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FM output_map.nc missing latitude and longitude data

PE
Peter Egli, modified 4 Years ago.

FM output_map.nc missing latitude and longitude data

Youngling Posts: 0 Join Date: 2/4/16 Recent Posts
Greetings,

I have only used Delft 3D Flexible Mesh for 5 days so this may very well be a configuration issue:

The model coordinate system was set to NAD83(HARN)/UTM Zone 19N. My land boundary file was converted from WGS84[EPSG:4326] to NAD83(HARN)/UTM Zone 19N. The NGFGRID coordinate system was set to Cartesian. I was successful at building, running, and displaying a very simple hydrodynamic scenario; however the resultant output_map.nc file contained all fill values for NetNode_lon and NetNode_lat. NetNode_x and NetNode_y appear accurate.

Is there a set-up configuration that I missed?

Thank you in advance
MK
Michal Kleczek, modified 4 Years ago.

RE: FM output_map.nc missing latitude and longitude data (Answer)

Padawan Posts: 53 Join Date: 10/23/14 Recent Posts
Dear Peter,

Thank you for joining the Delft3D Flexible Mesh community.
If I understand correctly, your simulations were not affected by not filled variables NetNode_lon and NetNode_lat.
These variables are currently always in a map output (and network file), however, in case of both variables they are only filled when your coordinate system is spherical. If your coordinate system is as you reported - Cartesian, then these two values are just filled with a fill value ('_').
Perhaps in a new release these variables will be reported only when proper coordinate system is selected.
I hope this answers your question. Overall this should not influence your simulation, results or performance.

Kind regards,
Michal
PE
Peter Egli, modified 4 Years ago.

RE: FM output_map.nc missing latitude and longitude data

Youngling Posts: 0 Join Date: 2/4/16 Recent Posts
Michal,

Thank you for your reply.
Our simulations are running fine in UTM coordinates and it is easy enough change the projection (if necessary) in post-processing. I guess I was under the assumption that NetNode_x and NetNode_y would contain UTM coordinates and NetNode_lat and NetNode_lon would contain the transformed spherical coordinates. When we run our Delft 3D FM model in Spherical coordinates, NetNode_lat and NetNode_lon are not included in the resultant _map.nc file while NetNode_x and NetNode_y are reported in units of lat/lon.

It seems, however, that the polygon refining tools do not function in Spherical Coordinates?

Thanks again!
Pete
MK
Michal Kleczek, modified 4 Years ago.

RE: FM output_map.nc missing latitude and longitude data

Padawan Posts: 53 Join Date: 10/23/14 Recent Posts
Dear Peter,

Thank you for your remarks.
Indeed, it is rather confusing that NetNode_lat and NetNode_lon do not appear in the map files while using spherical coordinates, and they are not filled in case of cartesian coordinates. We hope to include the correction for output in the coming release.
The RGFgrid team is working on a solution for the issue you have encountered with polygon refinement. Indeed, when you have Spherical Coordinates the polygon refinement tool does not respond.

I hope these issues are not too cumbersome for your work.

Once again thank you for your remarks and let us know in case any other questions, concerns arise.
Michal