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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206 views

Why is shapefile layer not visible on WMS layer in QGIS?

In my QGIS project I have added a WMS layer for which the CRS is WGS84 EPSG:4326. Now I want to show my shapefile layer which has the same CRS. QGIS shows the layer separately but does not show with ...
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1answer
38 views

what is the relevance of cosine in determining map resolution? [closed]

"At any latitude and zoom level, you can determine the scale by using the following equation" Map resolution = 156543.04 meters/pixel * cos(latitude) / (2 ^ zoomlevel) is a quote from ...
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0answers
135 views

I had an error in Gdalwarp and i don't know the reason

I was trying to warp a raster using a mask and shift it before clipping but when i exectute the command bellow in Qgis/PyQt using QProcess: gdalwarp -s_srs "+proj=merc +a=6378137 +b=6356752 ...
0
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1answer
169 views

Scaling x,y coordinates in proj4

This question was asked before, but without answer. Let's say we have mercator map with given resolution (for simplicity in centimeters). Now let's get coordinates of (lat,lon) = (50, 15): $ proj ...
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1answer
181 views

Coordinate mix up

I am working on a basic map, pulling coordinates from google earth, converting them to decimal degrees in excel, and then importing them into qgis. I am using qgis 1.8. When converting from degrees, ...
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3answers
812 views

Can someone clear up a lat/long issue? with google maps/arcmap

I know a bit about lat/long, projected and geographic coordinate systems etc, and a bit about geodesy and datums, but I would like someone well informed to help me out. I have a lat-long in ...
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2answers
88 views

Which GEO data format does this data represent

I am parsing GIS data from a ESRI webservice in which I get the data specified as the following in a JSON file "geometryType" : "esriGeometryPoint", "spatialReference" : { "wkid" : 102100 an ...
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0answers
101 views

QGIS convert attribute table to point shape

I have imported an attribute (whith no spatial information) table from MySQL. Fortuantly it has two colums with Longtitude and latitude taken from google maps. Is it posible to use those values to ...
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1answer
239 views

Convert decimal latitude/longitude bounding box to SRID 26910

I have a bounding box specified in decimal latitude/longitude, and need to convert this into a bounding box in the SRID 26910 coordinate system. I've never had to work with different GIS co-ordinate ...
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1answer
270 views

How to support multiple Coordinate systems with ArcGIS Server 10.0 WMS?

I have a serve a number of wms Layers with ArcGIS Server (AGS) with the following coordinate system support - EPSG:25832, EPSG:31467, EPSG:4326 and CRS:84. As far as I can tell, AGS only supports 2 ...
2
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0answers
31 views

changing central meridian in QGIS causes problems [duplicate]

I want to change the central meridian of my world map (WGS84) in QGIS from 0 to -80. The problem is that this distorts the map every time I try it. This is what I do: go to Settings/Custom CRS ...
2
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0answers
43 views

Is it safe to store coordinates on NFC tags always in one CRS and rely on conversion for others

I'm involved in NFC (Near Field Communication) standardization of a record structure for geographic point locations. That will allow to put coordinates on NFC memory tags which can be read with a ...
2
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1answer
107 views

Unknown coordinate system warning when programmatically adding layer

I have another interesting question for you. I have data with unknown coordinate system. When I add this data using a standard tool(File->Add Data) in ArcMap, a warning dialog appears. It looks like: ...
2
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1answer
50 views

File representing extents of coordinates systems and their wkid

I'm looking for a file that represents the major coordinate systems throughout the world, and the extent that they cover. Ideally they'll also have the wkid as an attribute. Something like the ...
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1answer
1k views

QGIS v2. Convert longitude/latitude to UTM projection-Zone 51J - Southern hemisphere [duplicate]

Could somebody please let me know in QGIS version 2.0.1 How do I convert Longitude/latitude default setting to UTM projection. I am bringing in waypoints from a GPS device which is set to the above ...
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2answers
711 views

I get an ERROR 000622 when it checks for arcpy.DefineProjection_management

So the purpose of my code is to create a loop that copies shapefiles from a folder to my folder and change its projection 'GCS_WGS_1984'. Each shapefile starts with the year follow by the month and ...
0
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1answer
126 views

Aligning two layers captured in different coordinate systems

I have two layers, one of points (locations of fruit trees) and one of Atlanta zip codes, in an ArcMap, but the layers are not aligning. The zip codes are in the top right and the fruit points are ...
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2answers
230 views

Add custom CRS - 2.2.0 Valmiera

i've builded a custom proj.4 library, tested it by command line (proj and cs2cs) and with postgres/postgis. All works fine. Now i'm trying to make the same with Qgis 2.2.0. I've replaced the original ...
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1answer
70 views

Why is it important to ensure that the shapefiles have a spatial reference system when created?

Why is it important to ensure that shapefiles have a spatial reference system when created?
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1answer
398 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
55 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 ...
6
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2answers
790 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 ...
1
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1answer
96 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 = ...
2
votes
5answers
519 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
453 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
384 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
145 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
432 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
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1answer
319 views

Haversine formula to calculate distance between real coordinates?

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 using ...
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0answers
77 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
79 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
985 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
201 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
129 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 ...
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0answers
152 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
167 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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0answers
35 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
169 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
192 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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1answer
317 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
190 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
150 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
173 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
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 ...
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1answer
100 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 ...
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1answer
297 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
86 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
58 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
229 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
228 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 ...