View shed tool-sample spacing...
oliver
Global Mapper User
Hi,
I am trying to check the visibility of a tower in a landscape,
I have some results but I would like to refine it as I am not very happy with the resolution of the analysis.
I used an .hgt file 100m for the elevation data map,
and I am trying to study the visibility of a tower 30-35 m above ground in a 5km radius,
I don't have a very good understanding of mapping yet,
and I wonder which resolution can I work at ? and which sample spacing should I use to have an optimal result ?
Thanks for your help.
I am trying to check the visibility of a tower in a landscape,
I have some results but I would like to refine it as I am not very happy with the resolution of the analysis.
I used an .hgt file 100m for the elevation data map,
and I am trying to study the visibility of a tower 30-35 m above ground in a 5km radius,
I don't have a very good understanding of mapping yet,
and I wonder which resolution can I work at ? and which sample spacing should I use to have an optimal result ?
Thanks for your help.
Comments
-
The default sample spacing should reflect the resolution of the most detailed available elevation layer. The SRTM HGT files generally have horizontal resolution of 3 arc seconds (about 90 meters), so going much beyond that won't make too much difference, although you might get a slightly better picture by halving the default sample spacing. To get even better resoluts you would need to obtain higher resolution elevation data, which may be difficult depending on what area of the earth you are working on.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com
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