The process of translating a map or spatial data from one geographic projection to another

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24
votes
3answers
23k views

Layers with same coordinate system should align/overlap but do not?

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
20
votes
1answer
2k views

What is most accurate coordinate system for calculating areas of polygons?

I have multiple polygons, all located offshore around the UK. I am trying to calculate the areas of these polygons in square kilometres, without splitting them by UTM zone. Is it possible to do this ...
5
votes
1answer
841 views

Raster incorrectly reprojected to OSGB(27700)

Ubuntu 12.04, QGIS 1.8.0, GDAL/OGR 1.7.3, GEOS 3.2.2 Open a Spatialite db with OS Mastermap poly layer (EPSG:27700); Add OpenLayers Plugin (1.0) from QGIS offical repository; Add a Google Satellite ...
13
votes
2answers
12k views

How to reproject a vector layer in QGIS?

I have some shape file which is in UTM. I wanted them to convert to Decimal Degrees in QGIS. Thanks.
14
votes
2answers
10k views

What is the difference between EPSG:900913 and EPSG:3857?

I'm using the QGIS google layers plugin to digitize a parcel as a shapefile. Later I want to import it to PostGIS. I know that google maps use a special 'google mercator' projection. What is the ...
8
votes
1answer
3k views

How to reproject a raster file in QGIS with datum transformation?

I want to reproject a tiff raster file from projection A (ETRS89/UTM Zone 32) to projection B (DHDN/Gauss-Kruger zone 2). The two projections have a different datum so I have to use a datum ...
5
votes
3answers
3k views

How to use ArcObjects to choose GeoTransformation?

I’m currently building a Desktop add-in tool with ArcObjects that: Asks a user to select a feature class Reprojects the feature class to Web Mercator Executes some geoprocessing The initial ...
16
votes
5answers
11k views

Map projection in OpenLayers

I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows: map = new OpenLayers.Map('map', { ...
46
votes
8answers
2k views

One dimensional map of the world?

Bit of a strange question but hope this is OK to ask here. Has anyone heard of a '1-dimensional' projection of the world map - that is mapping all the points on the globe to a single line? I was ...
18
votes
3answers
6k views

How to reproject all geometries in a PostGIS table?

I created a spatial table with SRID:4326. Now I want to change total projection to SRID:32644 into a new table. The old table should remain unchanged.
6
votes
3answers
8k views

Converting X,Y coordinates to lat/long using pyproj and Proj.4 returns the wrong coordinates

I'm writing a python script that reads multiple XML files containing x and y coordinates and combines them all into a single csv file. Latitude and Longitude are required fields in the csv, but I am ...
9
votes
2answers
13k views

How to enable projection transformation in QGIS

My QGIS project has two layers, one layer is retrieved by Google layer plugin which fetches the static Google map image whose CRS is +proj=merc +lon_0=0 +lat_ts=0 +x_0=0 +y_0=0 +a=6378137 +b=6378137 ...
2
votes
1answer
2k views

Convert area from square meters to degrees globally

I have a global raster file with 3600x1800 pixels. I don't have any information about the projection used. The raster contains one band with a quantity with the unit "per square meter". How can I ...
10
votes
10answers
8k views

Batch convert lat longs to UTM?

I've got a .csv file that contains a long list of latitude and longitude points. Is there an efficient way to batch convert the list into a projected UTM coordinate system? Thanks.
2
votes
0answers
936 views

OSGB36 to WGS84 reprojection 'error'

First off, I am a recent convert to QGIS and am greatly impressed with its ease of use and speed compared with the ESRI products with which I am more familiar - my congratulations and thanks to its ...
13
votes
1answer
7k views

Projecting sp objects in R

I have a number of shapefiles in different CRSs (mostly WGS84 lat/lon) that I'd like to transform into a common projectly (likely Albers Equal Area Conic, but I may ask for help on choosing in another ...
10
votes
2answers
1k views

How can I improve my Georeferencing results?

Background This is my second question related to georeferencing naked raster maps in order to re-visualize them on different coordinate systems and in conjunction with other data layers. The previous ...
14
votes
5answers
2k views

Does Re-Projecting ShapeFile only update content of *.prj file?

if i wish to change the projection of some shapefiles from .. lets say NAD83 (4269) to WGS84 (4326) ... and by using some 3rd party app .... does this mean the .prj file is only updated .. and not the ...
3
votes
1answer
6k views

Transforming from SRID 900913 to 4326 with PostGis

I have two Postgres tables with different SRIDs: 4326 and 900913. I want to convert the latter to 4326. I first changed the SRID using: Select UpdateGeometrySRID('table', 'geomcolumn', 4326). I ...
4
votes
2answers
641 views

What's the best projection for rasterization of random latitude and longitude data in the northern Atlantic?

I have a dataset in the WGS84 geographic coordinate system that I would like to interpolate along a grid using Python. It appears gdal_grid is not available through the Python bindings, so I plan to ...
2
votes
2answers
223 views

Problem with reprojecting raster from MGI 6 to WGS

When I reproject a raster from Mgi 6 to WGS 84 using Warp in Quantum gis it makes mistake ( about 380m). Is there any way to avoid this?
5
votes
5answers
2k views

Can I copy an entire geodatabase with relationship classes and domains and reproject all feature classes from wgs84 to state plane?

I have an SDE geodatabase with several feature classes, tables, relationship classes, and domains. All the feature classes are currently in WGS84 coordinate system. I need an exact copy of the ...
5
votes
2answers
5k views

Convert x, y position in georeferenced image (with world file) to longitude, latitude?

What steps do I need to do in order to calculate longitude and latitude for a specific pixel in a georeferenced image? For example this image ...
4
votes
2answers
314 views

How to Intersect a layer with custom CRS with NED data?

I am trying to create a map with a layer of county tax assessor property parcels plus NED elevation data. The projection of the tax assessor layer is a weirdo -- looks like user-created by the ...
4
votes
3answers
2k views

How can I find out how to convert this point to lat lon?

I have received a shapefile with measurement points to be analyzed, but no matter how I try, I can't find how to convert to lat lon. I suppose it would be good to know the projection but when I look ...
3
votes
1answer
893 views

Re-project raster image from Mercator to Equirectangular

I have a raster image of the world map in Mercator projection, square 1:1 format. I want transform the image into an Equirectangular projection accurately. I assumed from my research that GDAL would ...
3
votes
1answer
1k views

C# Library for converting Shapefile Projection

Is there any C# library which can take a shapefile as an input with projection information defined (e.g, EPSG 3011) and return a new shapefile with user specified projection (e.g, EPSG 4326) ?
2
votes
3answers
655 views

Can I use Openlayers Plugin with a different Datum/Projection?

There is probably already a post for my problem, but after long searching, I could not find a solution for my issue. I am working with QGIS und I am using the following projection/datum: MGI / ...
2
votes
1answer
485 views

How to re-project the EASE (Equal Area Scalable Earth) grid with a ~25 km cylindrical projection to WGS84 0.25 degree?

I have nc files. from the metadata ,the projection is cylindrical and the resolution is 25 km: indrical NC_GLOBAL#ease_resolution=25 ...
1
vote
2answers
69 views

How can I make the UTMs of different datasets uniform?

I have wind datasets for every U.S. state and want to merge them. I found out that these datasets use different UTMs. So I want to make the UTMs uniform. How can I do that? This can not simply be done ...
1
vote
1answer
125 views

How to match a raster NetCDF data with a vector layer in QGIS?

When I load a raster layer with humidity data from NOAA database (for instance rhum.2m.2014.nc at ftp://ftp.cdc.noaa.gov/Datasets/NARR/Dailies/monolevel/) I am not able to match it with a simple map ...
1
vote
1answer
197 views

How to Buffer data in a Geographic coordinate system?

I am having an issue with buffer. My data is in Geographic coordinate system. I am trying to do a buffer of 600m and i am finding different results for each case, have tried thse so far: Map in web ...
1
vote
3answers
4k views

Convert Lambert Conformal Conic to WGS84

I am trying to convert my "Lambert Conformal Conic map with 2 standard parallels" to the basic/standard WGS84 projection that Google Maps use. I have 30 of these maps which I need to convert. They ...
0
votes
1answer
399 views

Reproject GeoJSON from EPSG:3857 to EPSG:4326

I am using this reproject tool to convert a GeoJSON point from EPSG:3857 to EPSG:4326. My command fails. What am I doing wrong? $ echo ...
0
votes
1answer
735 views

Re-projection in Geoserver

I have published a layer on Geoserver by cascading a remote WMS. i have successfully got all the layers from remote wms and publish one of those layers. But I want to re-project the layer from its ...
3
votes
2answers
4k views

Choosing the correct value for proj4string for shape file reading in R “MapTools”

I am having a shape file of polygons and another CSV file which contains a list of points as (Lat, Lng) pairs.. I want to check for each (lat, lng) pair from the CSV file which polygon does it fall ...
9
votes
2answers
3k views

Derive WGS84 Longitude & Latitude from British Northings & Eastings

I'm looking for a fairly simple way to append columns with WGS84 longitude and latitude to a table containing northings and eastings. The source data is Ordnance Survey's CodePoint Open, which I is ...
4
votes
3answers
6k views

Using the Proj4js library to convert from Google Maps to projected values

I'm using the proj4s javascript library (based on advice from this question I asked previously) to convert lat/long values on my webpage. This page receives the lat/long values from google maps and ...
4
votes
1answer
93 views

Why are raster z-values changed when reprojecting?

I have raster data with height values (z). When I try to reproject/warp the raster to Gauss Kruger 3, the z-values are changing (several meters). (The data is already GK3, but I have to reproject ...
4
votes
2answers
351 views

How to register shapefiles to an image?

I'm generating images from various sources and the projections are not necessarily known ahead of time. The images are subject to interpolation and other alterations while being rendered, but I can ...
4
votes
3answers
8k views

How to convert MGRS to Lat/Long or UTM?

Can anyone please guide me on converting Military Grid Reference System (MGRS) to lat/long or UTM. Any help is greatly appreciated. Rahul
3
votes
3answers
16k views

How to convert x y coordinates to longitude latitude using QuantumGIS?

I'm working with this downloadable shapefile that has X Y coordinates. They are akin to '3672187.92698000, 534175.72095400'. I would like to convert them to longitude latitude so they are more like ...
3
votes
2answers
3k views

Converting NZMG (or NZTM) to latitude / longitude for use with R map library

I am a statistician with no background in GIS so apologies for the newbie question. We routinely use R for a range of statistical and graphic analysis and are interested in using its map library to ...
3
votes
1answer
2k views

How to write a script that re-projects vector datasets in a folder?

This is probably a novice question, but I am a novice with python. I am trying to write a script that re-projects vector datasets in a folder. However there are rules in which to do this. They are: ...
9
votes
6answers
7k views

ArcGIS/ArcPy Python, how to get latitude and longitude of a projected point?

I have a point feature in a feature class that is being accessed by ArcPy. The point is projected but I need to find an efficient means to get the unprojected latitude and longitude for this point. ...
6
votes
2answers
6k views

Basic proj4 conversion UTM grid -> longlat and back

I'm a GIS novice, and am struggling to understand how to drive proj4 to accomplish what seems like a simple thing. I've googled for a couple of days, but everything I find seems to presuppose quite ...
5
votes
2answers
1k views

Does anyone know the proj4 Coordinte Reference System command line for Rectangular Polyconic Gores?

I am a GIS beginner using QGIS 1.8.0 I am trying to transform a world map from the standard WGS84 Coordinate Projection System to a set of rectangular polyconic gores, with a gore count of 12. ...
5
votes
1answer
630 views

Custom Geographic Transformation on QGIS

Is there a way to create a custom geographic transformation with specifics parameters in QGIS like in ArcGIS? Okay, I want to tranform SAD69 system into WGS84. Well, I'm in doubt because in ArcGIS ...
5
votes
1answer
1k views

MGRS in OpenLayers

I am trying to view the Military Grid Reference System coordinates in Openlayers through the MousePosition control. Is there an easy way to accomplish this just through Javascript? I am looking at the ...
5
votes
4answers
699 views

Given long, lat, x and y, how do I find the projection?

I am using an app called farsite that outputs shapefiles that show how forest fires will grow. I am getting output in coordinates as X and Y values rather than (lon,lat) and am looking for a ...