Two LAT of bathy (XYZ) post processing - different benchmark values
Ioannis.mag
Global Mapper UserTrusted User
Hi,
I have two sets of XYZ data (say A and
They overlap partially and from that I can tell that they have not been referenced to the same LAT (lowest astronomical tide).
So although they partially represent the same part of the seabed, there is a jump where they overlap by 0.5m.
In other words for the same X and Y, the Z for A = the Z for B +0.5m
Can I choose A as benchmark set and ask Global Mapper to create another XYZ file from B but in this case it will be +0.5m for all its Z value? So there will be no step when I extract profiles, create contours etc.
I have been trying with the Terrain Analysis feature but I dont seem to be able to get what I want and unless I am missing something I dont think it is the right GM menu option.
Many thanks for your help.
Ioannis
I have two sets of XYZ data (say A and
They overlap partially and from that I can tell that they have not been referenced to the same LAT (lowest astronomical tide).
So although they partially represent the same part of the seabed, there is a jump where they overlap by 0.5m.
In other words for the same X and Y, the Z for A = the Z for B +0.5m
Can I choose A as benchmark set and ask Global Mapper to create another XYZ file from B but in this case it will be +0.5m for all its Z value? So there will be no step when I extract profiles, create contours etc.
I have been trying with the Terrain Analysis feature but I dont seem to be able to get what I want and unless I am missing something I dont think it is the right GM menu option.
Many thanks for your help.
Ioannis
Comments
-
Ioannis,
When you load the data set B with the File->Open Generic ASCII Text File menu command there is a Point Offset/Scale button. Use that to provide a 0.5 offset for the Z values to adjust them on import to match A.
Thanks,
Mike
Global Mapper Guru
gmsupport@bluemarblegeo.com
http://www.bluemarblegeo.com/
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