EPSG:27700 (OSGB)

[CharlesHarrison]

With the definitions ...

Proj4js.defsEPSG:27700? = "+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 "; EPSG4326 = new Proj4js.Proj( "EPSG:4326" ); EPSG27700 = new Proj4js.Proj( "EPSG:27700" );

... the point ...

{x: 0005038 /*E*/, y: 5104711 /*N*/}

... is transformed to ...

{x: -15.95172 /*W*/, y: 89.995772 /*N*/}

... instead of about ...

{x: -1.25 /*W*/, y: 51.31 /*N*/}

This can be seen by following this URL*:  http://www.macfh.co.uk/JavaJive/AudioVisualTV/TerrestrialTV/TerrestrialCalculator.php?iRxWhereHow=E&iRxEast=5038&iRxNorth=5104711

* Although this page uses a self-built version of Proj4js.js, I have checked that this also happens with the latest version downloaded from the site.

The line performing the transformation is line 1080 ...

var result=Proj4js.transform((irish?EPSG29902:EPSG27700),EPSG4326,{x:srcEast.getValue(),y:srcNorth.getValue()});

... where firebug shows that irish is undefined, so EPSG27700 is being used as the input system, inputs x and y are as expected, and the result returned by Proj4js.transform is erroneous as above.

[CharlesHarrison]

Replying to CharlesHarrison:

{x: 0005038 /*E*/, y: 5104711 /*N*/}

Apologies. This point is actually outside the area valid for OSGB36. Although I did check it against GridInQuest? before opening this report last night, I must have made a mistake when doing so, because when I realised that it was out of bounds, I just tried it again in GIQ, and now it is also saying that the point is out of bounds!

This ticket can be closed