A reference framework consisting of a set of points, lines, and/or surfaces, and a set of rules, used to define the positions of points in space in either two or three dimensions.

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5
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2answers
684 views

Identify the latitudinal and longitudinal point directly beneath an object in space

Given the azimuth and altitude / latitude and longitude from the observer to the satellite, how can I accurately find the latitude and longitude of the point of intersection directly under the ...
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1answer
326 views

ogr: how to use epsg database for RD New projection?

I'm trying to assign this EPSG projection to my newly created shapefiles using ogr. The OGR Projections Tutorial says: ...any geographic coordinate system in the EPSG database can be set by it's ...
4
votes
4answers
236 views

How to measure without coordinates?

My current Project is to "map" a turntable in qgis. I know, very unlikely but that's what my teacher wants. My teacher also wants me to measure something in this project (Very specific, isn't it?). ...
1
vote
2answers
973 views

shape file coordinate system

I added a shape file of Iran to Qgis. 'Tehran' has 35.6833° N, 51.4167° E coordiantes, however Qgis shows Tehran with 4772860,31296767. How i can view coordinates of a city or location in latitude ...
2
votes
2answers
663 views

How to use the coordinate system in arcgis 10?

I have a favor to ask. I have a few layers. The layers have been made by a different company. So how do I combine them all together so that they have the same coordinate systems? If there are any ...
1
vote
2answers
473 views

UTM coordinate conversion to Geographic coordinates

I have about 500 separate files containing GPS points in UTM coordinates from multiple zones. I am looking for a simple and fast python or Php script that i can use to carry out a batch conversion ...
4
votes
1answer
421 views

How to specify coordinate reference system (CRS) for scalebar that is different to project CRS?

Is it possible to specify a coordinate reference system (CRS) for the scalebar that is different to the project CRS? For example, my project CRS uses geographic coordinates (lat/long), the reason ...
2
votes
1answer
1k views

Why is my .prj file not being read by QGIS?

First off, I am new to GIS. I am using qgis (1.8.0), and have been given a shapefile containing .shp, .prj, .shx, .dbf, however qgis will not load the .prj file stating an invalid data source. ...
2
votes
3answers
2k views

Problem with spatial reference system / shapefile projection

I am new to using QGIS and having some problems getting some shapefiles to project correctly. I am using publicly available shapefiles for New York City municipal boundaries found here: ...
2
votes
3answers
1k views

Local Coordinate to Geocentric

The ultimate question, I need a transformation matrix to take a point in local space representing a roughly 500m x 500m place in New Mexico centered at -108.619987456 long 36.234600064 lat. The final ...
0
votes
1answer
178 views

How do I reproject a arbitrary coordinate system grid to OSGB

I have a polygon grid of a certain shape that has some data associated with it. Unfortunately its not properly projected, being in what seems to be an arbitrary scale and coordinate system (it was ...
2
votes
1answer
709 views

Convert shapefile in NAD27 from meters to decimal degrees to match xy data?

I have a shapefile of a boundary (polygon) that has the following projection: NAD_1927_UTM_Zone_11N Projection: Transverse_Mercator False_Easting: 500000.00000000 False_Northing: ...
2
votes
0answers
362 views

PostGIS: ST_Transform function conversion problem

I'm inserting map data from a GML file with srid EPSG:27700 into a PostGIS database table with srid EPSG:4326. I'm using the ST_Transform function as in this snippet: ...
2
votes
2answers
280 views

Ordnance Survey osgb:BNG spatial reference system not recognized by PostGIS

I'm trying to load an Ordnance Survey GML file into PostGIS using the ST_GeomFromGML function. The problem is that the spatial reference system that is used in the file, osgb:BNG, is not recognized by ...
1
vote
0answers
25 views

Translate geographical coordinate [duplicate]

Possible Duplicate: Calculating Lat/Lng X miles from point I would like to know how could I translate a geographical coordinate to an specific distance. So for example let's suppose I'm ...
1
vote
3answers
353 views

How can I translate a GML definition of SRS to a usual format (e.g. WKT or PROJ.4)?

From GDAL 1.9.0 a new utility is available: gdalsrsinfo. Although it can yield an XML (GML-based) definition from a source equivalent format or file, it seems that it can only read usual GDAL/OGR ...
3
votes
1answer
187 views

Natural Earth: How to get the position of each country?

I've just split the 1:10m Natural Earth countries into individual JSON files which I plan to render and partially stitch back together using RaphaelJS. The 1:10m map is very big (10mb or so) so ...
5
votes
2answers
629 views

What is the origin of the Degrees, Decimal Minutes format?

In my experience, for most non-GIS folks, the most commonly used and understood coordinate system is good old Latitude and Longitude, displayed as degrees, minutes, and seconds (DDMMSS.ss). In GIS, ...
0
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1answer
191 views

Spherical Mercator to Cylinder mercator?

Hello I want to create an overlay for google maps. As far as I know google maps using Spherical Mercator, so the system where I read the maps use Mercator but is not specified which (spherical or ...
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4answers
2k views

How to plot a point on a static Google map [png]?

map&markers=color:blue%7Clabel:S%7C40.702147,-74.015794&markers=color:green%7Clabel:G%7C40.711614,-74.012318&markers=color:red%7Ccolor:red%7Clabel:C%7C40.718217,-73.998284&sensor=false ...
3
votes
0answers
63 views

How can I specify a spatial reference system which has a north pole different than the standard north pole?

I have a geographic spatial reference system (i.e., latitude and longitude) which has a north pole that is not the usual north pole: it's the magnetic north pole at approximately 70.30 degrees north, ...
9
votes
2answers
1k views

How can I convert geomagnetic coordinates to geographic coordinates without doing the math myself?

I have some data which are in geomagnetic coordinates; that is, they are latitude and longitude, but in reference to the magnetic north pole in Canada rather than the geographic north pole. As you ...
1
vote
1answer
956 views

GeoToolKit conversion from lat/long to UTM

What is the proper way to convert lat/longs to a UTM coordinate system using the Java geotoolkit API? I have not worked with GIS software before, so maybe what I am trying to do is not directly ...
2
votes
0answers
176 views

How to decode Magellan URL coordinates to lat/lon

Magellan uses this URL to designate a coordinate in New York: mgn:///address/?coord=merwFvlqbM,name=Viva%20Herbals%20Pizzeria,number=179,street=2nd%20Avenue,city=New%20York,country=US How can I ...
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vote
3answers
2k views

How to convert Lat & Long from Onemap.sg to Google Maps

I have a set of address for Singapore, I would like to take the Lat & Long from onemap.sg (SYV21: X, Y / Easting, Northing) and then store it in my databse , convert into (WGS84: Longitude, ...
5
votes
3answers
103 views

Please help me identify this CRS. How could I identify this myself in the future?

I'm trying to georeference this map, but I don't recognise the CRS. It is for a region of Tanzania. Here is the image on imgur in case Stack Exchange compresses the image. How would I go about ...
0
votes
0answers
106 views

How to determine Earth co-ordinates?

I just read about latitudes and longitudes. I read latitudes are imaginary lines that run around the earth and longitudes are lines that run around from top to bottom. Using this system: 1. ...
8
votes
1answer
1k views

Computational most efficient way to convert Cartesian to Geodetic Coordinates

As far as I understand the literature there are several ways to convert a set of geoecentric cartesian coordinates to geodetic coordinates Bowring, 1976 Borkowski, 1989 Lin & Wang, 1995 Toms, ...
2
votes
1answer
531 views

How to speed up this simple MySQL points in the box query

MySQL doesn't have nearest neighbor search so. So I try to come up with a "distance" that's reasonable so the number of returned query is around 20-200. That way innodb doesn't have to compute ...
3
votes
3answers
2k views

How to define ITRF 92 and ITRF 2008 using Proj4 parameters in QGIS?

I know how to define a CRS, but this particular one is giving me a headache. I was unable to find the EPSG code at spatial reference. The main reason for asking this is that raster and vector data ...
1
vote
0answers
391 views

Importing GPS coordinates correctly

I am importing a gsx set of waypoints with lat/lon taken in degrees, minutes, and thousandths of a minute. When they are added to my project, the waypoints are not showing up correctly - the ...
0
votes
1answer
208 views

How to find embedded Coordinate Reference system in a Layer

I want to find CRS in an added shape file. Ex. In Arc GIS if we go to Layer Properties and Source we can find embedded CRS to a layer. How to find in QGIS, embedded CRS ia a layer/ Shape file??? I ...
2
votes
5answers
676 views

Is there a way to erase GeoTIFF header?

I've got some GeoTIFF files that have wrong bounding box extent and wrong CRS associated to. Fortunately I know the right CRS, but even associating it to the files (I've tried both with QGIS and ...
2
votes
3answers
241 views

coordinate definitions from nyc.gov open data SpatialLocation field

The NYC Open Data website has a dataset of street events. The last column is called SpatialLocation, and is defined as a text field. An example is below. It is clearly two points on a physical map. ...
5
votes
2answers
2k views

What is the SRID of census.gov shapfiles?

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 ...
4
votes
2answers
471 views

How to represent an imaginary flat world in QGIS without using a round-world CRS

Like one or two other users, I'm interested in using QGIS to map an imaginary flat world. A previous answer suggested simply refraining from defining a CRS for such a world, but I cannot seem to make ...
1
vote
1answer
455 views

How does ESRI ArcGIS 10 recognize a WMS CRS?

I'm working on a WMS service with Mars data. Currently the GetCapabilities shows <SRS>EPSG:4326</SRS>. I assume ESRI ArcGIS 10 reads this and therefore the WMS has GCS_WGS_1984 as a ...
0
votes
1answer
193 views

coordinate projection

I'v got a detail map for an event as PDF an made an openlayers slippy map with Maptiler. I now need to place markers at the position of gps/gsm-trackers, which store their coordinate on a server. The ...
8
votes
1answer
249 views

Reprojection - Learning the ins and outs

I would like to expand my knowledge coordinate systems, projections and reprojecting data, with a view of writing a reprojection engine. Could you provide me with some resources (books, websites, ...
0
votes
1answer
192 views

Check multiple feature classes have same spatial reference

As the title says I've several feature classes. I want to check whether they have same spatial reference using arcpy
2
votes
2answers
429 views

How do I set custom spatial reference/coordinate sys to my shapefile

I have a python code which converts JSON text file to a shapefile. I have to set coordinate system to this shapefile created. I do not want to access the .prj file from my computer as this code will ...
1
vote
0answers
237 views

how to correct the coordinate of points [closed]

I have some a layer which contains some points. The coordinate of the points should be GPS points. However, the coordinate of these points are not correct. What should I do? I am using QGIS. If I ...
2
votes
1answer
427 views

How to create aux.xml file?

after starting to use MOBAC to create offline background maps I found the aux.xml files very useful as QGIS automatically sets the CRS so this would be very useful for my colleagues with smaller GIS ...
7
votes
3answers
4k views

Geodetic Coordinates And Latitude, Longitude

Would it right to say that geodetic coordinates (phi & lambda) are the same as latitude & longitude?
1
vote
1answer
955 views

Generating Map Tiles for MGRS Grid Graticule

I'm possibly a bit out of my league here, but ready to get my hands dirty. I want to generate map tiles for a MGRS grid graticule similar to http://tiles.mapbox.com/mapbox/map/afghanistan-mgrs. I ...
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vote
1answer
2k views

distanceTo is giving wrong result in OpenLayers?

Hi i am using distanceTo from OpenLayers to calculate the distance between two locations these are map details Geographic = new OpenLayers.Projection("EPSG:4326"); Mercator = new ...
5
votes
1answer
1k views

MGRS in OpenLayers

I am trying to view the Military Grid Reference System coordinates in Openlayers through the MousePosition control. Is there an easy way to accomplish this just through Javascript? I am looking at the ...
2
votes
2answers
969 views

Convert RT90 into WGS84

Goal: Gain WGS84 decimal to locate some cities in Google Map. Problem: I don't know how to convert the value of the RT90 coordinate system into WGS84 in SQL Server.
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1answer
244 views

Coordinate systems

Does the Coordinate system of a data frame in ArcMap have to match the coordinate system of at least one of the layers in the table of contents? I have found that if defined it will take on the ...
2
votes
0answers
100 views

When using OpenLayers plugins maps, can I have Longitude/Lattitude labelled on my grid when using the Map composer in QGIS?

Using OpenLayers plugins maps, can I have Longitude/Latitude labelled on my grid when using the Map composer in QGIS?