Even countries that do not experience a level of crustal deformation that challenges a national datums internal integrity regard permanent GPS CORS networks to be important infrastructure that supports national (and international) geodetic and geoscientific studies.
However, the inter-receiver spacing was rarely less than a hundred kilometres, and often it was much more. Furthermore, all such infrastructure until relatively recently did not have a real-time data transfer or processing capability.
In the 1990s, when the establishment of such CORS networks was justified on geodetic grounds, national networks
were similar to IGS stations.
That is, although operated on a “24/7 basis”, the data were only periodically downloaded
from each receiver as ASCII files in the Receiver Independent Exchange (RINEX) format,
and sent to an archive or data centre. From there the data were available to users for postprocessing.