Abstract: A system for, and method of, blending (or integrating) pseudo-range or position measurements and bearing-to-transmitter measurements from an eLORAN or LORAN-C receiver and position (alternatively, pseudo ranges) and velocity (alternatively pseudo-range rate) measurements from a GPS receiver. The described system can also be integrated with additional external positioning systems. In the context of an inertial navigation system (INS) application, this combined GPS/LORAN signal can be employed to provide external positioning solutions, potentially integrated with measurements from devises such as accelerometers, gyroscopes, altimeters, etc. The system includes a GPS signal input, a LORAN signal input, preprocessors for each, and an integrator to combine the two preprocessed signals to estimate errors in the full trajectory variables.

Abstract: A system for demodulation of the Loran Data Channel transmitted over the Enhanced Loran (eLoran) system including a quadrature filter. The quadrature filter calculates the real and quadrature phase components of a received ninth pulse. The resultant components are used to obtain the angle of the ninth pulse. This angle is then compared with a set of pre-tabulated angles/symbols that are calculated using the same quadrature filter on thirty-two different simulated ninth pulses. The closest angle match gives the corresponding symbol. Such twenty-four symbols make up a single Reed Solomon encoded message. This message is then passed through a Reed Solomon decoder and the transmitted message is obtained.

Abstract: A system for demodulation of the Loran Data Channel transmitted over the Enhanced Loran (eLoran) system including a quadrature filter. The quadrature filter calculates the real and quadrature phase components of a received ninth pulse. The resultant components are used to obtain the angle of the ninth pulse. This angle is then compared with a set of pre-tabulated angles/symbols that are calculated using the same quadrature filter on thirty-two different simulated ninth pulses. The closest angle match gives the corresponding symbol. Such twenty-four symbols make up a single Reed Solomon encoded message. This message is then passed through a Reed Solomon decoder and the transmitted message is obtained.