Abstract:
An aircraft (12) takes off from an airfield (10) along a flight path (14) until it reaches an alititude of 10,000 feet (16). The plume (20) from an IR guided missile (22) is detected by a detector (24) associated with a ground-based IR countermeasure jamming pod (26). The detector (24) activates a laser pointing control unit (34) to gimbal the head (36) to direct a laser beam (38) toward a missile (22) for jamming.
Abstract:
Techniques for multiple access differential frequency-hopped spread spectrum (MA-DFHSS) aided by multiuser detection (MUD) (640) are disclosed. An initial DFH decoding (510) is performed to provide data estimates (435) for each user (640) represented in a received co-channel signal (400) . Interference cancellation is the performed using MUD (640), thereby providing an interference-cancelled signal (540). Data estimates remaining are then re-decoded. Iteration on the interference cancellation and re-decoding can be carried out to satisfy a particular rule of iteration, although iteration is not always necessary. The final decoded signal (565) can then be provided to its destination.
Abstract:
The system in one embodiment relates to tightly integrating parameter estimation, symbol hypothesis testing, decoding, and rate identification. The present invention provides Turbo-decoding for joint signal demodulation based on an iterative decoding solution that exploits error correction codes. The system iteratively couples an initial amplitude estimator, a symbol estimator, a bank of decoders, and a joint amplitude estimator to produce the symbol estimates.
Abstract:
A nested cavity embedded loop mode antenna is provided with an ultra wide band response by nesting individual embedded cavity meander line loaded antenna modules, with the meander lines coupled to a ground plane plate either capacitively or directly so as to provide as much as a 27:1 ratio of high frequency to low frequency cutoff. The nested meander line structure is exceptionally compact and eliminates the problem of a null in the antenna radiation pattern perpendicular to the face of the antenna, thus to provide a loop type antenna pattern at all frequencies across which the antenna is to be operated. The use of the nested meander line configuration provides a flush mount for the antenna having a footprint associated with the larger of the meander line cavities and thus the lowest frequency of operation, the nesting precluding the necessity of providing separate side-by-side meander line loaded antennas which would increase the real estate required. Additionally, a shunted slotline embodiment of the cavity-embedded antenna substitutes shunted slots for meander lines to provide for a low-cost wide bandwidth cavity-embedded antenna.
Abstract:
A MUD (115) enabled cable modem (615) that provides efficient use of cable television network bandwidth in the presence of interference and noise is disclosed. The modem (615) design provides for compatibility with existing network hardware and protocols so that bandwidth efficient modems (615) configured in accordance with the principles of the present invention may be added to the network without removing installed hardware and software. A bandwidth efficient modem (615) in the cable network head-end (505) increases reverse link capacity from the terminals to the head end, while bandwidth efficient modems (615) in cable network terminals increases forward link capacity from the head end (505) to the terminals. Bidirectional bandwidth efficiency is thereby enabled.
Abstract:
A technique is provided that uses a dual mode seeker (IR and LADAR) for precise target dynamics measurement, which extends stripping to a much higher altitude than ground based radar. Initial results show that this approach works to altitudes in excess of 100 km. Stripping becomes a reliable way to discriminate lighter weight decoys from reentry vehicles at altitudes and ranges consistent with planned divert capabilities for terminal phase missile defense. It is a finding of this invention that the LADAR will improve the spatial resolution by a factor of five over typical missile defense IR seekers using a common aperture. The LADAR provides a 3D angle, angle, range (AAR) image for each laser pulse which is used to extract the precise target state vectors.
Abstract:
A method for deflecting a projectile from an initial trajectory. Such a projectile has a first surface area and a second surface area and moves through a gaseous atmosphere with a surrounding plasma sheath. This method includes the step of directing electromagnetic radiation toward the projectile, wherein the electromagnetic radiation has a wavelength which is absorbed by the plasma sheath but is not substantially absorbed by the gaseous atmosphere.
Abstract:
A stagger tuned meanderline loaded antenna is disclosed. The antenna meanderlines are configured for manipulating the antenna's current null, which enables a combination of loop mode and monopole mode current distribution. The antenna quality factor can be adjusted substantially independent of antenna gain to achieve an extended Chu-Harrington relation.
Abstract:
A wideband double monopole meanderline loaded antenna having a single feed (110) through a vertical radiator (102), horizontal radiators (104) and vertical supports (114) connected to a ground place (112) is disclosed. Equalizing delay lines (108a, 108b) of the antenna can be manipulated to equalize reactance of the antenna thereby enabling proper impedance matching.
Abstract:
A method of detecting and determining the bearing of a rocket launch or muzzle blast. First a plurality of spaced electrical field sensors (Figure 8) is provided. Then distortions of the electrical field at each of said sensors are measured (Figures 5a-5c).