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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59 views

Error getting spatial reference as string in arcpy

I am trying to get the string associated with a spatial reference to print into an xml using arcpy and xml.cElementTree. Using the snippet: ... spatial_ref = arcpy.GetParameterAsText(3) ... Prj = ...
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1answer
17 views

QGis polygon to points different CRS problems

I'm trying to join the values from polygons onto a grid of points. I had this problem solved here by @Underdark , however a few layers weren't working. It seemed they were all British National Grid ...
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2answers
380 views

What does coordinate system WG 21° mean?

I have a land survey document for a piece of land, it contains absolute coordinates that I would like to locate on google maps, but I don't know how to correctly interpret the data. What does the ...
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1answer
58 views

Gdalinfo and QuantumGIS does not recognize Spatial Reference even though Python does

I apply the following Spatial Reference to a file: spatialRef = osr.SpatialReference() spatialRef.ImportFromEPSG(3411) outraster.SetProjection(spatialRef.ExportToWkt() ) geotransform = ...
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5answers
274 views

Is latitude / longitude a universal coordinate system?

I hear people complain: my biggest gripe with google spatial apis is that they hide the fact that latitude/longitude is not a universal coord system My question is Is latitude / longitude a ...
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1answer
53 views

datum conversion with GDAL

I run gdaltransform like so: gdaltransform -s_srs nad27 -t_srs wgs84 -104.5 39.5 -104.5 39.5 0 gdaltransform -s_srs wgs84 -t_srs nad83 -104.5 39.5 -104.5 39.5 0 gdaltransform -s_srs nad27 ...
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1answer
42 views

Problems with french coordinate systems (i.e. Lambert Zone I, EPSG 27571)

I'm working on a coordinate library implementation and I seem to be stuck with the French Lambert coordinate systems. I'm using this page as a reference (can anybody confirm the results there are ...
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2answers
51 views

Calculate length of line across zones with at least m accuracy

I have created lines between multiple points that are across MGA 54 and 55S (EPSG 28355). I am trying to calculate the distance between points but different methods give different answers (~1km ...
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2answers
121 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 ...
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1answer
90 views

Calculate distance between two Coordinates to use in Variogram calculations in ordinary kriging

i need to calculate distance between two stations in a map in order to calculate empirical variogram in ordinary kriging to interpolate temperature data . calculating distance in kriging done using ...
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0answers
50 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 ...
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2answers
43 views

Define a projection for one point

I'm new to ArcGIS and am using ArcMap 10.1. I wanted to find the distance from a point (lat 36N long 12E) to all the polygons in my shape file. People on this forum helped me out and said that I ...
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1answer
175 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 ...
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1answer
55 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.
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1answer
43 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 ...
2
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1answer
60 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 ...
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1answer
78 views

How to identify township range and section from longitude and latitude

I have several hundred coordinates in an Excel file. I would like to identify the township range and section they are located--what is the easiest way to do this? I have you QGIS and basic GIS skills ...
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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 ...
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1answer
105 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 ...
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1answer
102 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 ...
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0answers
50 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 ...
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0answers
50 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 ...
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1answer
48 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 ...
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1answer
53 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 ...
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1answer
128 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 ...
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1answer
48 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
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1answer
174 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 ...
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0answers
27 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
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1answer
35 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 ...
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3answers
65 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
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3answers
116 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 ...
2
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1answer
142 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 ...
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1answer
110 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
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1answer
43 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
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1answer
42 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
88 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 ...
7
votes
1answer
117 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 ...
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1answer
28 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
63 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
91 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 ...
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1answer
29 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
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1answer
56 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
74 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 ...
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1answer
154 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. ...
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1answer
57 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 ...
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1answer
158 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
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2answers
476 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
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3answers
199 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 ...
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2answers
54 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
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1answer
100 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 ...