Perform frequency analysis on grouped pulses
The first step is to low pass filter the signal with 100Hz cutoff and then resample everything at 200Hz. This doesn't change the spectrum in the 0-100Hz range. Therefore, it's not possible to gain anything of use from the faster signals.

The 0-100Hz spectrum will be the same as if there were a single 45-450μs pulse occuring at 10Hz. There will peaks at multiples of 10Hz (harmonics) and the maximum will be the 10Hz peak itself.