High resolution time domain reflectometry (TDR) in fault location measurement in a cable network

A method for providing a time domain reflectometry (TDR) in a fault location measurement in a cable television (CATV) network, comprising:

• transmitting, by a processor of a test instrument, a first TDR waveform having frequency-chirped probe pulses into a test point of the CATV network, wherein the frequency-chirped probe pulses are formed by an oscillatory signal that oscillates at a varying oscillation frequency to form a width of each pulse, and wherein, during the width of each pulse, the varying oscillation frequency of the oscillatory signal increases from a minimum frequency to a maximum frequency of a frequency band;
• monitoring, by the processor, to receive a first return signal of the frequency-chirped probe pulses;
• using, by the processor, the first return signal to identify impedance changes at a fault location in the CATV network;
• performing, by the processor, a first fault location measurement by transmitting the frequency-chirped probe pulses at a first sampling rate into the test point of the CATV network;
• performing, by the processor, a first calibration measurement by transmitting the frequency-chirped probe pulses at the first sampling rate into a closed calibration circuit within the test instrument;
• and
• performing, by the processor, a second fault location measurement at a second sampling rate and a second calibration measurement at the second sampling rate that is higher than the first sampling rate.

A non-transitory computer-readable storage medium storing instructions that, when executed by a processor of a test instrument, cause the processor to:

• transmit a first time domain reflectometry (TDR) waveform having frequency-chirped probe pulses into a test point of a cable television (CATV) network, wherein the frequency-chirped probe pulses are formed by an oscillatory signal that oscillates at a varying oscillation frequency to form a width of each pulse, and wherein, during the width of each pulse, the varying oscillation frequency of the oscillatory signal increases from a minimum frequency to a maximum frequency of a frequency band;
• monitor to receive a first return signal of the frequency-chirped probe pulses;
• use the first return signal in a TDR technique to identify impedance changes at a fault location in the CATV network;
• perform a first fault location measurement by transmitting the frequency-chirped probe pulses at a first sampling rate into the test point of the CATV network;
• perform a first calibration measurement by transmitting the frequency-chirped probe pulses at the first sampling rate into a closed calibration circuit within the test instrument;
• and
• perform a second fault location measurement at a second sampling rate and a second calibration measurement at the second sampling rate that is higher than the first sampling rate.