System and method for unmanned aerial signal relay

Abstract

An unmanned aerial signal relay includes an unmanned aerial vehicle, including a communication relay unit and at least one antenna, communicatively connected to the communication relay unit; a tether comprising at least two wires and at least one fiber optic cable, the wires and cable communicatively connected to the unmanned aerial vehicle; and a surface support system comprising a spool physically connected to the tether and a ground-based receiver communicatively connected to the at least one fiber optic cable, wherein the unmanned aerial vehicle is powered by electrical energy provided by the at least two wires, and wherein the communication relay unit is configured to relay signals received from the at least one antenna via the fiber optic cable to the ground-based receiver. Various systems and methods related to an unmanned aerial signal relay are also described.

1 - 24 . (canceled) 
     
     
         25 . A method of calculating the position of a tethered, unmanned aerial vehicle, comprising the steps of:
 measuring a gimbal orientation from a gimbal positioned substantially centrally to an unmanned aerial vehicle airframe, the gimbal physically attached to the unmanned aerial vehicle and a tether connected to a ground unit;   measuring an aircraft altitude from an altitude sensor or a pressure sensor;   acquiring a ground unit position from a position sensor on the ground unit;   calculating an approximate tether vector from the altitude and gimbal orientation; and   calculating the approximate position of the tethered unmanned aerial vehicle to the ground unit by adding the approximate tether vector to the ground unit position.   
     
     
         26 . The method of  claim 25 , further comprising:
 measuring the aircraft attitude from an attitude sensor; and   calculating the approximate tether vector further based on the attitude.   
     
     
         27 . The method of  claim 25 , wherein the attitude sensor is an inertial navigation unit. 
     
     
         28 . The method of  claim 25 , further comprising:
 obtaining a first barometric pressure measurement from a first barometric pressure sensor physically connected to the unmanned aerial vehicle;   obtaining a second barometric pressure measurement from a second barometric pressure sensor physically connected to a ground unit positioned on the opposite end of a tether, the tether physically connected to the unmanned aerial vehicle; and   calculating the altitude based on the difference between the first and second barometric pressure measurements.   
     
     
         29 - 35 . (canceled)