Return to IBM SAGE
Les Earnst has said for years that SAGE was useless against jamming, ECM (Electronic Counter Measures) but he was/is never specific. At considerable risk from his abrasive tongue and inflammatory accusations, we had exchanged about 5 e-mails. Several people dropped out of the dialog not wishing to listen to his hostile name-calling.
HOWEVER, Les may have a point !! - which he doesn't state, I'm only guessing, or placing words in his mouth.
Apparently the acquisition/surveillance radar output unit to provide input to the SAGE computer was a robot (of unspecified characteristics - Les might not know) rather than a human that could use techniques, skills, and training to reduce the effectiveness of jamming.
Active jamming can make the actual targets much harder to see than in the above image. (Pictures of passive (chaff and other reflective devices) and active jamming are hard to obtain). Working against jamming is much like driving into the setting sun - difficult, no fun, counter jamming equipment, technique and training are helpful.
A PPI (Plan Position Indicator) display with planes and likely some jamming The ground clutter (in the middle) could have been largely eliminated my MTI (Moving Target Indicator) circuits which compare this pulse return with the return of the last pulse
The three large blobs to the up side (usually north) could be the start of chaff drops. The long tailed "comets" are moving planes - the persistence of the phosphor (fades completely in maybe 2 minutes)
(Photo credit Rolf Goerigk)
So, how would you construct or program a robot to handle video such as the above, or much worse !! Jamming can make a real mess - tough to see the real target(s) - training and practice can help a lot, jamming resisting equipment and adjustments are available -
As messy as the above image is, it does not contain the results of IFF (Identification Friend or Foe) which results from transponders mounted on friendly planes which respond to secret coded pulses streams (on a different frequency) sent out at the same time as the acquisition radar pulses. The IFF responses are (usually) painted on this same display as short arcs of secret patterns just beyond the responding (friendly) aircraft. The IFF challenges are usually not transmitted unless required for a number of reasons.
To try handle cases where the IFF transponder in the friendly aircraft is not working, such as shot up, the aircraft could be asked to fly in a directed pattern (turn left, turn right, ...) or use safe secret flight corridor(s).
As you might imagine, operating acquisition radars against multiple aircraft, using active and/or passive jamming can be "interesting", a skill beyond the ability of any device interpreting the video signals and supplying information to systems such as SAGE. It is tough enough for trained, adaptable, humans using various techniques to reduce the effects of jamming.
Note also: multiple aircraft keep human (and/or robot) very busy. Is there some assurance that all of the detected "targets" are tracked and fed into the SAGE system. Just missing one, carrying a nuclear warhead, will cause you to lose "the game", ruin your whole day.
The above is the barest introduction to a complex, sophisticated, heavily studied, active, important field of activity. Important words/concepts commonly used in the field are not even mentioned.
Executive Conclusion ;-)
If in fact SAGE depended upon non-human "robots" to interpret the radar returns, SAGE may well have been relatively useless against jamming techniques.
Your comments are solicited - Ed Thelen firstname.lastname@example.org