| 摘要 |
FIELD: physics, communication. ^ SUBSTANCE: invention concerns methods of detection of infringement of working capacity of the protected fiber-optical systems of transmission (FOTS) information of restricted access and can be used as an expedient of the constant control of a fiber-optical transmission line (FOTL) from leakage on the optical channel. In the method, consisting in reception, detection of optical signals from a fiber-optical line, amplification, integration and analogue-digital transformation of the gained analogue electrical signals which in the numeral shape are compared to control value in such a manner that in case of decrease in amplitude of a signal below control value on the given quantity the alarm signal is shaped. That through each quantity of readout N making a j-th cycle set by the timer, medial sampling value which is calculated is new the gained quantity Faugh is remembered and used in the subsequent cycles for evaluation of a control signal under the formula after the termination of each j cycles remembered and subtracted from the value calculated in the j-7, j-k1, j-k2...j-km cycles, the gained difference is compared to in advance given thresholds of detection Phid and alarms Phia and in case one of requirements that is carried out the alarm signal is shaped, in a case if one of requirements that for quantity of medial sampling value in a j+1 cycle is carried out quantity calculated either in j-k1-1, or in j-k2-1 is accepted, either in j-k3-7 or ... in j-km - depending on what of requirements (4) is carried out, otherwise the value is accepted, used in y cycle, and k1/k2, k12/k...km-1/km>=Phia/Phid. ^ EFFECT: increase of the signal/noise relation at decision-making for signals pickup of any shape, amplitude and duration, and also an error exception at decision-making at the expense of the account of slow changes of a signal in definition of control value. ^ 1 dwg |
