Abstract: An imaging and quantum cryptography apparatus comprising alight-refracting optical setup (101), a light-directing optical setup (102), an imaging sensor (103) capturing light refracted from the light-refracting optical setup and directed to the imaging sensor by the light-directing optical setup and at least one of a quantum key distribution (QKD) transmitter (104) generating a QKD light signal and transmitting the QKD light signal via the light-directing optical setup and through the light-refracting optical setup and a QKD receiver (105) acquiring and decoding light signals refracted from the light-refracting optical setup and directed to the QKD receiver by the light-directing optical setup. The imaging sensor, the at least one of QKD transmitter and QKD receiver, and the alignment unit, all use the same light-directing optical setup and the same light-refracting optical setup.

Abstract: A computer implemented method of tracking a travelling vessel, comprising obtaining a list of plurality of satellites capable of detecting the vessel at location(s) along predicted path(s) of the vessel. For each of the location(s) the following is performed: (a) Predicting vessel's possible future location(s) according to estimated movement vectors derived from a movement graph generated based on historical movement path(s), a recent movement path and a current location of the vessel. (b) Estimating satellites observation windows to identify candidate observation window(s) in which the satellite(s) have visual coverage of the possible future location(s). (c) Calculating detection score for each candidate observation window according to location probability score assigned to the possible future locations and view probability score assigned to the candidate observation windows. (d) Selecting preferred observation window presenting highest detection score.