Tagged Questions

1
vote
1answer
39 views

How to transform World data from EPSG 4326 to EPSG 3857

I have tryed different opensource tools to transform a world data shapefile from 4326 to 3857 but I always have an error. Im not sure, but is it because of Antartica? I have tryed with GDAL and QGIS ...
1
vote
0answers
53 views

Using gdal to convert from UTM to equidistant lat/lon

I am getting rather confused with converting a UTM gridded dataset into a equidistant/rectangular latlon gridded dataset. Can anybody help me? I have a UTM set with the following projection: ...
11
votes
1answer
103 views

Assign projection to a satellite image

Today I stumbled upon a picture taken from the ISS looking down Europe and it is really beautiful. So, I started thinking I could add more to the picture. Like world borders, cities, road network, ...
0
votes
3answers
264 views

How can I get the proj4 string or EPSG code from a shapefile .prj file?

I have to work with a shapefile defined in an unusual projection, which my GIS software does not know about. How can I get the proj4 definition or the EPSG code for the projection?
2
votes
2answers
117 views

Cartesian world sized projection WKT/EPSG code?

I am after the EPSG code or Well Known Text (WKT) of a projection that puts the centre of the earth a 0,0,0 and each point is a cartesian XYZ distance from that. My existing data is in WGS84 ...
2
votes
1answer
54 views

How to test if two GDAL datasets are in the same projection?

I'm attemping to write a funciton to test if a list of datasets are in the same projection. Naively, I thought I could test the text of WKTs, but that does not work in the following case: ...
0
votes
0answers
98 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 ,here is one file https://echange-fichiers.inra.fr/get?k=LUfqiyO1Dl7az5bihnS. from the metadata ,the projection is cylindrical and the resolution is 25 km: ...
4
votes
2answers
191 views

How do I Capture GDAL projection and create matching output (OGR or GDAL) shape files?

Working in C++, using GDAL and OGR: Depending on what the user has supplied for image input, I need to output point (or other) shape files in the same projection as the input raster images. The ...
2
votes
0answers
83 views

projection discrepancy with gdal (1.9) and proj4

I boiled the problem down to that python example: import sys try: from osgeo import gdal from osgeo import osr except: import gdal import osr if __name__ == '__main__': version_num = ...
3
votes
1answer
180 views

Get the geotransform in Mercator given a pixel size away from the origin

I have a radar image with the following information: The projection is Mercator (Mercator_1SP in GDAL) The projection origin is 0º lat 0º lon At a given geographic coordinates (e.g. lon=10º ...
10
votes
2answers
254 views

How to reproject raster from 0 360 to -180 180 with cutting 180 meridian

I have a geotiff raster image that has a coordinate system with longtitudes from 0 to 360. The horizontal center of the image is 180 longtitude. See image below: I want to transform it to EPSG:4326 ...
4
votes
1answer
138 views

How to convert a png with known bounds from Plate Carree to Mercator with GDAL

I have a png image that shows the region defined by the geo bounds UpperLat, LeftLon, BottomLat, RightLon (in degrees & -ve for West Lon and South Lat) in Plate Carree EPSG:4326. I want to convert ...
9
votes
2answers
1k views

API documentation for Gdal/Ogr with C#

I want to assign projection to shapefile in my web C# application, for this i am using Gdal/OGR/OSR C# bindings and add osr_csharp.dll and ogr_csharp.dll references. But i am facing some difficulty ...
2
votes
1answer
338 views

How to determine area of pixel in meters with GDAL and Python?

I have a raster loaded in Python using GDAL bindings. I'd like to be able to determine the area of a pixel in meters although I'm not confident that the projection is in meters. On this page I see a ...
3
votes
2answers
198 views

What projection is this in GDAL classification

I need to re-project a PNG from a given projection to the Google maps projection. I have a grid of the source projection, looks like a Mercator projection. What is the exact name of this projection in ...
1
vote
1answer
192 views

How to reproject a noaa bsb nautical chart?

I have some nautical charts in .BSB format. GDAL can read bsb and I successfully imported them to qgis. But I can't figure out what is the coordinate system they use. Does anyone has some experience ...
2
votes
1answer
604 views

How to provide transform information to openlayers on Image layer

I would like to include an overlay raster layer into my OpenLayers map. I've pre-transformed the image into the correct projection (EPSG:900913) and saved as a png using the gdal_translate command: ...
4
votes
2answers
530 views

What's a good toolchain to reproject some PNGs in plate carre to UTM?

I have some PNGs produced from Canadian DEM data. They're 1201px by 1201px heightmaps. Each one represents one quarter of a degree latitude and one quarter of a degree longitude. But I want to work ...
5
votes
2answers
2k views

How do I use GDAL to convert from an arbitrary projection/datum into Equirectangular/WGS84?

I've been trying to use GDAL to convert from an arbitrary projection/datum into Equirectangular (aka Plate Caree, aka Equidistant Cylindrical, aka Geographic, aka Lat/Long) with WGS84 datum. All of ...
5
votes
1answer
417 views

What is north-up projection?

How do I know what projection to use for north-up or 0 rotation? I have a gtiff (ND83-nf) that gives me the error when importing to Grass. Should I re-project or recreate the image with the rotation ...
0
votes
3answers
382 views

Need help understanding why gdal projections aren't giving me what I expect?

When using gdaltranslate and gdalwarp I specify the following transfomation (in for GCP's and translate, out for warp) +proj=lcc +lat_1=40.03333333333333 +lat_2=38.73333333333333 +lat_0=38 ...