Remember the MiG-25 was developed to intercept the Mach 3 US bomber valkyrie, and when that aircraft was cancelled it was adapted to the recon role and interception of other mach 3 types.
But: 120 miles with an IRST?? They are about 200-240 kM: isn't there the horizon curvature??
SR-71 can't fly very fast at low level and only ever flew operationally at altitudes above 15km altitude.
Apart from the sun there are few other IR emitting objects at such altitudes and the cold air and lack of moisture to absorb IR radiation means long detection ranges for hot objects.
From the USSR, which kind of radar used they for the detection in Turkey? Over-the-horizon radar, or satellite?
Can't say for sure, but both China and Vietnam were also able to detect and track the SR-71 soon after takeoff to landing... it has a steep climb and operates at a high altitude which makes its flight profile fairly distinctive.
Last edited by GarryB on Fri Nov 28, 2014 10:51 pm; edited 1 time in total