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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3
votes
1answer
64 views

How can I carry out a reliable coordinate transformation for point data?

I have ArcGIS 10.0 with ArcGIS Server (AGS) 10.0. Due to a known bug in the AGS geometry service we cannot carry out coordinate transformations with AGS 10.0. Our Internet client therefore does not ...
1
vote
2answers
196 views

Why does Transverse Mercator projection have scale factor?

Why does the Transverse Mercator projection have a scale factor in ArcGIS and the standard Mercator projection not? In other words what is the difference between these two projections beside being a ...
1
vote
0answers
65 views

LLA vs ECEF--which to choose?

I will be providing points in 3D to an external source via XML. One coworker suggests Lat/Long/Alt and another suggests ECEF. We can do either without much trouble. We have an existing product that ...
0
votes
1answer
65 views

How to reproject Network Dataset from GCS_WGS_1984 to Web Mercator?

I need to know how to change the coordinate system of my feature dataset with its network dataset from GCS_WGS_1984 to Web Mercator. Once I know how to do this, I would like to make a tool in Python ...
1
vote
1answer
344 views

Eastings/Northings OSGB36 Grid origin

Using this site, we can see that the (approximate) centre of Southampton, UK has OSGB coordinates of 441847,112279. However, looking at the UK grid, where each large square is (500 km)2, then these ...
0
votes
1answer
124 views

Get list of CRS in QGIS by python?

It is possible to get list/dictionary of "Recently used coordinate reference system" from QGIS by python? Or get list of all "Coordinate reference systems of the world" also from QGIS by python.
2
votes
1answer
91 views

How do I set the projection and coordinate system for a TIFF file?

I have a topographic map of California (obtained from CAL-Atlas) as a TIFF file. I tried importing it into QGis, but it displays the map using a pixel based coordinate system rather than ...
2
votes
2answers
291 views

Is GeoServer getting coordinate output in GeoJSON WFS wrong?

When I do a WFS request to GeoServer and specify the SRS like this: http://myserver.com/geoserver/wfs? service=wfs& version=2.0.0& request=GetFeature& ...
0
votes
0answers
27 views

QGIS layer only displays when I uncheck on-the-fly transformation

I have a layer that covers the stats of Indiana that has the following Layer SRS: +proj=utm +zone=16 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs It will not display unless I uncheck the ...
4
votes
1answer
130 views

What projection system for the entire world should I use to calculate distances ArcGis?

I've got two point shapefiles (A and B) that represent features all over the world, and I'm using Near (Analysis Tools-Proximity). I'm trying to calculate the distances between the points in layer A ...
1
vote
0answers
75 views

Intersection between a ray from lat, lon, alt, with pan, tilt and earth's surface

I have a problem that consists of finding the intersection point between a ray from a given lat, lon, alt, that is looking to a given pan and tilt angles and the earth's surface. I need the lat, lon ...
1
vote
1answer
136 views

In Ogr2OGR: what is SRS?

I am trying to understand this command: ogr2ogr -f "MapInfo File" original.tab wgs84.shp -s_srs EPSG:27700 -t_srs EPSG:4326 I don't understand the s_srs and t_srs paramaters. The help file says ...
1
vote
1answer
70 views

QGIS with CH1903/LV03 and WGS84 layers

I have a few CH1903/LV03 layers (lake, river and the country border of Switzerland) and a layer in WGS84 (two points of two cities, Vaduz and Bregenz). On-the-fly-transformation is activated but ...
1
vote
1answer
82 views

How can I use the proj string in java code?

I want to do projection from UTM/oblique mercator CRS to WGS84. And I know the solution to use a proj.4 string in commandline like+proj=omerc +lat_0=51.4 +lonc=7 +alpha=-10 +k=1 +x_0=0 +y_0=0 +gamma=0 ...
8
votes
1answer
179 views

Using customized Coordinate System for Archaeological site data

I don't know so much about coordinate systems... In my office we use to deal with spatial data coming from archaeological sites. Each site has its own x-y-z coordinate system (GCS). Three simple ...
0
votes
1answer
324 views

Convert long/lat to indian grid system

how to convert lat/long coordinates to Indian Grid system? I've googled for a couple of days but didnt find the exact algorithm for this. and i got a link Indian Grid System. but i didnt get a picture ...
0
votes
1answer
68 views

Changing CRS for basemap from OpenLayers plugin

Relatively new to QGIS here and I haven't been able to find this question answered yet. I'm working on plotting data from NYC (Queens, specifically) and I would like to overlay my heatmap on a basemap ...
7
votes
1answer
218 views

Can I just swap out a .prj file to reproject a shape file?

I'm an experienced software developer -- but a GIS noob. I have a shape file that I am trying to turn into a SVG map with Kartograph. When I try to run Kartograph I get this error: ERROR 6: No ...
2
votes
1answer
42 views

App using latitude and longitude, should decimal degrees be a separate selection from metric?

So silly question to some I suspect. I am coding a mobile app that displays coordinates in parts of the interface. We currently have an option to toggle between Imperial and Metric. But I am unsure if ...
0
votes
0answers
39 views

recalculate latitude and longitude from a pixel in a cropped map

i want to recalculate a geographic coordinate from a pixel in a map. For this i have the size and the coordinates from the map to convert a coordinate to a pixel is use the algorithm, you find at ...
3
votes
3answers
155 views

How to read coordinates with variable Gauß-Krüger zone (meridian) in QGIS?

Is there a sensible way to visualize coordinates like this as point layer in QGIS? X values starting with 2 are EPSG 31466, 3 is 31467 and 4 is 31468. I didn't try, but i think the same problem will ...
1
vote
3answers
105 views

How ensure data put into PostGIS gets proper CRS attached?

I recently had an intractable problem that we finally traced back to the fact that some points in a PostGIS table had a CRS associated with them and others did not. This resulted in some points being ...
2
votes
1answer
371 views

What is the process to calculate Helmert parameters?

I have some double points (the same points in 2 different datums). I'd like to calculate the Helmert parameters but I don't understand how. NOTE: I don't need software. I need an algorithm in order ...
3
votes
2answers
506 views

Where is list of Geographic Transformations in ArcGIS, and their areas of applicability?

I have some data in Provisional South American Datum 1956, and I need to project it to Web Mercator with WGS84 as the datum. When I use the project tool in ArcGIS desktop, it requires a Geographic ...
0
votes
1answer
54 views

What is the CRS for France

Has anyone any idea what the CRS is for France? I am new to QGIS (moving over from using Arcgis) and trying to find out basics. I have found a huge list beginning NTF (Paris) but wonder which one to ...
0
votes
1answer
44 views

Unable to expand projected co-ordinate system folder in ArcMap 10.1

On trying to re-project any raster from GCS to any PCS, in the "Spatial Reference Properties" window, my "Projected Co-ordinate Systems" folder is not expanding. Where as the GSC folder is expanding. ...
2
votes
3answers
191 views

What are the differences between 81989 and 27700 CRS for the British National Grid?

We are using applying Oracle Spatial to run point in polygon queries in Great Britain using Ordnance Survey MasterMap and point data. MasterMap is on British National Grid (BNG) and has the ...
1
vote
1answer
44 views

How to derive GetFeature URL from capabilities document?

Given this capabilities definition how can I compose a GetFeature request that downloads the actual geodata? I came up with the following URL refering to WFS 2.0.0: ...
2
votes
2answers
91 views

How do I set a CRS when it isn't listed in QGIS? (Mac, not PC)

I want to work with a shapefile that is in a Coordinate System that I can't locate in QGIS for Mac. When I load this shapefile data, it shows up fine, on-the-fly has generated the CRS data most likely ...
2
votes
1answer
125 views

Open Layers and OSGB 1936 (CRS 27700)

I've been working with loads of shapefiles projected according to OSGB 1936 (CRS 27700). THe project CRS is set to 27700 and "On the fly reprojection" to 27700 is set (I keep this as a default as I ...
4
votes
2answers
84 views

Why is it not advisable to perform spatial analysis on layers with source datasets having same datum but different projections?

I have read that it is not advisable to perform spatial analysis on two layers with source datasets having the same datum but different projections loaded in ArcMap. Since the second layer should ...
1
vote
1answer
30 views

Capturing GPS coordinates on the ground in Boliva?

Assuming no cellular or internet connection, what is the best way to capture GPS coordinates on the ground in Boliva? Preferably a free approach. For example, are their any android apps that can do ...
0
votes
1answer
73 views

How to reproject from Clarke_1880_RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA?

I am unable to reproject Marseille shapefiles from Clarke 1880 RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA. I know that Clarke is a geographic coordinate system and it has no datum. I have tried ...
1
vote
1answer
305 views

Pseudo-Mercator projection with Decimal Degrees?

Hope this isn't a duplicate, did some searching but none seemed quite the same. Projection I want: WGS84/Pseudo-mercator. Selected. Looks Great. Canvas units I want: Decimal Degress. Selected. ...
1
vote
1answer
485 views

Trasformation from ECEF to ENU

I am trying to transform a local vector rECEF from ECEF coordinate system to ENU coordinate system (rENU) where ECEF = earth-centered earth-fixed coordinate system ENU = East, North, Up coordinates, ...
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 ...
4
votes
2answers
859 views

What formula is used for distance between 2 points in Google Maps?

What formula is used by Google Maps for calculating the shortest distance between 2 points (having their Lat, Lng coordinates)? Is it purely based on Haversine? Or is it something different? Is there ...
1
vote
2answers
304 views

Openlayers Plugin, Project CRS and Grids in Composer

Apologies in advance for the potential for this to be a duplicate question, I've had a good look, and I can't see a solution thatI understand well enough to help me. I have my project CRS set to a ...
5
votes
2answers
783 views

Describing a coordinate system in arcpy

I have a python script in ArcGIS 10.1 which takes in a few inputs from the user. One of the inputs is a coordinate system. I would like to test whether the coordinate system the user chose was ...
1
vote
3answers
687 views

Formula/ calculation for ESRI map coordinate conversion (meter to decimal degrees)

I'm new to ESRI mapping. I have a set of points in ESRI, with x, y, z coordinates, which I believe is in meters. I am now writing an Android program, and I do not want to depend on ESRI, thus I would ...
2
votes
3answers
319 views

How to calculate Polyline length in kilometres without changing projection from WGS84 (using ArcObjects)?

I have Road (polyline) feature class and I wish to find those roads whose length are greater than 500 kilometre. The feature class projection is in GCS_WGS_1984 and I do not want to change the ...
0
votes
2answers
164 views

How can I find the SRID from the WKT out of a GRIB file?

I have a grib2 file which I'm trying to import into PostGIS 2.0 Raster and process. Trouble is, I can't figure out what the SRID is supposed to be, or one close enough for government work. Running ...
1
vote
2answers
64 views

Create Geographic Reference for X,Y Coordinates [closed]

I have a set of x,y data that do not have any sort of geographic reference. I have lat/longs (WGS 84) for a small set of those points. How can I calculate lat/long for the remaining points so I can ...
3
votes
2answers
116 views

Convert data to another Coordinate Reference System

Assuming I've a point like this : POINT (751318 9760879) This point is in EPSG:27700 coordinate reference system. How do I convert the point to display in a map with EPSG3857 coordinate ...
6
votes
1answer
145 views

How do I change an existing srs in QGis?

I am showing postgis data with srid 28992 (Amersfoort / RD New). But when I plot the geospatial data on a map (with openlayers plugin), the data is shown a hunderd meters off because the datum shift ...
0
votes
2answers
79 views

How to choose spatial reference for GPS data?

We received GPs data from the vendor. I want using ArcGIS software to create XY event table and create a point feature class. What the spatial reference would be for the GPs data? Is it something I ...
-1
votes
1answer
173 views

How to project geographic coordinates to cartesian with the least possible error? [closed]

I need to convert geographic coordinates (in decimal degrees) to cartesian with the least possible error? I searched a lot on the internet but it seems that the conversion is not exact. Could you ...
16
votes
5answers
18k views

Get list of coordinates for points in a layer?

I've got a layer in QGIS that is comprised of points. Its attribute table doesn't have (show) the corresponding x and y coordinates for each point. Is there a way for me to extract a list of ...
1
vote
0answers
59 views

How does Arbitrary Coordinate System in QGIS work?

I have got the drill hole data, which needs to be geo-referenced based on non-earth coordinates system (with no datum, ellipsoid information defining through Custom CRS). Could any one explained me ...
1
vote
1answer
175 views

Save as Image geotiff from OpenLayers plugin [closed]

Now i'm working with the new version of Qgis 2.0 but I have a problem with the OpenLayers plugin. I take a geotiff screenshot of an area in EPSG:3857 and then I load the image.I'd check out the CRS of ...