Abstract: A system for enabling communication utilizing a satellite communications network includes a mobile communication device and a satellite modem apparatus. A text message is generated at the mobile communication device and transmitted to the satellite modem apparatus using a short range wireless protocol. The satellite modem transmits the text message as a short burst data message to a satellite within the satellite communications system where it is routed to a receiver unit. The satellite modem apparatus does not include a processor. Instead, the mobile communication device includes a processor and program code for generating, transmitting, and receiving text messages, and for encrypting a text message, and/or compressing a text message to a size suitable for transmission via an L-band communications protocol from the satellite modem apparatus.

Abstract: A system for enabling communication utilizing a satellite communications network includes a mobile communication device and a satellite modem apparatus. A text message is generated at the mobile communication device and transmitted to the satellite modem apparatus using a short range wireless protocol. The satellite modem transmits the text message as a short burst data message to a satellite within the satellite communications system where it is routed to a receiver unit. The satellite modem apparatus does not include a processor. Instead, the mobile communication device includes a processor and program code for generating, transmitting, and receiving text messages, and for encrypting a text message, and/or compressing a text message to a size suitable for transmission via an L-band communications protocol from the satellite modem apparatus.

Abstract: A communication system (30) includes a transmitter (32) which generates transmit phase points (54) defined to be the vector sum of two or more QPSK signals (76, 78). Forward error correction encoding (48) is performed independently for the QPSK signals. In a receiver (34) alternate hypotheses are formed about the potential values that might have been transmitted for at least one of the QPSK signals, and offset phase points (68) are defined for each hypothesis. Each offset phase point has the effect of cancelling at least one of the two or more QPSK signals from the combined communication signal (36). Branch metrics (70) are responsive to Euclidean distances between all offset phase points (68) and all noise-free phase points that correspond to the QPSK signal about which no hypotheses are formed. A decoder (72) is configured to accept and reject the hypotheses in addition to counteracting noise.

Abstract: A TCAS receiver includes an antenna, an analog to digital converter (ADC), and a FPGA. The antenna receives an ADS-B squitter signal. The ADC converts the signal to a digital signal. The FPGA uses matched filters for matching at least a portion of the digital signal to a message, thereby increasing ADS-B squitter sensitivity.

Abstract: Embodiments of the present invention provide for an overall hardware and software approach to Mode-S demodulation, especially where the Mode-S signals (such as squitters) have been modulated with multiple modulation protocols. Various implementations utilize coherent phase detection, since coherently detecting phase transitions in a multiple modulated signal results in better sensitivity and improved interference rejection over non-coherent modulation techniques. Further, addressing the demodulation of multiply-modulated signals may also be approached in embodiments of the present invention as a unified demodulation system, rather than disjoint demodulation of the separately modulated protocols.

Abstract: Measurements of frequency and/or phase are taken at the signal ports (S1-S4) of an ISS device (10). These measurements are used to determine phase errors within the ISS device, and phase errors due to the antenna cables (C1-C4). On port, (e.g., S1) is selected as the reference port and then, based on these determined phase errors, offsetting phase errors are determined to correct the phase for the other ports (e.g., S2, S3, S4) with respect to the reference port. The signals at the antenna ports (A1-A4) are then in phase when an omnidirectional antenna pattern is desired from the TCAS antenna array (16). One in embodiment the frequency of the calibration signal is fixed; in another embodiment two different, fixed frequencies are used; and in still another embodiment the frequency is swept to achieve a predetermined measured phase difference.

Abstract: An apparatus (100) and method (300) for determining the status of a electric cable (20) is provided. The apparatus (100) rigidly includes a probe (104) having coaxial contacts (150, 152) and including a melt unit (102) configured to melt an insulating jacket (32) of the cable (20), an instrumentation unit (106) coupled to the probe (104) and housing a cable analysis circuit (186), a status display unit (188) coupled to the instrumentation unit (106), an insulated shank (108) coupled to the instrumentation unit (106), and a hotstick adapter (110) coupled to the insulated shank (108). The cable analysis circuit (186) includes a connection determination circuit (200) configured to determine if an electrical connection between the probe (104) and the cable (20) is a valid connection, and a status determination circuit (222) configured to determine the status of the cable (20) while the electrical connection is a valid connection.

Abstract: A line phase identification system and method identifies the phase of a power line at a remote unknown-phase line (160) in a three-phase power distribution network (100). The instantaneous phase of a known-phase line (150) is measured and saved each GPS second using a 1-pps time mark of a GPS receiver (660). The instantaneous phase at the unknown-phase line (160) is measured at a single GPS second using the 1-pps time mark of a GPS receiver (660) and compared to the phase measurement taken from the known-phase line (150) at the same GPS second. The differential phase between these simultaneously taken known and unknown instantaneous phases will be close to either 0, +120, or ?120 degrees, thus identifying the line phase at the line under test (160).

Abstract: A line phase identification system and method identifies the phase of a power line at a remote unknown-phase line (160) in a three-phase power distribution network (100). The instantaneous phase of a known-phase line (150) is measured and saved each GPS second using a 1-pps time mark of a GPS receiver (660). The instantaneous phase at the unknown-phase line (160) is measured at a single GPS second using the 1-pps time mark of a GPS receiver (660) and compared to the phase measurement taken from the known-phase line (150) at the same GPS second. The differential phase between these simultaneously taken known and unknown instantaneous phases will be close to either 0, +120, or −120 degrees, thus identifying the line phase at the line under test (160).

Abstract: An apparatus (100) and method (300) for determining the status of a electric cable (20) is provided. The apparatus (100) rigidly includes a probe (104) having coaxial contacts (150, 152) and including a melt unit (102) configured to melt an insulating jacket (32) of the cable (20), an instrumentation unit (106) coupled to the probe (104) and housing a cable analysis circuit (186), a status display unit (188) coupled to the instrumentation unit (106), an insulated shank (108) coupled to the instrumentation unit (106), and a hotstick adapter (110) coupled to the insulated shank (108). The cable analysis circuit (186) includes a connection determination circuit (200) configured to determine if an electrical connection between the probe (104) and the cable (20) is a valid connection, and a status determination circuit (222) configured to determine the status of the cable (20) while the electrical connection is a valid connection.

Abstract: A low tire pressure warning system includes a tire pressure sensor constructed to be mounted within each of the tires on the wheels of a vehicle. Each tire pressure sensor includes a pressure switch coupled to a transmitter and a battery, with the pressure switch being constructed to connect the battery to the transmitter so as to activate the transmitter when pressure within the tire drops below a low value. A receiver is constructed to be mounted within the vehicle in communication with the transmitters and a low tire pressure warning indicator is coupled to the receiver so as to be activated when the receiver receives a signal from any one of the transmitters.

Abstract: A signal converter (20) processes an incoming digital data stream (24) to produce an analog signal (26). A pulse shaping network (28) is configured to receive the incoming digital data stream (24) and generate a plurality of subset data streams (30). A precompensation network (32) then crosscouples the subset data streams (30) to produce crosscoupled data streams (38). Each of crosscoupled data streams (38) are then converted by respective ones of digital to analog converters (22) to produce intermediate analog signals (44). The intermediate analog signals (44) are summed by an operational amplifier (46) to produce the analog signal (26). The precompensation network (32) can be combined with the pulse shaping network (28) by using a common look-up memory element (70) to perform both functions.

Abstract: A method and apparatus for docking a motorboat including providing boat docking apparatus with a length of cable, having a weight affixed to one end, and cable retrieving apparatus, having a second end of the cable adhering thereto. The boat is moved to within the length of cable, and the weight, with one end of the cable, is propelled to the boat. The cable is attached to the boat and the motor of the boat is operated into reverse sufficient to tighten the cable while a steering mechanism is operated, against the force of the cable, to align the boat with a boat trailer. The cable retrieving apparatus is activated to retrieve the cable and pull the boat to the trailer and the boat is hoisted into the trailer in a normal fashion.

Abstract: An airborne doppler radar wind shear detection system has a volumetric scanning pattern for providing atmospheric measurement data for individual resolution cells that are formed into a 3-D grid of atmospheric data samples. Volumetric feature extraction modules identify and group resolution cells having particular features into air masses of interest. A spatial feature association and filtering module combines the air masses of interest into a 3-D representation of atmospheric conditions and filters out ground clutter. A contextual matching and temporal tracking module compares the 3-D representation to known wind shear models and compares successive 3-D representations to one another to aid in identifying hazardous wind shear conditions in the aircraft flight path.

Abstract: A PN modulated signal is applied to an end of a network electrical distribution circuit. The signal produces a snapshot trace of energy reflected from various discontinuities along the circuit, including a fault. Because the fault absorbs a large part of the energy in the applied signal, reflections from discontinuities in the same branch as the fault but farther from the input are reduced in amplitude. By knowing the position of the branches and various discontinuities, such as transformers, the position of the fault can be logically determined. If the fault is a high resistance fault a high voltage pulse is applied to the end of the circuit. The PN signal is initially sensed at a time when the fault has a low resistance because of arcing due to the high voltage pulse.

Abstract: A PN modulated signal is applied to a near end of a buried electrical cable. The signal produces an initial pulse, a second pulse of energy reflected from a fault and a third pulse representative of the far end of the cable. The time/distance between the second and third pulses is stored. As the PN signal is continuously applied an operator, using an antenna coupled monitor, walks along the cable noting the time/distance between the initial and third pulses. When this time/distance equals the stored time/distance the operator is standing over the fault. If the fault is a high resistance fault a high voltage pulse is applied to the near end of the cable. The PN signal is initially sensed at a time when the fault has a low resistance because of arcing due to the high voltage pulse. To reduce stress on the cable, the arc is initialized by a high voltage low current signal and is maintained by a low voltage high current signal.

Abstract: A phase modulating system for providing PSK modulation with minimum sidelobe generation. Phase changes, during the phase transition period, are accomplished with a minimum of carrier amplitude variation. I and Q components of the carrier system are multiplied by functions derived from the data and then combined to form a constant amplitude signal during all phases of the data signal.

Abstract: A method and apparatus for entering data in a random access memory with a fixed orientation independent of the heading vector of the carrier vehicle. The data remains positionally fixed in the memory and is addressed for readout in a manner to present a heading-up display for all vehicle heading vectors.

Abstract: A single piece electrocardiograph receiver including a pair of electrodes having pieces of spongy porous material associated therewith and mounted at opposite ends of a handle so as to be in a fixedly spaced orientation. The spongy material absorbs a conductive material, such as water, and the receiver can then be pressed against the side of an animal in a heart spanning orientation to receive the electric impulses from the heart.

Abstract: A circuit for automatic gain control of a feedback system in a time that is essentially constant regardless of the signal level includes a device for producing a signal that is representative of the output of the circuit. The signal is compared with a fixed reference to determine an error signal. The error signal is multiplied by its own time integral to obtain a control signal for a weighter that is cascaded with an amplifier to provide a controlled forward path. By this means, gain of the controlled forward path is controlled within a time that is substantially independent of signal strength.