[GRASS-user] Re: Space Oblique Mercator (SOM) and "lsat" project code

[Dylan Beaudette]

On Sunday 18 June 2006 01:59, Anders Fahlén wrote:
> Hi,
>
> I'm new to GRASS - bear with me:-)
>
> Currently I'm working on a watershed risk
> assessment task where I have Landsat TM data
> spanning over a 20 year period. In order to
> convert all the different Landsat projections to
> one common georeferenced ground I want to import
> the raster files into separate mapsets with
> original projections as a first step.
>
> One set of data is from USGS (Landsat 5 TM .tif
> files) based on Space Oblique Mercator (SOM) projection.
>
> Here is my problem: How do I correctly transform
> the metadata information from the USGS Landsat 5
> .hdr file using the 'lsat' projection code in
> GRASS (using GRASS 6.1 cvs, WINDOWS version)?
>
> The .hdr file received from USGS reads as follows:
>
>   "PRODUCT =00240248-01 WRS =130/04500
> ACQUISITION DATE =19921111 SATELLITE =L5
> INSTRUMENT =TM10 PRODUCT TYPE =ORBIT ORIENTED
> PRODUCT SIZE =FULL
> SCENE
> TYPE OF GEODETIC PROCESSING =SYSTEMATIC
> RESAMPLING =CC RAD GAINS/BIASES =
> 00.00398/-0.0100 00.00964/-0.0232
> 00.00540/-0.0078 00.01043/-0.0193
> 00.00235/-0.0080 00.00000/0.00000
> 00.00154/-0.0040 TAPE SPANNING FLAG=1/1 START
> LINE #=    1 LINES PER VOL=40096 ORIENTATION =
> 86.36 PROJECTION =SOM  USGS PROJECTION # =    21
> USGS MAP ZONE =   100 USGS PROJECTION PARAMETERS
> =   0.637813700000000D+07   0.669437999000000D-02
>    0.988800000000000D+02   0.144000000000000D+04
>   0.980130120103547D+08   0.129299998692014D+03
> 0.233000000000000D+03   0.339078914728310D-19
> 0.339078914728310D-19   0.339078914728310D-19
> 0.339078914728310D-19   0.339078914728310D-19
> 0.339078914728310D-19   0.339078914728310D-19
> 0.130000000000000D+03 EARTH ELLIPSOID
> =WGS84                SEMI-MAJOR AXIS
> =6378137.000 SEMI-MINOR AXIS =6356752.314 PIXEL
> SIZE =30.00 PIXELS PER LINE= 6920 LINES PER
> IMAGE= 5728 UL 1000636.4421E
> 223245.7618N  17609006.551    241587.518 UR
> 1015119.6129E
> 221736.3799N  17620546.108    423081.037 LR
> 1012926.4911E
> 204635.4062N  17791358.336    401458.922 LL
> 0994549.6437E
> 210131.2130N  17779824.490    220055.220 BANDS
> PRESENT =1234567 BLOCKING FACTOR =   1 RECORD LENGTH = 6920 SUN
>   ELEVATION =42 SUN AZIMUTH =142 CENTER
> 1004816.6229E
> 213945.8926N  17700964.419    321293.145  3349  2865 OFFSET=  28 REVB"
>
> How do I correctly convert this info to the
> "lsat" project code command structure in GRASS?
> Some parameters are obviously known from the
> header file info, e.g. Satellite Number (= 5),
> Satellite Path Number (= 130), ellipsoid name (=
> wgs84). How about the remaining info?
>
> Secondly, is there a way to make on the fly
> project conversions, from SOM to UTM 47, using the OGR tool?
>
> Thanks for any hints on how to proceed.
>

See what gdalinfo thinks about these files. If it can read their coordinate 
system, chances are that you will be able to warp them to any new coordinate 
system with little difficulty.

Cheers,


-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341