At first I thought it was a Mig I-320, but the landing gear isn't right.
Maybe a Yak-30 with a experimental radar installation ?
Or something in front of a Yak-30, that has no connection to it ?
It looks too big to be a pitot tube.
Maybe you have some suicidal Soviets there, if that's a cannon barrel.
That location for a cannon didn't work too well on a Mig-9, did it ?