Coordinate conversion

:banghead:

Anyone know of a good tool to convert coordinates in UTM33 to WGS84 :confused:

I have some MrSid files converted to BMP that I want to use as background in Ground2k4.
They are in one meter resolution and 5000x5000pixels with information about upper-left and lower-right corners in meters (a good guess is that those meters are referenced to lat 0/long 0 somehow).

/Bqt
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
I wouldn't know a good tool for that.

But do you know which coordinate system they use? I have used some Dutch photos and they had a Dutch coordinate system (RD coordinates). And later I worked with some Irish data and that had an Irish Grid coordinate system. Both these systems were in meters with a certan 0,0 point. But before you can convert it to lat/lon you need to know which system it is.

So I would advice you to first find out which coordinate system it exactly is and then search for some specific conversion formulas. On GIs sites I have found them usually (google helps with that :)).
 

bpahe

Resource contributor
Hi!

Should it turn out that it is the national Swedish system, RT90, then there is a perfect tool at Lantmäteriet, which converts from RT90 to WGS84. I use it to calculate all coordinates that are needed in SceneryBuilder. The adress to this site - in Swedish - is:

http://www.lm.se/geodesi/program/gtransrv/gtransframe.htm

Tip: Use the simple version at the bottom of the page - "enkel koordinattransformation"!

/hans
 
Man tackar för hjälpen, borde kollat hos Lantmäteriet själv :eek:

Thanks, checked it out, converted and tried out in Ground2k4.
Looks decently accurate, guess 200m error is what you expect on a 25km bitmap. :eek:
Guess I'll reduce the size and work with 3x3km, one for each airfield.
But it would be nice to have the surrounding lakes and roads in aswell.

OK, more :coffee: ! Back to work.

/Bqt
 

bpahe

Resource contributor
Hejsan!

Well, glad that worked out! :)

That tool is quite good, too bad it is not a free stand-alone product anymore. Might I ask what area of the world your working with? My qualified guess would be Sweden, of course, but which airfields/cities?

/hans
 
Yo!

Just a project that has ben going on and off for a couple of years.
Mainly some fields around Bollnäs, where i did my PPL, but also the ones surrounding Borås.

/Bqt
 
Hey,

ERDAS ViewFinder2.1 is a freeware tool that allows raster image reprojection. But I have been having a bit of trouble with my LANDSAT1990 MrSid images. So if you have any luck I will be interested to know about it...Follow the link then go to free downloads...

http://gis.leica-geosystems.com/erdascentral/

You may need to use the ECW Compressor and install the ECW Plugin for ViewFinder...

http://www.digitalgrove.net/image_reprojection_with_erdas.htm

I posted about this on the Avsim forum as well, so check that out as there has been a bit of discussion about it.

Cheers,
Derek
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
Hi Derek,

I am going to try it on some photos I have here. I will let you know if I get it working properly.
 
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