Abstract: An RF PNT system may include LORAN stations. Each LORAN station may include a LORAN antenna, and a LORAN transmitter coupled to the LORAN antenna and configured to transmit a series of LORAN PNT RF pulses having a time spacing between adjacent LORAN PNT RF pulses. One or more of the LORAN stations may include a message embedding generator coupled to the LORAN transmitter and configured to generate message RF bursts based upon an input message, and with each message RF burst being in the time spacing between respective adjacent LORAN PNT RF pulses.

Abstract: A LORAN device may include a LORAN antenna, a LORAN receiver, an RF signal path extending between the LORAN antenna and the LORAN receiver and being subject to ambient RF interference, and an ambient RF interference canceller coupled in the RF signal path. The ambient RF interference canceller may include an ambient RF interference sensor configured to generate an estimated ambient RF interference signal based on the sensed ambient RF interference, and cancellation circuitry configured to cooperate with the ambient RF interference sensor to generate an ambient RF interference cancellation signal based upon the sensed ambient RF interference signal, and add the ambient RF interference cancellation signal to the RF signal path.

Abstract: A long range navigation system may include radio frequency (RF) transmitter stations at fixed geographical locations, each having an RF transmitter and an RF modulator coupled to the RF transmitter, and configured to generate a direct sequence spread spectrum (DSSS) RF signal being spectrally shaped so that 99% of power from the RF transmitter is within the frequency range of 90-110 KHz. Movable RF receiver units each include an RF receiver and a demodulator coupled to the RF receiver configured to demodulate the DSSS RF signal to determine a position of the movable RF receiver unit.

Abstract: An enhanced LOng RAnge Navigation (eLORAN) system may include a plurality of eLORAN transmitter stations, and at least one eLORAN receiver device. The eLORAN receiver device may include an eLORAN receive antenna, an eLORAN receiver coupled to the eLORAN receive antenna, and a controller coupled to the eLORAN receiver. The controller may be configured to cooperate with the eLORAN transmitter stations to determine an eLORAN receiver position and receiver clock error corrected from additional secondary factor (ASF) data, the ASF data based upon different geographical positions and different times for each different geographical position.

Abstract: A LORAN device may include a LORAN antenna, a LORAN receiver, an RF signal path extending between the LORAN antenna and the LORAN receiver and being subject to ambient RF interference, and an ambient RF interference canceller coupled in the RF signal path. The ambient RF interference canceller may include an ambient RF interference sensor configured to generate an estimated ambient RF interference signal based on the sensed ambient RF interference, and cancellation circuitry configured to cooperate with the ambient RF interference sensor to generate an ambient RF interference cancellation signal based upon the sensed ambient RF interference signal, and add the ambient RF interference cancellation signal to the RF signal path.

Abstract: An RF PNT system may include LORAN stations. Each LORAN station may include a LORAN antenna, and a LORAN transmitter coupled to the LORAN antenna and configured to transmit a series of LORAN PNT RF pulses having a time spacing between adjacent LORAN PNT RF pulses. One or more of the LORAN stations may include a message embedding generator coupled to the LORAN transmitter and configured to generate message RF bursts based upon an input message, and with each message RF burst being in the time spacing between respective adjacent LORAN PNT RF pulses.

Abstract: A long range navigation system may include radio frequency (RF) transmitter stations at fixed geographical locations, each having an RF transmitter and an RF modulator coupled to the RF transmitter, and configured to generate a direct sequence spread spectrum (DSSS) RF signal being spectrally shaped so that 99% of power from the RF transmitter is within the frequency range of 90-110 KHz. Movable RF receiver units each include an RF receiver and a demodulator coupled to the RF receiver configured to demodulate the DSSS RF signal to determine a position of the movable RF receiver unit.

Abstract: An enhanced LOng RAnge Navigation (eLORAN) system may include a plurality of eLORAN transmitter stations, and at least one eLORAN receiver device. The eLORAN receiver device may include an eLORAN receive antenna, an eLORAN receiver coupled to the eLORAN receive antenna, and a controller coupled to the eLORAN receiver. The controller may be configured to cooperate with the eLORAN transmitter stations to determine an eLORAN receiver position and receiver clock error corrected from additional secondary factor (ASF) data, the ASF data based upon different geographical positions and different times for each different geographical position.

Abstract: Systems (100) and methods (500) for method for providing a redundant or distinct transmission feature to a communication system (100). The methods involve (508) detecting if there is a communication system fault. If a communication system fault is detected (508:YES), then (512) a plurality of modified transmit signals are generated by combining a transmit signal with a plurality of complex weights (W1, W2, W3). The modified transmit signals are then (514) transmitted from a plurality of antenna elements (106a, 106b, 106c) of the communication system to an object of interest (108). If a communication systems fault is detected (508:NO), then (526) a plurality of redundant or distinct transmit signals are generated by combining the transmit signal with a plurality of first orthogonal or approximately orthogonal numerical sequences. The redundant or distinct transmit signals can then be (528) synchronously transmitted from the antenna elements.

Abstract: Systems and methods for operating a communications system. The methods involve computing one or more complex weights to be applied to transmit signals and receive signals by beamformers. The complex weights are based at least on configuration data for the communications system. The methods also involve applying a first plurality of weight corrections to the complex weights based on phasing errors occurring in a communication path inclusive of a control system and antenna elements. The methods further involve applying a second plurality of weight corrections to the complex weights based on phase differences at the antenna elements relative to a reference location for the receive signals.

Abstract: Systems (100) and methods (500) for method for providing a redundant or distinct transmission feature to a communication system (100). The methods involve (508) detecting if there is a communication system fault. If a communication system fault is detected (508:YES), then (512) a plurality of modified transmit signals are generated by combining a transmit signal with a plurality of complex weights (W1, W2, W3). The modified transmit signals are then (514) transmitted from a plurality of antenna elements (106a, 106b, 106c) of the communication system to an object of interest (108). If a communication systems fault is detected (508:NO), then (526) a plurality of redundant or distinct transmit signals are generated by combining the transmit signal with a plurality of first orthogonal or approximately orthogonal numerical sequences. The redundant or distinct transmit signals can then be (528) synchronously transmitted from the antenna elements.

Abstract: Methods for compensating for phase shifts of a communication signal. The methods involve determining a first reference signal (Vref-1) at a first location along a transmission path and a second reference signal (Vref-2) at a second location along the transmission path. Vref-2 is the same as Vref-1. At the first location, a first phase offset is determined using Vref-1 and a first communication signal. At the second location, a second phase offset is determined using Vref-2 and a second communication signal. A phase of a third communication signal is adjusted at the second location using the first and second phase offsets to obtain a modified communication signal. The first, second, and third communication signals are the same communication signal obtained at different locations along the transmission path.

Abstract: A system and method for model-based control of a the physical system, based on a computer simulation model approximating operating characteristics of at least a portion of the plurality of components and having one or more model parameters for adjusting a modeled operating characteristic of at least one of the plurality of components is provided. In the system and method at least one active input parameter for the physical system is generated based on current values for the model parameters and the computer simulation model and at least one measured system parameter value and at least one modeled system parameter value are obtained for measuring the performance of physical system responding to the active input parameter. The system and method also evaluate a difference between the measured system parameter value and the modeled system parameter value and update the current values for the model parameters to minimize the difference.

Abstract: Systems and methods for operating a communications system. The methods involve computing one or more complex weights to be applied to transmit signals and receive signals by beamformers. The complex weights are based at least on configuration data for the communications system. The methods also involve applying a first plurality of weight corrections to the complex weights based on phasing errors occurring in a communication path inclusive of a control system and antenna elements. The methods further involve applying a second plurality of weight corrections to the complex weights based on phase differences at the antenna elements relative to a reference location for the receive signals.

Abstract: A system for managing an assemblage of entities. The entities interface within the assemblage for control of primary information handling functions and further interface with the system to permit the carrying out of management functions. The system includes management modules adapted to carry out management functions by independently interpreting and executing commands and a kernel including a table of dispatch pointers for directing the commands to the respective modules in which they are to be interpreted and executed. In addition, the system includes storage containing domain information defining groups of entities, where the kernel may issue a command to a group by issuing individual commands to appropriate modules.

Abstract: A system for managing an assemblage of entities. The entities interface within the assemblage for control of primary information handling functions and further interface with the system to permit the carrying out of management functions. The system includes management modules adapted to carry out management functions by independently interpreting and executing commands, a kernel including a table of dispatch pointers for directing the commands to the respective modules in which they are to be interpreted and executed, and an enroller for enrolling new modules into the system by adding further pointers to the table.

Abstract: A system for managing an assemblage of entities. The entities interface within the assemblage for control of primary information handling functions and further interface with the system to permit the carrying out of management functions. The system includes management modules adapted to carry out management functions by independently interpreting and executing commands, a kernel including a table of dispatch pointers for directing the commands to the respective modules in which they are to be interpreted and executed, and an enroller for enrolling new modules into the system by adding further pointers to the table.

Abstract: In a digital data recovery receiver, an optimal (in the Maximum likelihood sense) estimate of Es/No (dB) is obtained by the following mechanism. First, over a prescribed symbol span of N symbols, for each of 2.sup.B-1 -1 quantization bins, respectively associated with 2.sup.B-1 threshold levels used by a B-bit resolution analog-to-digital converter to digitize a received signal, the number of times that the received signal is quantized with respect to that level is counted. Each count total is divided by the number N of symbols in the span, to obtain plural ratios, respectively representative of probalities of symbol pseudo error rate over the symbol span. Using these ratios, respective Es/No (dB) values are derived from stored pseudo error relationships, each of which is associated with a respective one of the 2.sup.B-1 -1 quantization bins and defines the probability of symbol error rate in terms of Es/No (dB).

Abstract: The possibility of overload (saturation-lockup) condition of an ALPC satellite communication network is avoided by a scheme that grants network entry (allocates TWT power) to each link one at a time. As each link is granted entry into the network, the corresponding TWT probability density function is computed and then integrated to obtain a TWT cumulative distribution function. The required rain margin M.sub.r for a specified availability is determined from the cumulative margin. The computed margin M.sub.r is set equal to the initial satellite TWT operating point change (multiplicative factor) MR.sub.1 due to rain fade, MF.sub.1 =M.sub.r to ensure that network stability considerations and rain fades equally constrain network performance. This result is then used to compute the value of the corresponding multiplicative factor MF.sub.2.

Abstract: To measure the figure of merit (G/T) and beam radial pointing error of a satellite earth station multiple Y-factor measurement are taken using a "drift cut" procedure and then these measurements are processed using a maximum likelihood estimate (MLE) algorithm. For carrying out the "drift cut" measurement process, the earth terminal's antenna is positioned such that the antenna beam intersects the path of the apparent star motion with a predetermined declination offset and ahead of the current star position. As the star position approaches the stationary antenna beam position, power measurements uniformly spaced in time are recorded. These power measurement "samples" are then divided by the "cold sky" power measurement to obtain corresponding Y-factor measurements. To eliminate the problem of antenna pointing error and star ephemeris error, multiple drift cuts are carried out, each offset in declination by a different amount from the estimate star declination, to produce a matrix of Y-factor values.