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NASA. It was then too late to change the contract, and the United States 
was committed to its own format, which was not considered acceptable by any 
of the other station operators. It was very LANDSAT-specific, and could not 
be adapted easily to other data. 
The LGSOWG then agreed to establish a sub-group of technical experts 
(LANDSAT Technical Working Group--LTWG) to attempt to define a new format 
which could be implemented when the  LANDSAT-4 system was to come into 
operation. The guidelines for the group were complex. The format was to be 
compact and simple, so that non-computer experts could understand it 
relatively easily. It was also to be flexible, convenient and suitable for 
a wide variety of data types from many sources. It should be possible to 
read the basic data without prior knowledge of its source. Ideally, the 
format should accommodate polygon data as vell as image raster and cellular 
data, however, where compromises were required, these were to favour image 
data (LGSOWG, 1979; EOSAT, 1985). 
The concept of a CCT Format Family originated from the situation which had 
developed within LGSOWG. Several members of the group had already adopted 
what they thought vas a standard developed jointly by CCRS, NASA and USGS. 
It was discovered that the NASA-USGS participants in that development were 
NOT involved in the design of the new NASA-USGS format, and to which the 
U. S. was then firmly committed. The technical group was split in terms of 
commitment. The immediate solution was to define a data header record which 
could be added to either of these formats to define their structure. Having 
accepted this concept of data structure definition (primarily so both groups 
could preserve their existing formats), it was then relatively easy for the 
technical people to tackle the task in a more logical fashion and develop a 
completely new format which vas vastly superior to either of the original 
ones, which were eventually discarded. 
Once the LTWG began to make significant progress in the development of a new 
standard, NASA sponsored a meeting in 1977 of a group of scientists 
representing NASA, other government agencies, private industry and 
universities. The original purpose of the meeting vas to obtain some user 
feedback on the new format standard being proposed, particularly from the 
community of users of Geographic Information Systems (GIS). The group vas 
largely indifferent to the specific data structure format. However, it was 
clear that the group wanted one standard which would be suitable for all 
future satellite imaging sensors. More important than the data format was 
the strong recommendation that satellite data be made available in a 
geographic referenced form (Simonett, et al., 1978). 
It should be noted that this meeting had a profound effect on the 
development of Canada's satellite processing philosophy. Canada had just 
completed the development of a new Digital Image Correction System (DICS). 
The new computer tape products vere about to be released, with geometric 
correction to UTM coordinates, but with image data generally oriented as 
scanned by the sensor. The message from the group at the meeting was that 
GIS users wanted data vith square pixels oriented along the UTM coordinates 
and keyed to maps. Several meetings were held with various Canadian user 
groups who confirmed this viewpoint. The original DICS products were 
scrapped, and since that time, all Canadian geometrically corrected data 
from LANDSAT, NOAA AVHRR, SEASAT and SPOT have been geocoded with square 
pixels :(505 m, -25- m, 12:5 m'or 6.250 on a side) aligned to the standard 
Canadian UTM map sheets.  (Guertin et al., 1984). 
The primary goal of the LGSOWG Format Family was to meet the LANDSAT 
requirements. A second goal was to be able to accommodate virtually any 
185