slus boila

[atrebbi]

I am writing a software to convert to gauss boaga. In reality it converts to epsg 3003 and epsg 3004 , but I would like to understand how to pass from this to gb : I think I have understood that according to the longitude I should choose one or the other, make conversion and then add a constant .
Does anyone know exactly what values I have to use for various comparisons?

(the software I'm working on is this: https://itunes.apple.com/us/app/gps-units-converter-lite/id730307912?mt=8 )

 

[Tristan]

What's the point of writing a gb conversion software now? is a coordinate system that is now 75 years old and is going into disuse... Besides on the net is full of software that already egregiamente do this job

 

[atrebbi]

What's the point of writing a gb conversion software now? is a coordinate system that is now 75 years old and is going into disuse... Besides on the net is full of software that already egregiamente do this job

I answer only to avoid someone seeing his answer, you think my problem is solved.
and I renew my request on conversion to gb

 

[Tristan]

Well, since you have time to lose, check out the proj4 libraries

 

[atrebbi]

Okay, I'll give you a recap.
I use proj4 and gdal/ogr for conversion to epsg 3003 and 3004 which are the two fuses of gb, for a fuse the coordinates seem to me to correspond, for the other seems to me to be added a constant, I do not remember which; moreover I do not remember that they meridian to apply one or the other transformation.
If you can give me these info you make me a pleasure, because I tried to look for them but I didn't find them . If you don't love it, don't respond, it's not mandatory and you avoid me to keep answering to make it clear that the problem is not solved

 

[Tristan]

I should like to add a constant one, I do not remember which one, and I do not remember that they should apply one or the other transformation.

If you're talking about the fake east, it's 1500000 for the west side and 2520000 for the east side, but it's not clear from your request what you're asking

 

[atrebbi]

If you're talking about the fake east, it's 1500000 for the west side and 2520000 for the east side, but it's not clear from your request what you're asking

ok ; the other thing I need to understand is where to apply the one or the other transformation, I have in input the gps coordinates (in wgs84 ), I should understand from these that transformation apply (epsg 3003 or 3004 ) and then how to change the obtained result ( false east )

but in the zones between the fuses I have discontinuities?

I would also need something to verify the calculations (maybe a trusted web service, one of those you say abound but I couldn't find )

 

[studio.avarino]

Hi.
maybe you can find something useful here:
http://www.borneo.name/topo/topo.html

 

[Tristan]

I would also need something to verify the calculations (maybe a trusted web service, one of those you say abound but I couldn't find )

post-wet cartlab

 

[atrebbi]

I tried one of the coordinate transformation services for the point (45.9) Gttps:/www.dropbox.com/s/0unuvs00ebyn0k/screenshot 14-08 15.54.35.pngif I turn it with epsg 3003, I get different values
(5731141.571997,1226298.231222)
I tried to insert the values (transformed) which I read as utm32 / ed50 in the same screen and get a still wrong value (the error increases ) :
(5735513.392705.1224485.243577)
apart from the doubt that to be wrong could be the value returned from the indicated site (which is: http://www.geoin.it/coordinate_converter/ ) , che cosa sto sbagliando ?



ogrspatialreference src, dest;

src.setwellknowngeogcs("wgs84");
dest.importfromepsg(3003);

ogrcoordinatetransformation *gbfusoovest = ogrcreatecoordinatetransformation( &src, &dest);

 

[atrebbi]

This then gives me absurd values: https://www.dropbox.com/s/br3cx37ackpq/screenshot 14-08-032016.18.46.
cfr: http://www.ultrasoft3d.net/conversione_coordinate.aspxWhat is the correct value for the point (45.9)?

 

[atrebbi]

This comes back with the value I calculated:http://geoportale.regione.emilia-romagna.it/services/services technici/service-di-conversion/cts
cfr: Gttps://www.dropbox.com/s/m5uysqck23itn/screenshot 14-08-04 .25.25png