Looking at source materials, it is not hard to see what they are doing. They have radome’s to obfuscate where their dishes are pointed, and use them to collect

Looking at source materials, it is not hard to see what they are doing. They have radome’s to obfuscate where their dishes are pointed, and use them to collect signals that pass through the Chinese and other satellites they can see. They appear to request processing assistance from NSA, so the most educated guess would be that they know the right satellites to collect from, but are not quite there yet in terms of normalizing and analyzing most of the data. You can scroll to the bottom of linked article to view the source documents.