摘要:
The present disclosure provides systems and methods associated with an antenna system comprising a tension member configured to be towed by an aerial platform. In some embodiments, a first end of the tension member may be secured to the aerial platform and the second end may extend unsecured from the aerial platform at a different elevation than the first end. A plurality of antenna assemblies, each comprising at least one antenna, may be secured to and spaced along the length of the tension member. Each of the plurality of antennas may be adapted for use with a particular frequency or frequency bandwidth. For example, each of the plurality of antennas may be adapted or tuned for one or more frequencies useful for synthetic aperture radar (SAR). In some embodiments, a receiving system, a communication link, and/or an antenna location system may be utilized.
摘要:
A towable antenna system is deployable and retrievable from and tetherable to an underwater vehicle while the underwater vehicle is submerged under water. An underwater vehicle having a towable antenna system is capable of communicating with one or more remote communication systems, the towable antenna system acting as an intermediary for communications between a submerged underwater vehicle and the one or more remote communication systems.
摘要:
An airborne electromagnetic prospecting system (10) is disclosed. The system (10) comprises a transmitter loop structure (12) hat is attached to, and arranged to be towed by, a helicopter (14). A transmitter (22) is fitted to the transmitter loop structure (12) for transmitting a primary electromagnetic field. A high drag bird (26) is attached to, and arranged to be towed by, the transmitter loop structure (12). A receiver (38) is fitted to the high drag bird (26) for receiving a primary and secondary resulting electromagnetic field, the secondary field arising from the interaction of the primary field with ground conductors that are traversed by the helicopter (14). Significantly, the high drag bird (26) is also attached to, and arranged to be towed by, the helicopter (14), so as to keep the position of the receiver (38) relative to the transmitter (22) substantially constant.
摘要:
A fast deployment and retrieval system permits the rapid deployment of a decoy in seconds in response to an incoming threat, thus eliminating the necessity of pre-deployment, with retrieval permitting reeling in and deployment of the decoy a number of times during a mission in response to threats, and a commensurate reduction in life cycle cost. Upon detection of an incoming threat by a warning receiver, a controller coupled to a transmission releases a brake that is utilized to control the speed of deployment, whereas upon retrieval, the transmission drives a motor for retrieval of the decoy. The system is thus reusable, fast reacting, and also minimizes range penalty considerations because the decoy is only deployed when needed. In one embodiment, the system accommodates both a towing cable and a fiber-optic signal cable in which apparatus for unwinding of the cables is mechanically ganged together so that the cables pay out at the same rate. This type of payout lowers the stress on the fragile fiber-optic cable making possible multiple deployments and retrievals in response to separate threats during a mission. In another embodiment, a single, structural member with embedded conductors is utilized to connect the towed device to the round assembly.
摘要:
In a far field monitor apparatus, each of first and second ILS localizers includes a receiving antenna, a plurality of couplers, a combiner, a receiver, and a first detector. The receiving antenna is formed from a plurality of antenna elements symmetrically arranged in a direction perpendicular to the longitudinal direction of a runway. The receiving antennas of the first and second ILS localizers oppose each other. The couplers are arranged in units of antenna elements to pick up some of signals obtained by the antenna elements in a predetermined amplitude and phase. The combiner combines output signals from the couplers. The receiver receives a combined signal output from the combiner. The first detector detects, on the basis of a receiving signal output from the receiver, a predetermined monitor parameter representing the radiation state of a radio wave radiated from the opposing-side ILS localizer.
摘要:
A sphere and cable deployer apparatus for deploying a cable and associated sphere from a vehicle such as a satellite. The sphere and cable deployer apparatus has a drum for storing the cable that is driven by a drive shaft and gears form a drive motor to deploy the cable/sphere away. The drive motor also drives a drive roller through a series of gears and clutches that applies tension to the cable as it is being unwound from the drum. The sphere and cable deployer apparatus also has a sphere housing with two shell-like halves that pivot outward due to spring forces to release the sphere. The pivoting housing halves also provide a storage compartment for a short cable that is attached to the outer surface of the sphere. The pivoting housing halves are held in place by two cables that are under tension and associated pins that fit in holes in the housing halves and are released by cable cutters that cut the cables.
摘要:
In a system for launching RF energy as a traveling surface wave onto a single wire transmission line and causing such energy to be radiated away from the line at a downstream location, a series of window radiators of annular shape are spaced along the line, coaxial therewith, each for radiating a portion of the surface wave energy. Each radiator has a conductive component that causes decoupling and radiation of a portion of the RF energy, and a dielectric window that allows the remaining portion of RF energy to pass therethrough and continue, as an attached surface wave, downstream to a succeeding, similarly formed radiator where the decoupling and partial radiation occurs again. Thus, from the same surface wave transmission line system, it is possible to radiate RF energy from two or more discrete locations along the line.
摘要:
A trailing wire antenna coupling and control method for providing maximum voltage limited power output from power amplifiers of a high power low frequency RF transmitter system while varying the inductance of the coupling circuit to present a high resistance load having practically zero reactance to the power amplifiers, all during extension and retraction of the antenna toward and from its optimum length, as well as at the optimum length.