How to Measure the Time Difference of Arrival(TDOA) between two receivers

i am trying to perform a localization using TDOA arrival between multiple sensors.TDOA values can be measure using correlation between same signal received at two sensors placed at two different positions.Here i need to model the incoming radar rectangular pulse waveform which is transmitted at certian carrier frequency .can anyone guide me through

1)How to generate a rectangular radar pulse waveaform transmitted at certain fc??

2) How to perform the correlation of the signals are received at two different receivers ??