Comments regarding gmt-gshhg_2.3.4-1_amd64.changes

[Sebastiaan Couwenberg]

Hi Thorsten,

Thanks for your work on the NEW queue and the quick feedback on this
recent package.

On 06/09/2015 10:04 PM, Thorsten Alteholz wrote:
> somewhere I read that these datasets are built from other sources. 

This is documented in the package description and GSHHG homepage. The
latter contains links to the three public domain datasets it's
amalgamated from. To quote:

"
 We present a high-resolution geography data set amalgamated from three
 data bases in the public domain:

  1.  World Vector Shorelines (WVS).
      http://shoreline.noaa.gov/data/datasheets/wvs.html
  2.  CIA World Data Bank II (WDBII).
      http://www.evl.uic.edu/pape/data/WDB
  3.  Atlas of the Cryosphere (AC).
      http://nsidc.org/data/atlas/

 The WVS is our basis for shorelines except for Antarctica while the
 WDBII is the basis for lakes, although there are instances where
 differences in coastline representations necessitated adding WDBII
 islands to GSHHG. The WDBII source also provides all political borders
 and rivers. The addition of AC since 2.3.0 allows us to offer two
 choices for Antarctica coastlines: Ice-front or Grounding line. These
 are encoded as levels 5 and 6, respectively and users of GSHHG can
 choose which set to use. GSHHG data have undergone extensive
 processing and should be free of internal inconsistencies such as
 erratic points and crossing segments. The shorelines are constructed
 entirely from hierarchically arranged closed polygons.
"

http://www.soest.hawaii.edu/pwessel/gshhg/index.html

> Could you provide theses sources as well in the package?

Including references to these sources in the copyright file or
README.Debian is no problem, including the databases themselves is a bit
problematic besides the significant increase in package size.

The WVS dataset can be ordered on CD for $196.25, or downloaded for free
via the GSHHG dataset.

http://www.ngdc.noaa.gov/mgg/shorelines/

To build the GSHHG dataset from source we'd need to implement the
processing and assembly of the GSHHG data as described in their paper.

See: http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html

Kind Regards,

Bas

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