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Hi Brian, re: > Hi Tom, I did a google search on the "gini format" and got a Unisys site that > described the same format I am looking at in the ICD document. Namely, a 512 > byte header followed by a data portion. I see the data portion can be > compressed, which would account for the different record lengths. (No mention > is > made of compression technique.) However, I am not finding anything that looks > like the header in the product. Is it possible the entire product is getting > hit > by some compression technique before it is sent out? Yes, exactly. The products are Zlib-compressed in chunks for broadcast in NOAAPort. Both Unidata McIDAS and GEMPAK have incorporated the code necessary to uncompress the image pieces on the fly for display and analysis. In addition, the standalone 'zlibg2gini' "decoder" in the ldm-mcidas package contains the code that uncompresses the images into the format described in the ICD you are referencing. I would say that your easiest path toward using the images would be to download the ldm-mcidas package; copy the 'zlibg2gini' decoder executable to a directory in the PATH of the user running your LDM (e.g., ~ldm/decoders, NOT ~ldm/bin!!); and have the decoder write out uncompressed files. At that point you would have images that you can work with. The ldm-mcidas package is available by anonymous FTP from the Unidata FTP server, ftp.unidata.ucar.edu. There is a binary distribution built for old Linux systems that you might be able to use "out of the box". Here is the access information: <as 'ldm'> cd ~ldm mkdir ldm-mcidas cd ldm-mcidas ftp ftp.unidata.ucar.edu <user> anonymous <pass> address@hidden cd pub/ldm-mcidas binary get ldm-mcidas-2004.tar.Z <- source distribution -- OR -- cd pub/binary/linux_2.6-i686 binary get ldm-mcidas-2004.tar.Z <- old binary distribution for 32-bit Linux quit tar xvzf ldm-mcidas-2004.tar.Z cp ldm-mcidas-2004/bin/zlibg2gini ~/decoders cp ldm-mcidas-2004/etc/SAT* ~/etc Here is a generic one that uncompresses the GINI images from the NIMAGE datastream: ######################################################################### # # NIMAGE (NOAAPORT imagery) section using using LDM-MCIDAS 'zlibg2gini' # decoder # # NOTEs: # - stop and restart the LDM to activate # ######################################################################### # All NOAAPORT Zlib-compressed (satz) GINI images NIMAGE ^satz/ch[0-9]/.*/(.*)/([12][0-9])([0-9][0-9])([01][0-9])([0-3][0-9]) ([0-2][0-9])([0-5][0-9])/(.*)/(.*km)/ PIPE -close zlibg2gini -vl logs/ldm-mcidas.log data/mcidas/images/sat/\8/\9/\1/\1_\2\3\4\5_\6\7 NB: - you must take care to use tabs in appropriate places in pattern-action file patterns: - tab between NIMAGE and ^satz - tab before PIPE - tab between PIPE and -close - tab before zlibg2gini - tab before data/mcidas/... - you should adjust the output directory to suit your needs If you need to build 'zlibg2gini' from source and run into problems (quite possible), please open a new inquiry by sending a new email (not a reply) to address@hidden. > I am seeing the WMO header, > followed by two CRs and a LF, then after that I was expecting the 512-byte > header, but what is there is not the header. Is there additional stuff there > before the actual data product starts? The stumbling block for you at the moment is the zlib-compressed blocks that are created for the NOAAPort broadcast. Question: - do you really need to write a new decoder for the GINI images? - another way of asking the same question is how are you intending to use the NIMAGE GINI images? Again, both Unidata GEMPAK and McIDAS have been configured to use the zlib-compressed images as is (they, of course, can also use the uncompressed images). > Thanks... Brian No worries. Cheers, Tom -- **************************************************************************** Unidata User Support UCAR Unidata Program (303) 497-8642 P.O. Box 3000 address@hidden Boulder, CO 80307 ---------------------------------------------------------------------------- Unidata HomePage http://www.unidata.ucar.edu **************************************************************************** Ticket Details =================== Ticket ID: OLV-956032 Department: Support IDD Priority: Normal Status: Closed