The reflectometer is able to measure in 20 ps steps (or any other step, it is just a matter of software configuration). The pulse generator makes rectangular wave with risetime of 85 ps. Measured risetime is about 200 ps. As a standalone device, it can detect simple discontinuities, such as shorts, disconnected cable, a split which halves impedance. When connected to PC, it can perform OSL calibration and show calibrated data.
If you want to know more, look into project logs.