  The Maier-Leibniz Doppler-Shift technique is the most popular and accurate
technique used in fission experiments to separate the yield of gamma rays from
each of the two fission fragments. The technique exploits the aberration, i.e.,
the change in the angular distribution, of gamma rays emitted by a moving
source. By measuring the speed and direction of the source with a conventional
detector, as well as the yield of gamma rays at several angles from the
direction of motion, the technique can be used to determine the mean
multiplicities of gamma rays from each fragment. We show in this work that it
is possible to extend the technique to also measure second moments of the gamma
ray radiation from each fragment. In particular, given the current interest in
fragment correlations in fission, we show that the covariance of the emission
between the two fragments can be inferred. Experimental limitations and
convergence of the new technique are discussed.
