[Mapserver-users] ESRI Ascii grid format...

[Bruce Raup]

On 2004-06-22 15:13 -0600,  Jason M. Nielsen wrote:

> I have some ascii files dumped as the AAIGRID format from gdal. These are esri
> ascii grids.
>
> The format appears simple:
> ncols        98
> nrows        172
> xllcorner    1044355.808370659710
> yllcorner    10042832.567399607971
> cellsize     91.442854747403
> *then the z values are listed for each line*
>
> Problem is I dont know which friggin way these go. I tried left to right
> starting lower left and incrementing x and y. I end up with skewed data.
>
> Does anyone know where I can get the specs on this format that explicitly
> explain in thorough detail how its formated?

I'm pretty sure the first z-value is the upper-left corner of the grid, and
that it proceeds left-to-right, then down.  I have used GMT (Generic
Mapping Tools (http://gmt.soest.hawaii.edu/)) to handle such files, and had
success using these assumptions.  Sorry, but I don't know where the specs
are.

Bruce

-- 
Bruce Raup                                               Phone:  303-492-8814
National Snow and Ice Data Center, U. of Colorado, 449 UCB, Boulder, CO 80309
http://cires.colorado.edu/~braup/