GCPs not read for Envisat MERIS reduced resolution scenes

[knutfrode]

Tested with GDAL versions 1.6 (Windows) and 1.8 (Linux), I find that GCP’s and coordinate systems (CS) are read for full resolution (MER_FR) scenes, but not for reduced resolution (MER_RR) scenes.

Here are the first output lines from gdalinfo for a reduced resolution (RR) scene:

Driver: ESAT/Envisat Image Format
Files: MER_RR__1PNRAL20100426_154828_000003662088_00498_42636_0001.N1
Size is 1121, 2081
Coordinate System is `'
Metadata:   
  MPH_PRODUCT=MER_RR__1PNRAL20100426_154828_000003662088_00498_42636_0001.N1
  MPH_PROC_STAGE=N
  MPH_REF_DOC=PO-RS-MDA-GS-2009_11_5A
  MPH_ACQUISITION_STATION=PDHS-K              
  ….

For corresponding full resolution scenes, CS and GCP’s are reported before the Metadata. This example scene, and others, can be downloaded from ​http://www.brockmann-consult.de/beam/data/products/MERIS

File structure for RR and FR scenes should be close to identical, so this probably requires a small fix only.