Tagged Questions

0
votes
0answers
13 views

How to set GDAL/cs2cs/proj to use NTv2 grid shift file when using EPSG codes?

I am using the GDAL API for Python for a script that takes only EPSG codes for inputs to specify source and target coordinate systems. While the cs2cs command seems to handle quite well ...
1
vote
2answers
98 views

ESRI State Plane Coordinates as EPSG

I am working with some State Plane projections from Colorado. I have looked them up on spatialreference.org and they are the following: ESRI:102254: NAD 1983 HARN StatePlane Colorado Central FIPS ...
3
votes
1answer
261 views

How to convert a geotiff from WGS84 to 3857 with gdalwarp?

I'm trying to convert images with WGS84 projection to 3857 but warp is not giving me a output I would expect. This is my command: gdalwarp -s_srs "+proj=merc +datum=WGS84" -t_srs "EPSG:3857" ...
1
vote
2answers
157 views

Proper gdaltrasform syntax to transform a list of coordinates?

this is probably a very simple question, but I'm very new to GIS so I just need one last nudge. I've got a sense of the Linux utility gdaltransform and I am feeding it coordinate pairs in ...
2
votes
1answer
202 views

How do I convert EPSG:26986 coordinate pairs to EPSG:4326 from the MassGIS web service, the Linux command-line, or PHP?

I'm a GIS newbie, normally a PHP web applications developer. I am trying to map all boundaries of the MA state representative districts. So I just need to convert polygon coordinates from the ...
12
votes
3answers
5k views

How to georeference a web mercator tile correctly using gdal?

As an example I will take the following tile http://a.tile.openstreetmap.org/3/4/2.png and save it as "4_2.png". The WGS84 coordinates of this tile can be calculated or read there by clicking the ...