Abstract: Methods and systems to detect navigation signals, including to identify up to multiple range-Doppler hypotheses from each of j range-Doppler correlation grids based on a relatively low first threshold, generate navigation solutions from combinatorial sets of k of the identified hypotheses, evaluate the navigation solutions to identify plausible solutions, iteratively and combinatorially augment the plausible solutions with additional hypotheses from grids that are not represented in the corresponding k-hypotheses based navigation solutions, replace plausible solutions with corresponding augmented plausible solutions when appropriate, and select one of a plurality of plausible solutions as a best plausible solution, j and k being positive integers. Where a grid energy peak exceeds a second threshold, a corresponding hypothesis may be identified as a sole hypothesis for the corresponding navigation signal. The relatively low first threshold permits detection of weaker signals.

Abstract: Methods and systems to detect navigation signals, including to identify up to multiple range-Doppler hypotheses from each of j range-Doppler correlation grids based on a relatively low first threshold, generate navigation solutions from combinatorial sets of k of the identified hypotheses, evaluate the navigation solutions to identify plausible solutions, iteratively and combinatorially augment the plausible solutions with additional hypotheses from grids that are not represented in the corresponding k-hypotheses-based navigation solutions, replace plausible solutions with corresponding augmented plausible solutions when appropriate, and select one of a plurality of plausible solutions as a best plausible solution. Where a grid energy peak exceeds a second threshold, a corresponding hypothesis may be identified as a sole hypothesis for the corresponding navigation signal. The relatively low first threshold permits detection of weaker signals.

Abstract: A receiving station tracking system for receiving GPS data and tracking a mobile vehicle. The receiving station tracking system includes at least one processing stage receiving and processing at least a portion of the GPS data, and a control module receiving and filtering the processed GPS data and outputting at least one control signal in accordance with filtering results. The at least one control signal controls decreasing or increasing a quantity of processing stages of the at least one processing stage.

Abstract: Disclosed is a system and method for increasing the weak signal recovery capability of a Global Positioning System (GPS) receiver correlating each of the plurality of digital signals by multiplying the I and Q phases by the carrier and code, adding a location offset, accumulating the results of the correlation, and latching the results until a predetermined time; coherent combining the accumulated results at the predetermined time; non-coherent combining the coherent combined results for a time period sufficient to raise a correlation peak to a predetermined point above a noise floor to produce a plurality of non-coherent bin observables; determining a maximum value of the plurality of bin observables and comparing the maximum value to predetermined threshold; determining grid locations of bin observables having maximum values greater than the predetermined threshold; determining a bi-quadratic surface using the grid locations; determining an argument maximum of the bi-quadratic surface; estimating epoch pseu

Abstract: A receiving station tracking system for receiving GPS data and tracking a mobile vehicle. The receiving station tracking system includes at least one processing stage receiving and processing at least a portion of the GPS data, and a control module receiving and filtering the processed GPS data and outputting at least one control signal in accordance with filtering results. The at least one control signal controls decreasing or increasing a quantity of processing stages of the at least one processing stage.

Abstract: Disclosed is a system and method for increasing the weak signal recovery capability of a Global Positioning System (GPS) receiver correlating each of the plurality of digital signals by multiplying the I and Q phases by the carrier and code, adding a location offset, accumulating the results of the correlation, and latching the results until a predetermined time; coherent combining the accumulated results at the predetermined time; non-coherent combining the coherent combined results for a time period sufficient to raise a correlation peak to a predetermined point above a noise floor to produce a plurality of non-coherent bin observables; determining a maximum value of the plurality of bin observables and comparing the maximum value to predetermined threshold; determining grid locations of bin observables having maximum values greater than the predetermined threshold; determining a bi-quadratic surface using the grid locations; determining an argument maximum of the bi-quadratic surface; estimating epoch pseu

Abstract: An autonomous navigation system for an orbital platform incorporating a global positioning system based navigation device optimized for low-Earth orbit and medium-Earth orbit applications including a 12-channel, GPS tracking application-specific integrated circuit operating in concert with a microprocessor implementing an extended Kalman filter and orbit propagator which autonomously generates estimates of position, velocity, and time to enable planing, prediction and execution of event-based commanding of mission operations.

Abstract: An autonomous navigation system for an orbital platform incorporating a global positioning system based navigation device optimized for low-Earth orbit and medium-Earth orbit applications including a 12 channel, GPS tracking application-specific integrated circuit (15) operating in concert with a computer system (90) implementing an extended Kalman filter and orbit propagator which autonomously generates estimates of position, velocity and time to enable planning, prediction and execution of event-based commanding of mission operations.

Abstract: A small, multi-function device called the GPS/Telemetry Transmitter (GTT) that can recover telemetry (TM) data from missiles, spacecraft, balloons, or any moving platform or vehicle, and generate high accuracy trajectory estimates using GPS data is disclosed. Additionally, the concept underlying the GTT of transmitting high-data-rate telemetry and instrument data concurrently with transdigitized GPS data is incorporated in a GPS-Linked Transponder (GLT) resulting in a simpler and cheaper satellite positioning system.