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.

learn more… | top users | synonyms (3)

1
vote
1answer
1k 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
231 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.
3
votes
1answer
140 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
0answers
182 views

Kartograph - “projection not named”

The Kartograph package looks very promising, so I have been trying play around with it. As it turns out, I have been able to get the most basic map to work (the "world.json" example), but I could not ...
2
votes
1answer
227 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 ...
0
votes
0answers
39 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
180 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
1answer
219 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
411 views

DotSpatial.Projections Vs. ProjNET4GeoAPI

DEAR PEOPLE FROM THE FUTURE: Here's what we've figured out so far… I have been facing the issue of transform coordinates from a custom spatial reference to a well known spatial reference (let's say ...
1
vote
0answers
242 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
178 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
245 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 ...
1
vote
1answer
2k views

Converting longitude and latitude coordinates 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 ...
0
votes
1answer
110 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
312 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 ...
1
vote
0answers
115 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 ...
2
votes
1answer
70 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 ...
1
vote
3answers
293 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 ...
3
votes
3answers
252 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 ...
3
votes
2answers
2k 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 ...
2
votes
1answer
516 views

Leaflet setView with non lat/long CRS

Is it possible to use setView when using an alternative CRS? var map = L.map('map',{crs: L.CRS.EPSG26915}).setView([4970081,477018], 13); // Returns: Uncaught TypeError: Cannot call method ...
0
votes
1answer
72 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
55 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
4answers
250 views

Get “approximate” lat/long coordinate for UTM grid zone

I have data assigned with a UTM grid zone designators, such as 10S for example. Now I need an approximate latitude/longitude pair, preferably the center point of the given grid zone. Can you give me ...
2
votes
3answers
585 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 ...
9
votes
1answer
618 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 ...
1
vote
1answer
120 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
156 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
289 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 ...
1
vote
1answer
38 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
122 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 ...
4
votes
2answers
120 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
985 views

Using a Select By Location in Python and Calculating a field based on what State Plane a point falls in

Here's what I have so far. Do I need to make another feature layer based on the selection? import arcpy arcpy.MakeFeatureLayer_management(r"PATH TO THE POINT", "point_lyr") ...
1
vote
1answer
1k 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
202 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
2k 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, ...
4
votes
2answers
2k 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 ...
2
votes
3answers
794 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 ...
1
vote
2answers
84 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 ...
6
votes
1answer
343 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 ...
3
votes
2answers
172 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 ...
0
votes
2answers
95 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
402 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 ...
1
vote
0answers
91 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 ...
2
votes
2answers
626 views

QGIS DXF file projection match

I need to use this file on a map but I am not able to match the projection with the others I have, primarily data downloaded from OSM (city of Boston). I read many articles, I have repeatedly tried to ...
2
votes
1answer
71 views

WGS84 CRS without elipsoid

What's the difference between using CRS defined as +proj=longlat +datum=WGS84 +no_defs and a CRS defined as +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs Will using one or the other pse any ...
2
votes
1answer
1k views

ArcGIS giving measured distances and the scalebar incorrectly

I am currently using ArcGIS 10.1 and am struggling to be able to measure distance or set a scale bar correctly. Its currently giving me absurd results orders of magnitudes to small (0.5m etc). All my ...
2
votes
0answers
545 views

Which of EGM96 geoid or WGS84 ellipsoid fits the earth better?

ImageCredit Question If we separately add up |H| and |h| over the earth surface, which of the sums come out smaller? Background There is a phrase in the tag description of "ellipsoid" that says ...
2
votes
1answer
114 views

What do different realizations of the same datum have in common?

Firstly, am I correct in assuming that the process of determining the shape and the size of the spheroid is independent from the process of determining the origin and the orientation? For example, ...
3
votes
2answers
3k views

How to convert 6 & 7 digit coordinates to degrees latitude & longitude

I'm a bit new to the whole GIS world, and though I am making great headway drawing polygons and such in Bing Maps, I am currently stuck. In our SQL spatial data, I came across MULTIPOLYGON data, where ...