Navigation receiver with coupled signal-tracking channels

A tracking receiver for use on fixed or mobile platforms in the cooperative tracking of other platforms, said other platforms being known as tracked platforms, said mobile tracking platforms being equipped with independent navigation means, said tracked platforms being of a variety of types, some types of said tracked platforms being equipped with platform velocity sensors that provide velocity inputs to said tracking receiver by means of a communication link, said velocity sensors being characterized by a velocity bias parameter, some types of said tracked platforms being equipped with attitude reference systems that provide inputs to said tracking receiver by means of said communication link of heading in some cases, heading and elevation in other cases, and heading, elevation, and yaw in still other cases, all of said attitude data being referenced to an earth-fixed coordinate system, said tracked platforms being characterized by platform dynamics characterization data comprising platform velocity random process correlation time, platform rotation rate random process correlation time, platform velocity random process state noise disturbance power, and platform rotation rate random process state noise disturbance power, said tracking receiver being capable of receiving signals through a plurality of spatially-distributed receiver ports, said signals being transmitted from said tracked platform to said tracking platform over a plurality of line-of-sight paths, said transmitted signals being modulated sinusoidal carriers transmitted through at least one transmit port, said received signals being characterized by signal parameters comprising carrier phase, carrier frequency, modulation phase, modulation phase rate-of-change, and carrier amplitude, said navigation receiver comprising:

• a means for periodically measuring the correlations of each of said plurality of received signals with a plurality of reference signals, said measured correlations having noise components characterized by a correlation measurement noise covariance matrix;
• and
• a means for periodically estimating the values of a plurality of said signal parameters for each of said plurality of received signals, said estimating means utilizing said correlation measurements for a plurality of said received signals in obtaining said estimated signal parameter values for each of said received signals thereby obtaining more reliable estimates of said signal parameter values for each of said received signals than could be obtained by direct measurements of said signal parameters for each of said received signals or by estimates of said signal parameters based only on information derived from the received signal to which each pertains.

A method of using a navigation receiver on platforms or vehicles of a variety of types, some types of said platforms being equipped with platform velocity sensors that provide velocity inputs to said receiver, said velocity sensors being characterized by a velocity bias parameter, some types of said platforms being equipped with attitude reference systems that provide inputs to said receiver of heading in some cases, heading and elevation in other cases, and heading, elevation, and yaw in still other cases, all of said attitude data being referenced to an earth-fixed coordinate system, said platforms being characterized by platform dynamics characterization data comprising platform velocity random process correlation time, platform rotation rate random process correlation time, platform velocity random process state noise disturbance power, and platform rotation rate random process state noise disturbance power, said receiver being capable of receiving a plurality of signals, said signals being transmitted by a plurality of spatially-distributed transmitters with known positions and velocities and being propagated to said receiver over a plurality of line-of-sight paths, said transmitted signals being modulated sinusoidal carriers, said transmitted signals being particular functions of time, said time being maintained in synchronized transmitter clocks, said transmitted signals being received through at least one of a plurality of spatially-distributed receiver ports, said received signals being characterized by signal parameters comprising carrier phase, carrier frequency, modulation phase, modulation phase rate-of-change, and carrier amplitude, said receiver having a clock, said receiver clock being maintained in synchronism with said transmitter clocks, said navigation receiver comprising:

• a means for periodically measuring the correlations of each of said plurality of received signals with a plurality of reference signals, said measured correlations having noise components characterized by the correlation measurement noise covariance matrix;
• and
• a means for periodically estimating the values of a plurality of said signal parameters for each of said plurality of received signals, said estimating means utilizing said correlation measurements for a plurality of said received signals in obtaining said estimated signal parameter values for each of said received signals thereby obtaining more reliable estimates of said signal parameter values for each of said received signals than could be obtained by direct measurements of said signal parameters for each of said received signals or by estimates of said signal parameters based only on information derived from the received signal to which each pertains;
• said method of using comprising the steps;
• recording said received signals prior to measuring said correlations;
• playing back said recorded signals into said correlation measuring means in place of said real-time received signals, said correlation measuring means thereby periodically measuring the correlations of each of said plurality of recorded received signals with a plurality of reference signals.

A method of using a tracking receiver on fixed or mobile platforms in the cooperative tracking of other platforms, said other platforms being known as tracked platforms, said mobile tracking platforms being equipped with independent navigation means, said tracked platforms being of a variety of types, some types of said tracked platforms being equipped with platform velocity sensors that provide velocity inputs to said tracking receiver by means of a communication link, said velocity sensors being characterized by a velocity bias parameter, some types of said tracked platforms being equipped with attitude reference systems that provide inputs to said receiver by means of said communication link of heading in some cases, heading and elevation in other cases, and heading, elevation, and yaw in still other cases, all of said attitude data being referenced to an earth-fixed coordinate system, said tracked platforms being characterized by platform dynamics characterization data comprising platform velocity random process correlation time, platform rotation rate random process correlation time, platform velocity random process state noise disturbance power, and platform rotation rate random process state noise disturbance power, said receiver being capable of receiving signals through a plurality of spatially-distributed receiver ports, said signals being transmitted from said tracked platform to said tracking platform over a plurality of line-of-sight paths, said transmitted signals being modulated sinusoidal carriers transmitted through at least one transmit port, said received signals being characterized by signal parameters comprising carrier phase, carrier frequency, modulation phase, modulation phase rate-of-change, and carrier amplitude, said tracking receiver comprising:

• a means for periodically measuring the correlations of each of said plurality of received signals with a plurality of reference signals, said measured correlations having noise components characterized by the correlation measurement noise covariance matrix;
• and
• a means for periodically estimating the values of a plurality of said signal parameters for each of said plurality of received signals, said estimating means utilizing said correlation measurements for a plurality of said received signals in obtaining said estimated signal parameter values for each of said received signals thereby obtaining more reliable estimates of said signal parameter values for each of said received signals than could be obtained by direct measurements of said signal parameters for each of said received signals or by estimates of said signal parameters based only on information derived from the received signal to which each pertains;
• said method of using comprising the steps:
• recording said received signals prior to measuring said correlations;
• playing back said recorded signals into said correlation measuring means in place of said real-time received signals, said correlation measuring means thereby periodically measuring the correlations of each of said plurality of recorded received signals with a plurality of reference signals.

A method for obtaining navigation data from signals received from a plurality of spatially-distributed reference transmitters with known positions and velocities, said method being used on platforms or vehicles of a variety of types, some types of said platforms being equipped with platform velocity sensors, said velocity sensors being characterized by a velocity bias parameter, said velocity and velocity bias parameter being used in practicing said method, some types of said platforms being equipped with attitude reference systems that provide heading in some cases, heading and elevation in other cases, and heading, elevation, and yaw in still other cases, said attitude data being used in practicing said method, all of said attitude data being referenced to an earth-fixed coordinate system, said platforms being characterized by platform dynamics characterization data comprising platform velocity random process correlation time, platform rotation rate random process correlation time, platform velocity random process state noise disturbance power, and platform rotation rate random process state noise disturbance power, said platform dynamics data being used in practicing said method, said transmitted signals being modulated sinusoidal carriers, said transmitted signals being particular functions of time, said time being maintained in synchronized transmitter clocks, said transmitted signals being propagated to said platforms over a plurality of line-of-sight paths and being received through at least one of a plurality of spatially-distributed receiving ports, said received signals being characterized by signal parameters comprising carrier phase, carrier frequency, modulation phase, modulation phase rate-of-change, and carrier amplitude, said method comprising the steps:

• measuring periodically the correlations of each of said plurality of received signals with a plurality of reference signals, said measured correlations having noise components characterized by the correlation measurement noise covariance matrix;
• and
• estimating periodically the values of a plurality of said signal parameters and the projection of said velocity sensor bias on the line-of-sight path for each of said plurality of received signals, said estimating means utilizing said correlation measurements for a plurality of said received signals, the projections of said platform velocity on said line-of-sight paths, said correlation measurement noise covariance matrix, and said platform dynamics data in obtaining said estimated signal parameter values for each of said received signals thereby obtaining more reliable estimates of said signal parameter values and velocity bias projection for each of said received signals than could be obtained by direct measurements of said signal parameters and velocity bias projection for each of said received signals or by estimates of said signal parameters and velocity bias projection based only on information derived from the received signal to which each pertains.

A method of cooperatively tracking mobile platforms known as tracked platforms, said tracked platforms transmitting at least one signal, said method being practiced on fixed or mobile platforms known as tracking platforms, said mobile tracking platforms being equipped with independent navigation means, said tracked platforms being of a variety of types, some types of said tracked platforms being equipped with platform velocity sensors that provide velocity inputs to said tracking receiver by means of a communication link, said velocity sensors being characterized by a velocity bias parameter, said velocity and velocity bias parameter being used in practicing said method, some types of said platforms being equipped with attitude reference systems that provide inputs by means of said communication link of heading in some cases, heading and elevation in other cases, and heading, elevation, and yaw in still other cases, said attitude data being used in practicing said method, all of said attitude data being referenced to an earth-fixed coordinate system, said tracked platforms being characterized by platform dynamics characterization data comprising platform velocity random process correlation time, platform rotation rate random process correlation time, platform velocity random process state noise disturbance power, and platform rotation rate random process state noise disturbance power, said platform dynamics data being used in practicing said method, said signals being transmitted from said tracked platform to said tracking platform over a plurality of line-of-sight paths, said signals being received through a plurality of spatially-distributed receiving ports, said transmitted signals being modulated sinusoidal carriers transmitted through at least one transmit port, said received signals being characterized by signal parameters comprising carrier phase, carrier frequency, modulation phase, modulation phase rate-of-change, and carrier amplitude, said method comprising the steps:

• measuring periodically the correlations of each of said plurality of received signals with a plurality of reference signals, said measured correlations having noise components characterized by the correlation measurement noise covariance matrix;
• and
• estimating periodically the values of a plurality of said signal parameters and the projection of said velocity sensor bias on the line-of-sight path for each of said plurality of received signals, said estimating means utilizing said correlation measurements for a plurality of said received signals, the projections of said platform velocity on said line-of-sight paths, said correlation measurement noise covariance matrix, and said platform dynamics data in obtaining said estimated signal parameter values for each of said received signals thereby obtaining more reliable estimates of said signal parameter values and velocity bias projection for each of said received signals than could be obtained by direct measurements of said signal parameters and velocity bias projection for each of said received signals or by estimates of said signal parameters and velocity bias projection based only on information derived from the received signal to which each pertains.