Questions tagged [srid]

A Spatial Reference System Identifier (SRID) is a unique value used to unambiguously identify projected, unprojected, and local spatial coordinate system definitions

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votes
2answers
7k views

What is the SRID of census.gov shapefiles?

I downloaded the county files from: http://www.census.gov/cgi-bin/geo/shapefiles2011/main I cannot figure out what SRID to use with them. When I am trying to generate a class file from ./manage.py ...
3
votes
1answer
867 views

PostGIS 2.0 ST_Transform with Rasters cannot find custom SRID

I'm trying to calculate an average value in a buffer around a point. Given a raster in EPSG 4326 and a similar point, this is fine, except that the values will be skewed as they are not projected in ...
3
votes
1answer
2k views

How to transform SRID 3035 to SRID 4326?

I have data in the ETRS 89 LAEA format (SRID: 3035). But I have problems to transform it. Example data: N2736 E4541 I want to transform it to WGS84 (SRID: 4326), to check the coordinates on a ...
9
votes
4answers
4k views

Understanding concept of Spatial Reference System?

I am trying to understand the concept behind the Spatial Reference System. Why is it used and what is so specific about the SRID number? I went through many definitions and almost all went over my ...
2
votes
2answers
4k views

Problem when calculating longitude and latitude for points

I have a PostGIS database with SRID=900913 (Google Mercator) and I would like to know the latitude and longitude of points. I use this command: ST_X(ST_TRANSFORM(the_geom,4283)) Following what is ...
5
votes
1answer
13k views

How to get the coordinate system from a PostGIS database?

My question is probably amazinlgy stupid, but I can't find the answer myself. I would like to extract from a database the latitude and longitude of points. For now, I'm getting x(the_geom) and y(...
5
votes
3answers
843 views

which map projection should I use to calculate distance in Poland

I'm using/learning geodjango + postgis, and I'm trying to calculate distance between 2 cities in Poland. First using WGS84/4326 I define 2 points, and then after transforming this points into ...
1
vote
1answer
891 views

Inconsistent Spatialite Update Behavior; SRID not allowed?

I have two tables: crime and (police) stations. The latter has only 4 records with (name, lat, lng) fields. The former has over 500K records with two California Zone 2 (ft) coordinate columns named ...
5
votes
1answer
11k views

Transforming geometry coordinates from SRID 4326 to SRID 3011 [duplicate]

In SQLServer geometry field, I want to change the coordinates of geometry from one spatial reference system to another spatial reference system (from SRID 4326 to SRID 3011) by using ST_Transform. But ...
15
votes
3answers
39k views

How I get SRID from Geometry field

What is the function for getting SRID from Geometry field. I have inserted a shapefile into SQL Server table with a Geometry field defined. I know the projection of shapefile is Swreff99_1800 (EPSG:...
1
vote
1answer
859 views

Choosing best projection/SRID

I created a shape in OpenJump and exported it to shape(ESRI) file and then imported it to SQL2008 via shape2sql , the problem is that it shows bigger than what I want, In OpenJump it shows 1meter ...
1
vote
1answer
186 views

Get relative north aligned point 2163 (US Equal Area)

What I'm trying to do is create a grid where the y axis is north aligned. I have a origin Lat/Lon point which is the bottom left corner of the grid and each cell should be 100 by 100 meters. So I ...
3
votes
1answer
508 views

How to mix coordinate systems in GeoDjango?

This is a beginner question about working with different coordinate systems in GeoDjango. I've got a GeoDjango object with a polygon field, stored as OSGB coordinates: class Region(models.Model): ...
38
votes
6answers
20k views

Shapefile PRJ to PostGIS SRID lookup table?

I was wondering if there is such a thing as an shapefile PRJ to PostGIS SRID lookup table? Something that can translate the most standard shapefile PRJ definitions into the likely SRID. When using ...
7
votes
2answers
6k views

ogr2ogr srs options: where is the well known definition determined?

In the ogr2ogr documentation it says that when using -a_srs srs_def: Srs_def can be a full WKT definition (hard to escape properly), or a well known definition (ie. EPSG:4326) or a file with a WKT ...
7
votes
1answer
3k views

How do I get a country border data set into my geography column?

I have a PostGis database with a multipolygon geography (as opposed to geometry) column. I'd like to fill it with the country border data available from http://thematicmapping.org/downloads/...
13
votes
4answers
4k views

Looking for a pythonic way to calculate the length of a WKT linestring

I was quite unsatisfied with Calculating Length of Linestrings in WGS84 in Miles. It kept me wondering if there is a more convenient, Pythonic way to calculate the length of a WKT linestring according ...
19
votes
4answers
16k views

Is it possible to reproject spatial data using SQL Server?

SQL Server takes an SRID when creating spatial data, but is it possible to retrieve with a different SRID translating the coordinates? For example, let's say I have a bunch of spatial polygons using ...