| Sensor | Blind spot | How an opponent uses it |
|---|---|---|
| Optical | Night, cloud, between two passes | Activity at night or under cloud; covering up just before a known pass |
| Infrared | Little contrast at equal temperatures | Cold storage, heat-reducing nets |
| SAR | Hard to interpret; metal decoys | Inflatable or metal dummy vehicles, corner reflectors |
| SIGINT | Sees nothing that does not transmit | Radio silence (EMCON), cable links, short transmissions |
| All | A satellite in LEO is not a camera that watches constantly | Calculating pass times and planning around them |
Key point
That is why analysts combine sensors: SAR for "is something there", optical for "what is it", SIGINT for "is it transmitting", and repeated images for "is it changing". No single satellite gives the whole picture on its own.