Bug report #6472
Qgis 1.8.0 converts WGS84 to OSGB36 incorrectly
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: | - | ||
| Category: | - | ||
| Affected QGIS version: | master | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 15703 |
Description
In attempting to georeference old OS maps I noticed that converting lat/long to OS grid gives different results to coordinates provided by OS, e.g. on Streetmap.co.uk. Coordinates from Google maps via OpenLayers with on-the-fly reprojection give similar incorrect results. To replicate Settings>Custom CRS. In Test section give parameters +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +datum=OSGB36 +units=m +no_defs and 53.5502777778, 1.8008333333 and calculate result. In 1.7.0 & 1.4.0 the results are 413293 405979 which compares with Streetmap's coordinates for the same point. On 1.8.0 the result is 413194, 406006
To find the location on www.streetmap.co.uk search for Cartworth. The location is the junction of Cartworth Moor Rd & Weather Hill Lane.
Platform is Debian Squeeze AMD 64
History
#1
Updated by Ian Goddard over 11 years ago
After some more checking, 1.8.0 is OK on windows & master is OK on Squeeze. Maybe it's a problem with one or two specific builds.
Updated by