Hi,
I got interested in testing how I could deliver two kind of raster imagery
through MapServer WCS. First set is aerial orthophotos, which I would like to
download in GeoTIFF, Erdas Imagine .img and ECW formats. Other data set
consists of 7-band satellite images. I had in my mind to select from one to
seven bands from the satellite images in free order and download them in
GeoTIFFs or .img format, and also in ecw format if the band count happens to be
three.
I managed to set up MapServer WCS service (even if the documents I found were
not extremely clear) and I was rather satisfied with the first results I got
with my aerial photos. My 3 GHz Pentium was sending images in GeoTIFF format to
the network at a rate of 3 megabytes per second. However, with multichannel
imagery I was not able to get everything work as I hoped. Perhaps somebody
could answer to following questions:
1. Is it possible to set up a raster layer for delivering 7-band imagery in
GeoTIFF/img formats? If it is, how? I tried with setting "wcs_bandcount" "7"
in the LAYER METADATA, but that lead to error message saying that band count
can not be higher that four. The NetCDF example I found from the use case
document makes me think that it might be possible with some 'wcs_rangeset'
settings.
I just noticed that I did not try img output but only GeoTIFF. Perhaps there is
something wrong with my outputformat settings? I were using the format I took
from some example in the documents:
OUTPUTFORMAT
NAME GEOTIFF
DRIVER "GDAL/GTiff"
MIMETYPE "image/tiff"
IMAGEMODE "BYTE"
EXTENSION "tif"
END
2. Does layer PROCESSING directives have any effect with WCS? I was trying to
select certain bands from 7-band imagery by setting for example PROCESSING
"BANDS=7,4,2" in LAYER definitions, but I received always just band combination
1,2,3. In this case I used "wcs_bandcount" "3". In addition to BANDS I would
like to use also LUT and RESAMPLE options with WCS.
3. I have used wget for downloading from my WCS service and it works fine. I
had installed one 'real' WCS client but it did not like my MapServer WCS
service. Are there some WCS clients that are known to work well with MapServer
WCS?
Regards,
-Jukka Rahkonen-
