[Xastir-dev] Gerry C: Canadian Topo Maps, what to do with them?

[Curt Mills]

On Mon, 2 Feb 2004, Bob Nielsen wrote:

> I found a readme:
>
> The file vanmos.zip is composed of 16 ERS-1 images.  It is 4321 pixels
> by 3601 lines and contains 1 band of data.  The images were acquired
> between February 28, 1993 and April 23, 1993.  The geographic bounds
> are: Latitude 48° - 51° N and Longitude 123° - 129° W, with sampling
> intervals of 3 minutes (latitude) and5 minutes (longitude).
>
> The file vandem.zip is a digital elevation model of the same area as
> described above.  The file dimensions and boundaries are the same.
>
> In a quick look, I didn't see any definition and don't know how to
> interpret the data, but this may help:
>
> $ unzip -Z vanmos.zip
> Archive:  vanmos.zip   3665675 bytes   5 files
> -rw-rw-rw-  2.0 fat      595 t- defN 28-Apr-99 07:48 lisezmoi_vancouver.txt
> -rw-rw-rw-  2.0 fat      494 t- defN 28-Apr-99 07:48 readme_vancouver.txt
> -rw-rw-rw-  2.0 fat 15559921 b- defN 28-Apr-99 07:49 vanisl_mos.bil
> -rw-rw-rw-  2.0 fat       89 t- defN 24-Aug-00 14:07 vanisl_mos.hdr
> -rw-rw-rw-  2.0 fat      330 t- defN 25-Aug-00 14:28 vanisl_mos.aux
> 5 files, 15561429 bytes uncompressed, 3665105 bytes compressed:  76.4%
>
> vanisl_mos.hdr:
>
> BYTEORDER      M
> LAYOUT       BIL
> NROWS         3601
> NCOLS         4321
> NBANDS        1
>
> vanisl_mos.aux:
>
> BYTEORDER      M
> LAYOUT       BIL
> NROWS         3601
> NCOLS         4321
> NBANDS        1

Hey Gerry:  What format are these maps?  I think I remember
something about BIL on the GDAL mailing list.  Perhaps these are
simply strings of pixels, and you have to have the header in order
to interpret them?  What can we do with them right now, if
anything?

It sure looks like we just georeference them based on constant
lat/long, which should be easy to do in Xastir, assuming we can get
GDAL or something else to read them in.  Actually I think
ImageMagick might be able to do it if we can feed it in a raster
form it recognizes.

-- 
Curt, WE7U.				archer at eskimo dot com
http://www.eskimo.com/~archer
  Lotto:  A tax on people who are bad at math. - unknown
Windows:  Microsoft's tax on computer illiterates. - WE7U.
The world DOES revolve around me:  I picked the coordinate system!"