I should do the same as described in this GIS ...
2
votes
2answers
124 views

finding the outermost border of a set of geomertries (circles)

I have a (large) set of geometries (circles) that overlap.! I would like to find the nearest location outside of this group from my current location. In this example my location is the black dot. In ...
1
vote
1answer
116 views

Creating new lines from existing lines based on points lying along the lines

I am pretty new to PostGIS and I have a problem I just can't figure how to start. I have a table of lines (id, name, the_geom) and a table of points (id, name, the_geom). Each point is located on a ...
1
vote
2answers
230 views

QGIS project with PostGIS layers freezes irregularly for minutes

I'm using about 30 more or less complex PostGIS layer in my QGIS project. Some of them are PlanetOSM layer generated with osm2pgsql. The Project loads fast (ca 5 sec). The canvas update by moving or ...
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vote
0answers
157 views

Import .gfs file into PostGIS?

Is it possible to import a .gfs file into PostGIS? I can open the .gfs file in QGis, so I assume it is a geographic file of some kind: but I'm not sure how to get it into PostGIS. I have Googled but ...
2
votes
1answer
121 views

ogr2ogr: Can I add a field when I import to PostGIS?

I have a bunch of GeoJSON files that I want to import to a PostGIS database. I can import individual files perfectly as follows: ogr2ogr -f PostgreSQL PG:"host=x user=x dbname=x password=x" ...
5
votes
1answer
468 views

PostGIS doesn't use index for spatial query

I can't get PostGIS 2.1 running on PostgreSQL 9.3.5 to use a spatial index even for the simplest queries. The whole dataset is 8 million points (population count grid from here ...
0
votes
0answers
129 views

Generate random points in geometry near heatspots

I have an algorithm, that generates random points with in a given polygon (Generate random points in polygon. Algorithm question). The Polygons the points are generated in are communities or districts ...
1
vote
1answer
398 views

How to refresh features on a OL3 map automatically?

I am using OL3 and GeoServer and PostGIS as database. My database is connected to GeoServer and OL3 conected to GeoServer and reads the points in database as vector layer and shows on the map. My ...
1
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1answer
468 views

osm2pgsql cannot connect to postgis database, running on a Bitnami project installer

Based on this guide I am trying to import an .osm.pbf file into my PostGIS database, which is running on my Postgres Bitnami installation here: [bitnami@ip-xxx]/usr/share/proj$ which postgres ...
0
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0answers
984 views

Intersection postgis TopologyException

I'm trying to make a quite simple analysis in Postgis, but I'm finding some problems. I want to in the first place create buffers for then, intersects themselves but one, this will be differenced. ...
0
votes
1answer
287 views

What should be my learning progress regarding GIS open source [closed]

I was wondering for a while now, what should be the hierarchy of my GIS knowledge or better to say, learning curve in domain of open source GIS. Should I start with Geoserver and PostGIS then ...
0
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0answers
132 views

How to split linestrings where start/end points don't touch nearby lines

I am trying to figure out some basic routing with PostgreSQL/pgRouting and I'm struggling a bit. Our network of linestrings are not topologically correct, tracks that should be connected don't touch, ...
1
vote
1answer
109 views

postgis resampling two rasters to a common grid system?

I am testing the PostGIS map algebra (ST_MapAlgebra) on two different raster tables. Each table contains a single image/row. They have the same SRID but different, overlapping extents and different ...
0
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0answers
29 views

PostGis: find distance if closer than X. For huge sets [duplicate]

I have two tables (that can have different geometry: point, line, polygons, ecc...) and I have to find distances: for all features in table A, for all features in table B, if feature is closer ...
1
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1answer
53 views

Is product purchaser in distribution area?

I am going to be using PostGIS 2 to create a lookup service. Given a point (lat/lon), I need to either find if a product can be distributed there, or b) a list of products or distributors. I am ...
2
votes
1answer
199 views

Solving “Traveling Purchaser Problem”

Till now, I was using PostGIS-pgrouting pgr_tsp function to solve Travelling Salesman Problems. This function can give us the best possible route depending upon the cost parameter when the starting, ...
0
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0answers
72 views

strange result of spatial functions postgis

I have a problem with different result of spatial functions for same geometry. For some reason result I get when I use geometry from database is different then result when I load same geometry from ...
3
votes
1answer
117 views

Layer from PostGIS with array of integers fields?

I have GeoServer 2.6 and I published a vector layer (point) which some of the field attributes are integer's array. GeoServer doesn't recognize those fields in wfs call or even in the Feature Type ...
0
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0answers
14 views

How to get linestringe from kml into shp or postgis [duplicate]

Im looking into extracting linestrings from a kml file into a shp file or postgis db. Each linestring would be a feature/row. How would I go about it usinge ogr2ogr or python? I'd like to get ...
0
votes
1answer
29 views

ogr2ogr - gpx to PostGIS has wrong timezone adjustment

A gpx track point: <trkpt lat="52.321775959804654" lon="-72.647269548848271"> <time>2014-10-01T16:07:19Z</time> </trkpt> is imported with ogrogr in my PostGIS ...
0
votes
1answer
58 views

OpenGEO templates and postGIS

I am trying to display my shapefiles.shp with ol3edit template. On OpenGEO Suite I have successfully created an ol3edit application.I'm in possession of the ol3editApplication.war but the ...
1
vote
1answer
75 views

Splitting multiline into several same-length multilines

Is there a method to convert a multiline geometry into several multiline geometries having the same length? For example break this: MULTILINESTRING((1 1, 3 1, 3 1.5, 2.5 1.5)) Into [approximately] ...
1
vote
0answers
182 views

Simplifying geometries and calculating non-spatial averages

I'm quite new to using proper spatial tools, and have a simple question that doesn't immediately show up on google. I have a table that contains multiple rows of empiric data (say, speed of a ...
1
vote
1answer
136 views

Visualize large amount of geopoints with Geoserver and PostGIS

I have a postgis database with over 50 million rows. Every row consists of a POINT corresponding to lon,lat and a value (number 1-100) I'm trying to create tiles for zoom levels 5-20 that I want to ...
5
votes
3answers
205 views

How can I export data containing umlauts from PostGIS to shapefile, without losing the umlauts?

I am exporting my Finnish (Finland) data from PostGIS to esri shapefile. I am using the PostGIS Shapefile Import/Export Manager and I don't see any way to specify the encoding of the shapefile's ...
0
votes
0answers
60 views

Overlapping gpx imported to PostGIS with ogr2ogr

I can successfully import track points from gpx file into my PostGIS database the usual way: ogr2ogr -f "PostgreSQL" PG:"dbname=ABC user=usrname password=123" firsttracklog.gpx However, I have a ...
1
vote
1answer
55 views

Index to speed up ST_HausdorffDistance?

When comparing similarity of linestrings with ST_HausdorffDistance (or another type of similarity function), is there a way to use an index to speed up the search for similar linestrings?
1
vote
1answer
212 views

How to import multiple shapefiles without any dbf to a postgis database?

I have a polyline shapefile (.shp and .shx) without .dbf. I would like to import the shp into Postgis. In order to do that, I created the corresponding .dbf using the r code provided by mdsumner in ...
3
votes
1answer
163 views

PostGIS Nearest Neighbour outside buffer

I am trying to find the 6 nearest neighbours to a point which are outside a defined buffer. Basically I am comparing points of the same table and working with Mike Gleason's examples. WITH subq AS ...
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0answers
148 views

Create a “wide” table recording all overlaps between polygons in PostGIS

I have a set of overlapping polygons and would like to record which polygons are overlapping at each intersection. I have followed the instructions at: ...
6
votes
1answer
501 views

SQL “Case” statement when count(*) is 0

I am trying to write the following SQL command using case clause. with x as (select the_geom as geom from table1 where st_dwithin(the_geom, st_setsrid(st_makepoint(28.959495,41.019913), 4326), ...
1
vote
2answers
750 views

Insert values in Postgresql in Java

Hello i try to insert same values in my table but i write this code String sql = "INSERT INTO points (gid, osm_id, name, type, geom)VALUES (?, ?, ?, ?,ST_GeomFromText('POINT(?, ?)', 2100));"; ...