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choose to proceed with downloading the 
data or modifying the parameters of the 
request if the data volume is too large. In 
addition, users can optionally choose to 
have the data compressed just prior to 
transfer using standard UNIX or GNU gzip 
compression resulting in up to a five time 
reduction in the size of the data transfer. In 
1995 the DAAC's WWW server and DDS 
handled more than 5,247 network requests 
for global 1-km data set products totaling 
more than 112 gigabytes of data. 
Summary 
The compression/decompression technique 
developed for the global land 1-km AVHRR 
data set provides several capabilities that 
are beneficial to the user and the EDC 
DAAC. The technique provides the user 
the capability to subset the data set 
spectrally, spatially, and geographically. 
The technique provides the EDC DAAC an 
efficient method for storage and retrieval of 
the data from near-line storage. The 
experience gained from network distribution 
of the data set will be used to develop the 
distribution techniques for NASA's Mission 
to Planet Earth Program. 
References 
Eidenshink, J. C. and Faundeen, J. L., 
1994, The 1 km AVHRR global land data 
set first stages of implementation. The 
International Journal of Remote Sensing, 
15, 3443-3462. 
Food and Agriculture Organization of the 
United Nations, 1990, Expert Consultation 
on Forest Resources Assessment 1990 
Project, FAO Headquarters (Rome: Forest 
Resources Assessment). 
Gallo, K. P., McNab, A. L., Karl, 7. R., 
93 
Brown, J. F., Hood, J. J., and Tarpley, J. D., 
1993, The use of vegetation index for 
assessment of the urban heat island effect: 
The International Journal of Remote 
Sensing, 14, 2223. 
Kess, B. L., Steinwand, D. R., Reichenback, 
S.E.,1994. Compression of the Global 
AVHRR 1-KM Data. IGARSS'94 Digest, 
Vol. 1, pp. 323-325 
Kidwell, K. B., 1991, NOAA Polar Orbiter 
Data Users' Guide, National Oceanic and 
Atmospheric Administration, World Weather 
Building, Room 100, Washington, D.C. 
Nelson, M., 1991, The Data Compression 
Book (Redwood City, California: M&T 
Books). 
Running S. W., Justice, C. O, 
Salomonson, V. V., Hall, D., Barker, J., 
Kaufmann, Y, J., Strahler, A. H., Huete, A. 
R., Muller, J.-P., Vanderbilt, V., Wan, Z. M., 
Teillet, P., and Carneggie, D., Terrestrial 
remote sensing science and algorithms 
planned for the Moderate Resolution 
Imaging Spectrometer (MODIS) of the Earth 
Observing System (EOS): The 
International Journal of Remote Sensing, 
15, 3587-3620. 
Steinwand, D. R., Mapping raster imagery 
to the interrupted Goode Homolosine 
Projection. The International Journal of 
Remote Sensing, 15, 3463-3471. 
Townshend, J. T. (editor), 1992, Improved 
Global Data for Land Applications. IGBP 
Global Change Report No. 20. The 
International Geosphere Biosphere 
Programme: A Study of Global Change of 
the Council of Scientific Unions, Stockholm. 
Townshend, J. R. G., Justice, C. O., Skole, 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996