Right after finishing the previous video about radar resolution, I stumbled upon something amusing and unexpected: a KLJ-7’s “phantom” radar mode.
VS stands for Velocity Search. For the RIOs among you, it is somewhat similar to Pulse Doppler Search. No ranging information is provided, only closure rate, or V-sub-C. In the JF-17, bugging a radar return whilst the radar is in VS mode switches to STT, or Single-Target Tracking. There is no “soft lock”, so to speak. Or so it seems.
As it turns out, I managed to enter a whole new radar mode starting from VS. This mode shows target information, such as range, V-sub-C and aspect, and even the HAFU. Even other contacts are shown, with the caveat that the displayed information is in Azimuth versus V-sub-C rather than versus Range, as b-scopes do. I admit this is my wet dream as a Tomcat RIO. If only our DDD could do that!
Anyway, after labelling the new mode VSTTWS, or “Velocity Single-Target-Track While Search”, I wondered whether this was a “hard lock” or a “soft lock”. Answering the question is trivial by taking advantage of the AI. Non-human aircraft, in fact, toggle their ECM as soon as a “hard lock” is established. As you can see, this funny-looking radar mode is a mix of the two: it starts as an STT, but then the lock is broken by the target when its noise jammer is activated. However, the lock is not lost: it is still there, strong and reliable. Long story short, every couple of seconds the radar automatically reacquires the target.
So, given this behaviour, the lock is definitely an STT-type.
At this point, I could not resist the temptation to engage a jamming target as I did a couple of years ago with the Tomcat. The target uses a sort of blinking noise jammer, albeit at an abnormally low frequency. Will the SD-10 manage to reach our target? Let’s see.
Our guinea pigs are a pair of Tomcats. Let’s focus on one of them. Thanks to VS, we spot them beyond 50 nm. Then, I immediately entered the funny-looking radar mode, pulled up and fired. I wanted to launch before 50 nm, but between the views and the pull I lost a few seconds.
If you are wondering why I launched two SD-10s, it is because the unstable attitude annoys the hell out of me.
The aircraft spawned at circa 26,000 ft. Despite the range and the kind-of low altitude, the SD-10s travelled fast and splashed the target.
So, to wrap this up, the “VSTTWS” mode is probably a simple bug, perhaps a leftover. I have found no trace of this mode in the manual. Besides, a Velocity Search-type mode capable of providing the complete set of information we have seen, makes little sense.
What do you think, folks?
FlyAndWire 