Abstract: A radiometer and a method for indicating water content and water content change caused by water and/or liquid water are disclosed. According to the method, changes of noise temperature values are observed by receiving microwave electromagnetic radiation at a medium frequency. This medium frequency is considerably below the lowest absorption resonance (approximately 22 GHz) of water molecules. At least one noise temperature value is set as reference value, and noise temperature changes are compared with the reference level.

Abstract: The present invention relates to a device at an antenna for eliminating grid lobes in the radar cross section of the antenna.The invention displaces the grid lobes to a frequency range outside the working frequency of the antenna by inserting rows of dummy elements (r.sub.3, r.sub.4, r.sub.5) between rows of ordinary antenna elements (r.sub.1, r.sub.2) in the antenna (11). The dummy elements will behave like the ordinary antenna elements (15) as regards the rescattering when the dummy elements (17) are irradiated with signals from outside. Furthermore, the dummy elements (17) are not fed by a feeding network (16a, 16b) with microwave signals as is the case with the ordinary antenna elements (15). The dummy elements (17) are arranged in the rows of dummy elements (r.sub.3, r.sub.4, r.sub.5) so that the distances in X-direction and in Y-direction (a.sub.4, a.sub.5, a.sub.6, a.sub.7, a.sub.

Abstract: A method and an apparatus for a multibeam phased array antenna transmission based on heterodyning to produce the RF transmission signals with appropriate phase shift and thereby reducing the effect of certain space constraints in the confined area of the transmitter as higher and higher frequencies of transmission are employed. In the present invention, RF signals at an intermediate frequency, not the ultimate frequency of transmission, comprise the signal frequencies of a beam forming network which provides input to a multiplexed power divider. The power divider outputs the phase shifted signals to an input at each of a number of multiplexed combiners. The output of each combiner is fed to a mixing device which then shifts the input frequency to a higher frequency, using an appropriate local oscillator signal. The mixer outputs are coupled to separate power amplifiers, whose outputs are fed to the elemental radiators.

Abstract: There is disclosed a method and apparatus for verifying the integrity of a smart antenna system. A signal simulator replicates the respective signals received at the multiple sensors of the antenna array, with signal parameters that include the correlated effects of Doppler, delay and angular spread. A combination of hardware and software capabilities simulate a primary line-of-sight signal, plus reflected signals and refracted signals, which requires manipulation by the smart antenna processor to extract the temporal and spatial information of the signals of interest. The simulated signals may be varied in numbers, amplitude, phase, delay and bearing components for representing a variety of terrain, environmental, equipment and capacity conditions encountered in alternative environments and conditions. The output of the smart antenna processor is checked against the input parameters to compare, verify and calibrate the smart antenna system.

Abstract: A method for determining an improved position fix by performing postprocessing on a realtime differentially corrected GPS position. A remote rover unit containing a GPS receiver is used to determine a differentially corrected position according to measured pseudoranges and realtime pseudorange correction vectors is broadcast by a base station. The rover unit applies realtime corrections to measurements to determine a more accurate realtime differential position. It then stores the realtime differential position and the realtime pseudorange correction vector. Subsequently, postprocessing is performed to determine a postprocessed pseudorange correction vector. A difference vector representing the difference between the realtime pseudorange correction vector and the postprocessed pseudorange correction vector is then determined. This difference vector is applied to the realtime differential position to calculate a more accurate, improved position fix.

Abstract: A dual global positioning system (GPS) receiver navigation system. The system of the present invention includes a primary GPS receiver adapted to determine a first position. The primary GPS receiver is certified to a first integrity level and is further adapted to provide GPS navigation data to an external device. The system of the present invention also includes a secondary GPS receiver coupled to the primary GPS receiver. The secondary GPS receiver is certified to a second integrity level having less stringent requirements than the first integrity level. The secondary GPS receiver is adapted to determine a second position and monitor the primary GPS receiver to detect a fault condition by comparing the first position and the second position, such that the GPS navigation data is provided in accordance with the first certification level regardless of the second integrity level of the secondary GPS receiver.

Abstract: A global navigation satellite system (GNSS) receiver for use in an aircraft is disclosed. The GNSS receiver includes receiver circuitry for receiving satellite signals containing satellite data from a multiple GNSS satellites. The receiver circuitry generates a first navigation solution for the aircraft as function of the satellite data. A first GNSS receiver output couples to an inertial reference system (IRS) and provides the satellite data to the IRS. The IRS generates a second navigation solution for the aircraft as a function of the satellite data and as a function of IRS position data. A first GNSS receiver input couples to the IRS and receives the second navigation solution from the IRS. The GNSS receiver provides at a second output aircraft position information as a function of the second navigation solution.

Abstract: A method and apparatus for determining whether a wireless station is operating within a prescribed geographic location. During an initialization process, the wireless telephone measures propagation delays of pilot signals from nearby base stations and stores the propagation delays in a non-volatile memory of the wireless station. Thereafter, during a check process, the wireless station measures propagation delays of pilot signals from nearby base stations and compares them with the stored propagation delays stored in memory. If the difference between the two sets of propagation delays are within a predetermined tolerance, then a determination is made that the wireless station is operating within the prescribed geographic location. Multiple sets of propagation delays may be stored in memory such that a determination can be made as to whether the mobile station is operating within any one of a number of prescribed geographic locations.

Abstract: As an utility conveyance (12), such as a pipe or cable is buried, its location is accurately determined by a Global Positioning Satellite (GPS) Reading device (32) at the initial point of burial, and preferably, at successive lengths of the conveyance. A data logger (34) records the GPS location coordinates, as well as length measurement of the conveyance, to provide a permanent record of the location of the conveyance that is not require reference to any physical landmarks to enable re-location.

Abstract: A GPS navigation receiver channel tracks satellites' Doppler frequencies sequentially during the twenty milliseconds that the signal is coherent in each bit time of the navigation data modulation. It measures frequency by differencing the angles of signal-vector sums weighted by parabolic humps, exploiting the commutativity of linear processing operations to raise the signal-to-noise ratio before the nonlinear operation phase of detection.