| 摘要 |
PCT No. PCT/US97/05299 Sec. 371 Date Dec. 18, 1998 Sec. 102(e) Date Dec. 18, 1998 PCT Filed Apr. 1, 1997 PCT Pub. No. WO97/39360 PCT Pub. Date Oct. 23, 1997To measure relatively long time intervals with very high resolution, apparatus and method operate to receive a first pulse and a clock signal that has a known period, synchronize the first pulse with the clock signal, stretch the first synchronized pulse in accordance with a first stretch ratio, produce a first compared output pulse corresponding to the first stretched signal, synchronize the first compared output pulse with the clock signal, generate a first pulse sequence from the first synchronized pulse and the first synchronized compared output pulse, convert times of occurrences of the edges of the first pulse sequence to respective time values, receive a second pulse and generate a second pulse sequence in a manner similar to that of the first pulse sequence, convert times of occurrences of the edges of the second pulse sequence to respective time values, count the elapsed number of clock periods between the first and second synchronized pulses, derive the time interval between the received pulses from the time values, the first and second stretch ratios, the period of the clock and the elapsed number of clock periods, and calibrate the first and second stretch ratios from the time values.
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