If the 'Full Frame' body was using a 24-70/2.8 lens and the 'APS-C' body was using a 16-50/2.8 lens, they would both be capable of almost identical images, but with an aperture of f/2.8 and a subject distance of 7 feet, the 'Full Frame' body would have a DoF of 0.5 feet and the 'APS-C' body would have a DoF of 0.66 feet, about what the 'Full Frame' ...
A Double Pole Double Throw (DPDT) switch is a switch that has 2 inputs and 4 outputs; each input has 2 corresponding outputs that it can connect to. Each of the terminals of a double pole double switch can either be in 1 of 2 positions. This makes the the double pole double switch a very versatile switch. With 2 inputs, it can connect to 4 different outputs or reroute a circuit into 4 different modes of operation. A Double Pole Single Switch is actually two single pole double (SPDT) switches.
Differential phase shift keying (DPSK) is a common form of phase modulation that conveys data by changing the phase of the carrier wave. As mentioned for BPSK and QPSK there is an ambiguity of phase if the constellation is rotated by some effect in the communications channel through which the signal passes.