What pulse starts the range sweep in a range-gate generator?

The range sweep in a range-gate generator is initiated by the transmitter pulse. This pulse signifies the beginning of a signal transmission and establishes the timing for the entire range-sweep process. When the transmitter pulse is sent out, it triggers the range-gate generator to begin its operation, allowing it to accurately measure and process the return signals from targets.

The other options, while related to the overall operation, do not specifically initiate the range sweep. Receiver pulses are typically related to processing incoming signals rather than setting the timing for a range sweep. Reference pulses serve to calibrate or stabilize certain parameters within the system, and control pulses usually manage specific functions or settings, but they do not trigger the range sweep process directly like the transmitter pulse does. By starting the range sweep with the transmitter pulse, the system ensures that timing is synchronized with the transmission of the signal for effective range determination.