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.
1
vote
1answer
111 views
Taking a 'custom' map and transforming its x/y co-ordinates to 'real' long/lat co-ordinates?
I was wondering if someone could help me out with a little project I'm working on. I'll try to describe what I'm trying to achieve - if it doesn't make sense, please let me know.
I have in front of ...
2
votes
1answer
123 views
What coordinate system is this?
I just found a dataset of trees in San Francisco, but I'm unable to determine the system used for the coordinates. Here are some samples:
5998894.045593,2119007.035323
...
3
votes
1answer
162 views
Cannot select a feature using ArcObjects because coordinate systems differ
I'm using ArcMap 10 and Bing Maps Road as base map. Then we have our adding which is programmed using C#. What I'm trying to do is to select a feature (A) that intersects another feature (B, from a ...
2
votes
0answers
135 views
Coordinate systems conversion
I have the following task.
This is my sample data.
WGS84 datum (longitude/latitude):
-123.75 36.59788913307022
-118.125 40.97989806962013
Spherical Mercator (meters):
-13775786.985667605 ...
2
votes
1answer
81 views
Library design: Layer coodinates/origin
I am working on a vector map library where you can add plain image and vector layers to a map. The map itself consists of an infinite coordinate system and each layer is a coordinate system of it's ...
1
vote
0answers
59 views
Coordinate system for map downloaded Digimap?
I have download a 1: 25000 map from Digimap. It came as a tif file along with a tfw file. When I try to import the tif file as a raster layer, I get the following message: 'this layer appears to have ...
2
votes
1answer
158 views
How to programmatically determine whether a spatial reference factory code is valid?
I am using the following code segment to create a spatial reference.
spatialReferance = arcpy.SpatialReference()
spatialReferance.factoryCode = spatialReferanceFactoryCode
...
0
votes
0answers
62 views
Coordinates move in sql server insert
When I insert a row in TableA in sql server I use this for the geometry column:
geometry::STPolyFromText('POLYGON((x1,y1,x2,y2,x3,y3,x4,y4,x1,y1))', 3007)
You can find the definition for ...
0
votes
1answer
99 views
If the Earth was flat, what unit of measurement would distances between geographic points be represented as?
A whole lot of abstraction- given two longitude/latitude points given from a GPS, I'm using the Pythagorean distance formula to find the distance between them. What unit of length would the distance ...
0
votes
0answers
91 views
In Geoserver, Using as a Data Store the Web Feature Server option, but I have a serious problem
I’m using as a Data Store the Web Feature Server option, but I have a serious problem, because Geoserver needs to know what Coordinate Reference System of my data. This information is used for ...
3
votes
1answer
316 views
QGIS custom CRS for map of manufacturing shop floor
I'm working on a web app that shows a map of a manufacturing plant's shop floor. I've built it in Inkscape and QGIS, but when I try to load it into Tilemill, I get a CRS error. Specifically, it ...
5
votes
2answers
411 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 ...
1
vote
1answer
162 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 ...
3
votes
4answers
189 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
692 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
380 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
1answer
319 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 ...
3
votes
1answer
253 views
Different coordinate system for map project and scalebar?
Is it possible to specify a coordinate reference system (CRS) for the scalebar that is different to the project CRS?
Example: my project CRS uses geographic coordinates (lat/long), the reason being ...
2
votes
1answer
473 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
843 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:
...
1
vote
3answers
630 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
96 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
470 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
225 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
151 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
23 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
205 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 ...
0
votes
0answers
15 views
QGIS 2 shape 2 different projections [duplicate]
Possible Duplicate:
Why don't different layers overlap in Quantum GIS?
I have a problem with 2 shape coming from different sources.
They represents differents items of Italy (roads and ...
1
vote
0answers
105 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
260 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
votes
1answer
124 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 ...
0
votes
4answers
767 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
...
0
votes
0answers
100 views
Project custom metric coordinates on the EPSG map with GeoServer [closed]
I have an application that displays different items on the custom map. The map has a coordinate system which is basically (X,Y) coordinates in centimeters where top-left corner has coordinates(0,0). ...
3
votes
0answers
50 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, ...
8
votes
2answers
647 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
661 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
140 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 ...
1
vote
1answer
542 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, ...
4
votes
3answers
85 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 ...
1
vote
1answer
101 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. ...
7
votes
1answer
533 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
301 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
696 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
310 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
141 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
4answers
232 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
113 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
538 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
277 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
268 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 ...
