Re: high resolution coastlines

["Mark Hadfield" <m.hadfield(at)niwa.cri.nz>]

Julie Greenwood <julieg@NOSPAMoceanweather.com> wrote in message
news:saoivr6q2pd44@corp.supernews.com...
> Hello Everybody
>
> I wonder if anyone has adapted the World Vector Shoreline or something
> similar for use with IDL.  I find the 'hires' coastlines included with IDL
> to be deficient for my needs.

Me too.

Don't bother with the World Vector Shoreline, get the Global
Self-consistent, Hierarchical, High-resolution Shoreline Database:

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

It's a group of shoreline datasets at several different resolutions, based
on WVS and other datasets, but cleaned up (intersecting segments removed
etc):

I mentioned this on the group in December and got a reply from Liam Gumley
who has done some work on reading & displaying this dataset. Part of his
message is included below my signature.

---
Mark Hadfield
m.hadfield@niwa.cri.nz  http://katipo.niwa.cri.nz/~hadfield/
National Institute for Water and Atmospheric Research
PO Box 14-901, Wellington, New Zealand


*** Excerpt of message from Liam Gumley ***

I've played around with converting this dataset to IDL coastline format,
because as you've noted, the IDL coastline data is not too flash. I've
put the relevant files online, feel free to grab any or all of them:
(ftp://origin.ssec.wisc.edu/pub/gumley/IDL/gshhs/)

gshhs_frames.xdr -> a saved frame file that you can display with
FRESTORE:
(http://cimss.ssec.wisc.edu/~gumley/frame.html)
It shows the difference in quality between the IDL coastline and the
GSHHS coastline data off the tip of Florida.

gshhs_to_idl.pro -> a procedure for converting GSHHS format to IDL map
format.

map_con.pro -> a modified version of map_continents.pro which uses the
coastline data derived from GSHHS. It works in quite a few cases, but in
some cases it failed to draw the coastlines properly (I think Africa had
some problems).

phigh.dat, phigh.ndx -> GSHHS data converted to IDL format (used by
map_con).