[GRASS-dev] [GRASS GIS] #1733: r.out.kml fails close to UTM Zone boundary

[Casey Vandenberg]

Thanks Hamish,

I am quite content projecting all data into WGS84 Lat/Long. I agree that 
is much better than producing a misaligned output. I just wasn't sure if 
that was the intended functionality at the time of trying the program.

Cheers,

Casey

On 12-09-17 10:07 PM, GRASS GIS wrote:
> #1733: r.out.kml fails close to UTM Zone boundary
> -------------------------+--------------------------------------------------
>   Reporter:  voncasec     |       Owner:  grass-dev@…
>       Type:  enhancement  |      Status:  new
>   Priority:  minor        |   Milestone:  6.4.3
> Component:  Addons       |     Version:  6.4.2
>   Keywords:  r.out.kml    |    Platform:  Linux
>        Cpu:  x86-64       |
> -------------------------+--------------------------------------------------
> Changes (by hamish):
>
>    * type:  defect => enhancement
>
>
> Comment:
>
>   Hi, the author here.
>
>   The number 1 solution is to reproject into lat/lon. It's KML's native,
>   everything else is a shoe-horn.
>
>   The convergence angle check for < 1px per 1280x1024 image size is provided
>   as a convenience for the cases where you can mildly get away with doing
>   the wrong thing without causing too much damage.
>   It is measured at the center of the current computational region.
>
>   from the help page:
>   {{{
>   KML expects data to be in Latitude-Longitude using the WGS84 datum and
>   EGM96 vertical datum. This script will work for non-geographic map
>   projections, but only if the projection's local deviation from true-north
>   (the convergence angle) is small enough to ensure correct output. You can
>   use the r.proj module from a Latitude-Longitude location to
>   reproject maps if needed.
>   At this time vertical datum is not checked by this module as support for
>   it is relatively new in r.support and r.info.
>   }}}
>
>
>   I'm not in favour of letting the module produce broken and misaligned
>   output. If you wish to bypass the check on your own, edit the script in a
>   text editor and on line 126 comment out the "exit 1" by putting a '#'
>   symbol in front of it.
>
>   But it is much better to just reproject to LL and run the module in a
>   lat/lon location, then the alignment will be perfect and the module will
>   be happy.
>
>
>   cheers,
>   Hamish
>


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