2013Mar_CDED_NLCD  readme 
March 11, 2013

This readme file pertains to the Canadian Digital Elevation Data (CDED) and National Land Cover Data (NLCD) datasets, which have been compiled for use with TVStudy.

These datasets are not distributed with TVStudy itself (January 2013 release) because they are not needed for OET-69 studies conducted in U.S. territory.  The CDED dataset is used
for studies in Canadian territory.  The NLCD dataset is used for studies using the methodology of OET-72 and OET-73. 

The data consist of two directories:  NLCD and CDED.  Within each directory are files containing the complete terrain or land cover data sets necessary to run under tvstudy.   

Each directory was archived to a single file, 2013Mar_nlcd.tgz and cded.tgz, using the standard archive tool, gzip.  The sizes of the resulting .tgz files are about 1.03 GB and 13.2 GB.

Due to its large size, the cded.tgz file was then split into seven segments of about 2 GB each.  Those seven segments have been posted to data.fcc.gov and can be downloaded and concatenated by the end user.  The resulting .tgz file is then unzipped to recover the directory and its contents.

To minimize the possibility of transmission errors, the seven segments have been used to create parity archive (PAR2) files with Reed-Solomon error correction (5% redundancy).  While not strictly required to recover the original .tgz file, it is recommended that the user also download the PAR2 files and use appropriate software to verify (and correct if necessary) the seven segments comprising the .tar file.

A number of no-cost applications are available for utilizing the PAR2 functionality, including:

	MacPAR Deluxe (for the Macintosh) can be used to verify and correct the .tgz file segments using the PAR2 files.
	PyPar2 for the Linux platform has similar functionality.
	Multipar for the Windows platform.

Once the seven segments are recovered, they can be concatenated using Split & Concat (Mac) or the cat command (Linux) to create the .tgz file.  

Windows users should use 7-Zip to concatenate the seven segments and extract the Archive.tar file.  Once 7-Zip is installed, right-click on the first segment (.001) and choose "Extract files..." from the menu. 

Other applications may also be used to accomplish the above functions.

The CDED and NLCD directories (and their contents) should replace the empty CDED and NLCD directories that were distributed with TVStudy (January 2013 release).


For questions, contact   robert.weller@fcc.gov   202/418-7397