3 replies to this topic

[Jan Helebrant]

Hi,
I have some data from my colleague - it is Microstation DGN with buildings in some industrial facility and some point data. I loaded it to QGIS, saved as shapefile and now I need to do some boreholes data analysis and also some maps.

Problem is, that the coordinates are in this format:

OBJECT X Y

Point_1 13,35 -75,24

Point_2 13,35 -75,26

Point_3 13,12 -75,37

Point_4 13,23 -75,31

Point_5 13,21 -75,38

all this data should be located in this area - northern part of Czech Republic (Central Europe) - I supplied a link to
Google Maps - the area is surrounded by the yellow roads on the west and north and by the bow-shaped railway.

I worked with some similar data, which were in JTSK, but this is surely not JTSK and I am unable to find out if this is any know CRS. I looked on spatialreference.org but without success. I also though about simple cartesian coordinates, but why negative "Y" values?

I sent email to my colleague but got no reply yet so asking also here.

thanks

[Hans van der Maarel]

Could be anything really. The problem with DGN is that it won't store coordinate system information, just the values (and even then there's enough room for confusion since it will only store integer values and relies on scale factors to report the correct numbers)

[Jan Helebrant]

Could be anything really. The problem with DGN is that it won't store coordinate system information, just the values (and even then there's enough room for confusion since it will only store integer values and relies on scale factors to report the correct numbers)

Thanks for the reply,
I was afraid of this

Because the shapes were too complicated and would take to much time to redraw them manually, I finally manually moved the shapes to WGS map area and used affine transformation tool for shapes available in Kosmo GIS to fit it semi-manually on georeferenced map from google using the buildings and roads as reference. It also needed more steps, but the result is ok and now I can combine it with Openstreetmap data in QGIS to produce some nice maps.

[Nick H]

It's good that you managed to sort this out, Jan. I did wonder if these were xy ordinate pairs plotted on a local grid having it's origin on a bench mark somewhere off to the south and east of the area in question.

Regards, N.