METHOD OF MONITORING STATE OF UNDERGROUND METROPOLITAN STRUCTURES AND SYSTEM FOR REALISING SAID METHOD Russian patent published in 2011 - IPC G01S13/75 

FIELD: physics.

SUBSTANCE: system for monitoring the state of underground metropolitan structures has electronic identifiers l.i(i=1,2,…n), a reader 2, a transmitting wireless modem 3, with a transceiving antenna 8, a receiving wireless modem 5 with a receiving antenna 23, connected to a computer 4. The electronic identifier l.i(i=1,2,…n) contains a piezoelectric crystal 18, a microstrip antenna 19, electrodes 20, buses 21.1 and 21.2, a set of reflectors 22.1 and a detecting element 22.2. The reader 2 contains a driving generator 6, a circulator 7, a high frequency amplifier 9, a phase detector 10, a phase doubler 30, a phase halver 31 and a narrow band-pass filter 32. The transmitting modem 3 contains delay lines 11 and 40, a pseudorandom sequence generator 12, an adder 13, a multiplier 14, a narrow band-pass filter 15, a phase manipulator 16, a power amplifier 17, a phase metre 33, an analogue-to-digital converter 34, a unit for generating reference phase shift 35, a code comparator 36, switches 37, 38 and 39, a memory unit 41 and a switch 42. The receiving wireless modem 5 has a computer 4, a high frequency amplifier 24, multipliers 26 and 27, a narrow band-pass filter 28 and a low-pass filter 29. Multipliers 26 and 27, low-pass filter 29 and narrow band-pass filter 28 form a phase-shift keyed signal demodulator 25.

EFFECT: high reliability.

2 cl, 5 dwg