Positioning and ground proximity warning method and system thereof for vehicle

• US 6,157,891 A
• Filed: 02/01/1999
• Issued: 12/05/2000
• Est. Priority Date: 11/16/1998
• Status: Expired due to Term

• Current Assignee: American GNC Corporation
• Original Assignee: Ching-Fang Lin
• Inventors: Lin, Ching-Fang
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Beaulieu, Yonel
• Application Number:
  US09/241,164
• Time in Patent Office: 673 Days
• Field of Search: 701/300, 701/301, 701/302, 701/200, 701/208, 701/211, 701/213, 701/220, 701/4, 701/9, 342/46, 342/118, 342/123, 342/357.11, 342/357.13, 342/357.14, 342/26, 342/63, 342/65, 342/120, 342/194, 340/963, 340/970, 73/178 T, 244/180
• US Class Current: 701/301
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial

Abstract

A positioning and ground proximity warning method for vehicle includes the steps of outputting global positioning system signals to an integrated positioning/ground proximity warning system processor; outputting an inertial navigation solution to an integrated positioning/ground proximity warning processor; measuring air pressure, and computing barometric measurements which is output to the integrated positioning/ground proximity warning processor; measuring time delay between transmission and reception a radio signal from a terrain surface, and computing radio altitude measurement which is output to the integrated positioning/ground proximity warning processor; accessing a terrain database for obtaining current vehicle position and surrounding terrain height data which is output to the integrated positioning/ground proximity warning processor; and receiving the position, velocity and time information or said pseudorange and delta range measurements of said global positioning system, the inertial navigation solution, the radio altitude measurement, the radio altitude measurement, and the current vehicle position and surrounding terrain height data, and computing optimal positioning solution data and optimal ground proximity warning solution data.

Claims

1. A positioning and ground proximity warning method for vehicle, comprising the steps of:

(a) receiving global positioning system information for deriving position, velocity and time information or pseudorange and delta range measurements of a global positioning system, and outputting said global positioning system information to an integrated positioning/ground proximity warning system processor;

(b) receiving vehicle angular rate and specific force information for computing an inertial navigation solution, including position, velocity, and attitude of said vehicle, by solving inertial navigation equations, and outputting said inertial navigation solution to said integrated positioning/ground proximity warning processor;

(c) measuring air pressure, and computing barometric measurements which is output to said integrated positioning/ground proximity warning processor;

(d) measuring time delay between transmission and reception of a radio signal from a terrain surface, and computing radio altitude measurement which is output to said integrated positioning/ground proximity warning processor;

(e) accessing a terrain database for obtaining current vehicle position and surrounding terrain height data which is output to said integrated positioning/ground proximity warning processor; and

(f) receiving said position, velocity and time information or said pseudorange and delta range measurements of said global positioning system, said inertial navigation solution, said radio altitude measurement, and said current vehicle position and surrounding terrain height data, and computing optimal positioning solution data and optimal ground proximity warning solution data.

2. A positioning and ground proximity warning method for vehicle, as recited in claim 1, wherein step (b) further comprises an additional step of receiving an optimal estimates of position errors, velocity errors and attitude errors of said inertial navigation solution and an inertial sensor measurement errors from the step (f) and performing an error feedback calibration of said inertial navigation solution to obtain improved performance.

3. A positioning and ground proximity warning method for vehicle, as recited in claim 1, wherein the step (f) comprises the steps of:

(f-1) accepting said position, velocity and time information or said pseudorange and delta range measurements of said global positioning system, said inertial navigation solution, said radio altitude measurement, and said current vehicle position and surrounding terrain height data;

(f-2) computing optimal navigation, including position, velocity, and attitude, by using said accepted position, velocity and time information of said global positioning system, said inertial navigation solution, said radio altitude measurement, and said current vehicle position and surrounding terrain height data; and

(f-3) inputting said optimal navigation solution, said surrounding terrain data from said terrain database, and a vehicle performance and configuration data from a onboard flight control and management system, and computing said ground proximity warning solution.

4. A positioning and ground proximity warning method for vehicle, as recited in claim 2, wherein the step (f) comprises the steps of:

(f-1) accepting said position, velocity and time information or said pseudorange and delta range measurements of said global positioning system, said inertial navigation solution, said radio altitude measurement, and said current vehicle position and surrounding terrain height data;

(f-2) computing optimal navigation, including position, velocity, and attitude, by using said accepted position, velocity and time information of said global positioning system, said inertial navigation solution, said radio altitude measurement, and said current vehicle position and surrounding terrain height data; and

(f-3) inputting said optimal navigation solution, said surrounding terrain data from said terrain database, and a vehicle performance and configuration data from an onboard flight control and management system, and computing said ground proximity warning solution.

5. A positioning and ground proximity warning method for vehicle, as recited in claim 3, wherein the step (f-3) comprises the steps of:

computing query parameters using said optimal navigation solution, which is sent to said terrain database to access said terrain data of said current vehicle position and surrounding terrain;

predicting a projected flight path by using said accepted optimal navigation solution and said vehicle performance and configuration data from said onboard flight control and management system;

computing and comparing, using said accepted projected flight path, said vehicle performance and configuration data from said onboard flight control and management system, and said surrounding terrain data from said terrain database, in which when said projected flight path is too close to the terrain, a warning decision message is made; and

receiving said warning decision message and said current vehicle position, velocity, and attitude information and said surrounding terrain data from said terrain database, and said vehicle performance and configuration data from said onboard flight control and management system, and computing an optimal evasion flight path.

6. A positioning and ground proximity warning method for vehicle, as recited in claim 4, wherein the step (f-3) comprises the steps of:

computing query parameters using said optimal navigation solution, which is sent to said terrain database to access said terrain data of said current vehicle position and surrounding terrain;

predicting a projected flight path by using said accepted optimal navigation solution and said vehicle performance and configuration data from said onboard flight control and management system;

computing and comparing, using said accepted projected flight path, said vehicle performance and configuration data from said onboard flight control and management system, and said surrounding terrain data from said terrain database, in which when said projected flight path is too close to the terrain, a warning decision message is made; and

receiving said warning decision message and said current vehicle position, velocity, and attitude information and said surrounding terrain data from said terrain database, and said vehicle performance and configuration data from said onboard flight control and management system, and computing an optimal evasion flight path.

7. A positioning and ground proximity warning method for vehicle, as recited in claim 6, wherein the step (f-2) comprises the steps of

individually inputting said radio altimeter measurement from a radio altimeter, said barometric altimeter measurement from a baro altimeter, and said terrain data from said terrain database to a correlation/matching;

individually collecting said radio altimeter measurement and said barometric altimeter measurement to construct a measured profile of terrain in an assigned time window, wherein said terrain data is collected to construct a set of prestored reference terrain profiles which correspond to an area over which said vehicle is flying during said assigned window time, and then comparing said measured terrain profile with said set of prestored reference terrain profiles, in which once a match is found, geographic coordinates of the best matching reference profile is passed to a filter/estimator;

forming altitude measurement residues which are passed to said filter/estimator by resulting of adding radio altimeter measurements with terrain height of the current vehicle position being differenced with the inertial altitude solution (or hybrid baro/inertial altitude measurement);

filtering said position and said velocity or said pseudorange and delta range measurements of said global positioning system, said inertial navigation solution, and said geographic coordinates of said best matching reference profile and said altitude measurement residues by said filter/estimator to obtain optimal estimates of said inertial navigation solution errors, errors of said global position system receiver, and errors of said inertial sensors in a centralized filtering fashion and feeding back said optimal estimates of said inertial navigation solution errors and said inertial sensor errors to said inertial navigation system to calibrate errors of said inertial navigation solution.

8. A positioning and ground proximity warning method for vehicle, as recited in claim 6, wherein the step (f-2) comprises the steps of:

individually inputting said radio altimeter measurement from a radio altimeter, said barometric altimeter measurement from a baro altimeter, and said terrain data from said terrain database to a correlation/matching;

individually collecting said radio altimeter measurement and said barometric altimeter measurement to construct said measured profile of terrain in said assigned time window, wherein said terrain data is collected to construct a set of prestored reference terrain profiles which correspond to said area over which said vehicle is flying during said assigned window time, and then comparing said measured terrain profile with said set of prestored reference terrain profiles in said correlation/matching, wherein when a match is found, geographic coordinates of the best matching reference profile is passed to a TAINS local filter;

forming altitude measuremnet residues to said TAINS local filter by resulting of adding said radio altimeter measurements with terrain height of said current vehicle position being differenced with said inertial altitude solution (or hybrid baro/inertial altitude measurement) in said correlation/matching;

filtering said obtained geographic coordinates of said best matching reference profile and said altitude measurement residues by said TAINS local filter to obtain a local optimal estimates of said inertial navigation solution errors and said inertial sensor errors,

accepting and filtering said position and velocity or pseudorange and delta range measurements of said global positioning system and said inertial navigation solution by a INSGPS local filter to obtain another local optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors;

accepting said local optimal estimates and covariance matrix of said inertial navigation solution errors, errors of said global position system receiver, and errors of said inertial sensor from said INSGPS local filter and said local optimal estimates and covariance matrix of said inertial navigation solution errors and errors of said inertial sensor from said TAINS local filter by a master filter, which are filtered to provide a global optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors;

feeding back said global optimal estimates of inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors and a covariance matrix obtained by said master filter to said INSGPS local filter and said TAINS local filter to reset said INSGPS local filter and said TAINS local filter, and to perform information-sharing among said master filter, said INSGPS local filter, and said TAINS local filter,

tuning communication and estimation format between said master filter, said INSGPS local filter, and said TAINS local filter;

performing a consistency test among said state estimates of said master filter, said INSGPS local filter, and said TAINS local filter by said master filter for detecting and isolating a malfunction of a satellite of said global positioning system and to reconfigure the structure and process of said navigation solution; and

feeding back said optimal estimates of said inertial navigation solution errors and inertial sensor errors to said inertial navigation system to calibrate errors of said inertial navigation solution.

9. A positioning and ground proximity warning method for vehicle, as recited in claim 6, wherein the step (f-2) comprises the steps of:

inputting said inertial navigation solution from said inertial navigation system, said baro altitude measurement from said baro altimeter, said radio altitude measurement from said radio altimeter, and said terrain data from said terrain database to an individual terrain clearance computation;

substracting said individual baro altitude (or hybrid baro/inertial altitude measurement) by a height of said terrain at a current vehicle position to form a referenced individual terrain-clearance measurement, wherein said radio altitude measurement is an individual measured terrain-clearance measurement, a deference between said measured terrain-clearance measurement, and said referenced terrain-clearance measurement is output by said individual terrain clearance computation to a filter/estimator, which is a nonlinear filter/estimator;

filtering said position and velocity or said pseudorange and delta range measurements of said global positioning system, said inertial navigation solution from said inertial navigation system, and said difference between said measured terrain-clearance measurement and said referenced terrain-clearance measurement from said individual terrain clearance computation by said filter/estimator in a centralized filtering fashion to obtain optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors; and

feeding back said optimal estimates of said inertial navigation solution errors and said inertial sensor errors to said inertial navigation system to calibrate errors of said inertial navigation solution.

10. A positioning and ground proximity warning method for vehicle, as recited in claim 6, wherein the above step (f-2) further comprises the following steps:

inputting said inertial navigation solution from said inertial navigation system, said baro altitude measurement from said baro altimeter, said radio altitude measurement from said radio altimeter, and said terrain data from said terrain database to an individual terrain clearance computation;

individually substracting said baro altitude measurement (or hybrid baro/inertail altitude measurement) by a height of said terrain at a current vehicle position to form said referenced individual terrain-clearance measurement, wherein said radio altitude measurement is said individual measured terrain-clearance measurement, and then outputting a difference between said measured terrain-clearance measurement and said referenced terrain-clearance measurement by said individual terrain clearance computation to a TAINS local filter;

modeling said inertial navigation solution errors and inertial sensor errors by said TAINS local filter, and filtering said difference between said measured terrain-clearance measurement and said referenced terrain-clearance measurement by said TAINS local filter to obtain said local optimal estimates of said inertial navigation solution errors and said inertial sensor errors, wherein said TAINS local filter is a nonlinear filter/estimator or extended Kalman filter;

accepting and processing said position and velocity or pseudorange and delta range measurements of said global positioning system and said inertial navigation solution from said inertial navigation system by an INSGPS local filter to obtain another local optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors;

filtering said local optimal estimates and covariance matrix of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors from said INSGPS local filter and said local optimal estimates and covariance matrix of said inertial navigation solution errors and said inertial sensor errors from said TAINS local filter by a master filter to provide said global optimal estimates of said inertial navigation solution errors, said errors of said global position system receiver, and errors of said inertial sensor;

feeding back said global optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors and said covariance matrix obtained by said master filter to said INSGPS local filter and said TAINS local filter to reset said INSGPS local filter and said TAINS local filter, and to perform information-sharing among said master filter, said INSGPS local filter, and said TAINS local filter;

tuning communication and estimation among said master filter, said INSGPS local filter, and said TAINS local filter to obtain different system performances, performing a consistency test among the state estimates of said master filter, said INSGPS local filter, and said TAINS local filter by said master filter to detect and isolate said malfunction of said satellite of said global positioning system and to reconfigure the structure and process of said navigation solution; and

feeding back said optimal estimates of said inertial navigation solution errors and said inertial sensor errors are fed back to said inertial navigation system to calibrate errors of said inertial navigation solution.

11. A positioning and ground proximity warning method for vehicle, as recited in claim 1, 7, 8, 9, or 10, wherein in the step (f) said optimal positioning solution data includes optimal vehicle position, velocity, acceleration, and attitude solution data, and that in the step (a) further comprises an additional step of receiving said optimal vehicle position, velocity, acceleration, and attitude solution data from the step (f) and aiding signal tracking, acquisition, and reacquisition processing of a global positioning system receiver of said global positioning system.

12. A positioning and ground proximity warning method for vehicle, as recited in claim 1, 7, 8, 9, or 10, after the step (f), further comprising an additional step of receiving said ground proximity warning solution, said optimal navigation solution, and said terrain data, and performing a synthetic vision processing to obtain an enhanced vision display for a flight crew.

13. A positioning and ground proximity warning method for vehicle, as recited in claim 11, after the step (f), further comprising an additional step of receiving said ground proximity warning solution, said optimal navigation solution, and said terrain data, and performing a synthetic vision processing to obtain an enhanced vision display for a flight crew.

14. A positioning and ground proximity warning method for vehicle, as recited in claim 1, 7, 8, 9, or 10, after the step (f), further comprising an additional step of receiving said ground proximity warning solution and performing a voice processing to obtain audible ground proximity warning messages for a flight crew.

15. A positioning and ground proximity warning method for vehicle, as recited in claim 11, after the step (f), further comprising an additional step of receiving said ground proximity warning solution and performing a voice processing to obtain audible ground proximity warning messages for a flight crew.

16. A positioning and ground proximity warning method for vehicle, as recited in claim 12, after the step (f), further comprising an additional step of receiving said ground proximity warning solution and performing a voice processing to obtain audible ground proximity warning messages for a flight crew.

17. A positioning and ground proximity warning method for vehicle, as recited in claim 13, after the step (f), further comprising an additional step of receiving said ground proximity warning solution and performing a voice processing to obtain audible ground proximity warning messages for a flight crew.

18. A positioning and ground proximity warning method for vehicle, as recited in claim 1, 7, 8, 9, or 10, wherein the step (a) comprises the steps of:

receiving a radio frequency (RF) signal of said global positioning system by said global positioning system antenna, wherein said radio frequency (RF) signal is sent to a preamplifier circuit;

amplifying said input radio frequency (RF) signal of said global positioning system by preamplifier circuit to improve its signal-noise ratio, and is output to said down converter;

converting said amplified radio frequency (RF) signal of said global positioning system by said down converter by mixing with said local referencing signal from said oscillator to said intermediate frequency (IF) signals, which is analog in-phase (I) and quadraphase (Q), wherin said IF signal is output to said band pass filter;

filtering said input IF signals by said band pass filter to filter out and filtering out said noise of said input IF signals to improve their signal-noise ratio, wherein said filtered IF signals are sent to said IF sampling and A/D converter;

sampling said input IF signals in said IF sampling and A/D converter to form said digital in-phase (I) and quadraphase (Q) signals which are output to said signal processor;

performing said signal acquisition, tracking, and reacquisition processing of said global positioning system in said signal processor by using said input digital in-phase (I) and quadraphase (Q) signals, which are aided by said optimal vehicle position, velocity, acceleration, and attitude solution data provided said integrated positioning/ground proximity warning system processor, and for computing said pseudorange, delta range, and satellite ephemeris of said global positioning system, which is output to said navigation processor; and

obtaining vehicle position, velocity, and time information by using said input pseudorange, delta range, and satellite ephemeris of said global positioning system to perform navigation computation in said navigation processor, wherein said vehicle position, velocity, and time information, or input pseudorange, delta range, and satellite ephemeris are sent to said integrated positioning/ground proximity warning system processor.

19. A positioning and ground proximity warning method for vehicle, as recited in claim 11, wherein the step (a) comprises the steps of:

receiving a radio frequency (RF) signal of said global positioning system by said global positioning system antenna, wherein said radio frequency (RF) signal is sent to a preamplifier circuit;

amplifying said input radio frequency (RF) signal of said global positioning system by preamplifier circuit to improve its signal-noise ratio, and is output to said down converter;

converting said amplified radio frequency (RF) signal of said global positioning system by said down converter by mixing with said local referencing signal from said oscillator to said intermediate frequency (IF) signals, which is analog in-phase (I) and quadraphase (Q), wherin said IF signal is output to said band pass filter;

filtering said input IF signals by said band pass filter to filter out and filtering out said noise of said input IF signals to improve their signal-noise ratio, wherein said filtered IF signals are sent to said IF sampling and A/D converter;

sampling said input IF signals in said IF sampling and A/D converter to form said digital in-phase (I) and quadraphase (Q) signals which are output to said signal processor;

performing said signal acquisition, tracking, and reacquisition processing of said global positioning system in said signal processor by using said input digital in-phase (I) and quadraphase (Q) signals, which are aided by said optimal vehicle position, velocity, acceleration, and attitude solution data provided said integrated positioning/ground proximity warning system processor, and for computing said pseudorange, delta range, and satellite ephemeris of said global positioning system, which is output to said navigation processor; and

obtaining vehicle position, velocity, and time information by using said input pseudorange, delta range, and satellite ephemeris of said global positioning system to perform navigation computation in said navigation processor, wherein said vehicle position, velocity, and time information, or input pseudorange, delta range, and satellite ephemeris are sent to said integrated positioning/ground proximity warning system processor.

20. A positioning and ground proximity warning method for vehicle, as recited in claim 12, wherein the step (a) comprises the steps of:

receiving a radio frequency (RF) signal of said global positioning system by said global positioning system antenna, wherein said radio frequency (RF) signal is sent to a preamplifier circuit;

amplifying said input radio frequency (RF) signal of said global positioning system by preamplifier circuit to improve its signal-noise ratio, and is output to said down converter;

converting said amplified radio frequency (RF) signal of said global positioning system by said down converter by mixing with said local referencing signal from said oscillator to said intermediate frequency (IF) signals, which is analog in-phase (I) and quadraphase (Q), wherin said IF signal is output to said band pass filter;

filtering said input IF signals by said band pass filter to filter out and filtering out said noise of said input IF signals to improve their signal-noise ratio, wherein said filtered IF signals are sent to said IF sampling and A/D converter;

sampling said input IF signals in said IF sampling and A/D converter to form said digital in-phase (I) and quadraphase (Q) signals which are output to said signal processor;

performing said signal acquisition, tracking, and reacquisition processing of said global positioning system in said signal processor by using said input digital in-phase (I) and quadraphase (Q) signals, which are aided by said optimal vehicle position, velocity, acceleration, and attitude solution data provided said integrated positioning/ground proximity warning system processor, and for computing said pseudorange, delta range, and satellite ephemeris of said global positioning system, which is output to said navigation processor; and

obtaining vehicle position, velocity, and time information by using said input pseudorange, delta range, and satellite ephemeris of said global positioning system to perform navigation computation in said navigation processor, wherein said vehicle position, velocity, and time information, or input pseudorange, delta range, and satellite ephemeris are sent to said integrated positioning/ground proximity warning system processor.

21. A positioning and ground proximity warning method for vehicle, as recited in claim 14, wherein the step (a) comprises the steps of:

receiving a radio frequency (RF) signal of said global positioning system by said global positioning system antenna, wherein said radio frequency (RF) signal is sent to a preamplifier circuit;

amplifying said input radio frequency (RF) signal of said global positioning system by preamplifier circuit to improve its signal-noise ratio, and is output to said down converter;

converting said amplified radio frequency (RF) signal of said global positioning system by said down converter by mixing with said local referencing signal from said oscillator to said intermediate frequency (IF) signals, which is analog in-phase (I) and quadraphase (Q), wherin said IF signal is output to said band pass filter;

filtering said input IF signals by said band pass filter to filter out and filtering out said noise of said input IF signals to improve their signal-noise ratio, wherein said filtered IF signals are sent to said IF sampling and A/D converter;

sampling said input IF signals in said IF sampling and A/D converter to form said digital in-phase (I) and quadraphase (Q) signals which are output to said signal processor;

performing said signal acquisition, tracking, and reacquisition processing of said global positioning system in said signal processor by using said input digital in-phase (I) and quadraphase (Q) signals, which are aided by said optimal vehicle position, velocity, acceleration, and attitude solution data provided said integrated positioning/ground proximity warning system processor, and for computing said pseudorange, delta range, and satellite ephemeris of said global positioning system, which is output to said navigation processor; and

obtaining vehicle position, velocity, and time information by using said input pseudorange, delta range, and satellite ephemeris of said global positioning system to perform navigation computation in said navigation processor, wherein said vehicle position, velocity, and time information, or input pseudorange, delta range, and satellite ephemeris are sent to said integrated positioning/ground proximity warning system processor.

22. A positioning and ground proximity warning method, as recited in one of claim 1, 7, 8, 9, or 10, wherein the step (b) comprises the steps of:

step b-1, measuring said vehicle angular rate and specific force information by an inertial measurement unit, and outputting said vehicle angular rate and specific force information to an error compensation;

step b-2, compensating said vehicle angular rate and specific force information in said error compensation with optimal estimates of inertial sensor errors from said integrated positioning/ground proximity warning system processor;

step b-3, updating a transformation matrix from a body frame (b frame) to a local navigation frame (n frame) by using said compensated vehicle angular rate and a rotation rate vector of said local navigation frame (n frame) with respect to an inertial frame (i frame) from an earth and vehicle rate computation, wherein said updated transformation matrix is compensated with said optimal estimates of attitude errors from said integrated positioning/ground proximity warning system processor to remove attitude errors, wherein said compensated transformation matrix is sent to a coordinate transformation computation and an attitude position velocity computation;

step b-4, transforming said compensated specific force, which is expressed in said body frame, in said coordinate transformation computation to said specific force expressed in said navigation frame, said specific force expressed in said navigation frame being output to said attitude position velocity computation;

step b-5, computing said position and velocity by using said input specific force expressed in said navigation frame, which are further compensated with said optimal estimates of position errors and velocity errors from said integrated positioning/ground proximity warning system processor, said compensated transformation matrix from the step b-3 is used to compute vehicle attitude, said compensated said position, velocity, and computed attitude being output to said earth and vehicle rate computation and said integrated positioning/ground proximity warning system processor; and

step b-6, by using said compensated said position, velocity, and computed attitude, computing a rotation rate vector of said local navigation frame (n frame) with respect to said inertial frame (i frame) in said earth and vehicle rate computation, and outputting said rotation rate vector to the step b-3.

23. A positioning and ground proximity warning met hod, as recited in claim 11, wherein the step (b) comprises the steps of:

step b-1, measuring said vehicle angular rate and specific force information by an inertial measurement unit, and outputting said vehicle angular rate and specific force information to an error compensation;

step b-2, compensating said vehicle angular rate and specific force information in said error compensation with optimal estimates of inertial sensor errors from said integrated positioning/ground proximity warning system processor;

step b-3, updating a transformation matrix from a body frame (b frame) to a local navigation frame (n frame) by using said compensated vehicle angular rate and a rotation rate vector of said local navigation frame (n frame) with respect to an inertial frame (i frame ) from an earth and vehicle rate computation, wherein said updated transformation matrix is compensated with said optimal estimates of attitude errors from said integrated positioning/ground proximity warning system processor to remove attitude errors, wherein said compensated transformation matrix is sent to a coordinate transformation computation and an attitude position velocity computation;

step b-4, transforming said compensated specific force, which is expressed in said body frame, in said coordinate transformation computation to said specific force expressed in said navigation frame, said specific force expressed in said navigation frame being output to said attitude position velocity computation;

step b-5, computing said position and velocity by using said input specific force expressed in said navigation frame, which are further compensated with said optimal estimates of position errors and velocity errors from said integrated positioning/ground proximity warning system processor, said compensated transformation matrix from the step b-3 is used to compute vehicle attitude, said compensated said position, velocity, and computed attitude being output to said earth and vehicle rate computation and said integrated positioning/ground proximity warning system processor; and

step b-6, by using said compensated said position, velocity, and computed attitude, computing a rotation rate vector of said local navigation frame (n frame) with respect to said inertial frame (i frame) in said earth and vehicle rate computation, and outputting said rotation rate vector to the step b-3.

24. A positioning and ground proximity warning method, as recited in claim 12, wherein the step (b) comprises the steps of:

step b-1, measuring said vehicle angular rate and specific force information by an inertial measurement unit, and outputting said vehicle angular rate and specific force information to an error compensation;

step b-2, compensating said vehicle angular rate and specific force information in said error compensation with optimal estimates of inertial sensor errors from said integrated positioning/ground proximity warning system processor;

step b-3, updating a transformation matrix from a body frame (b frame) to a local navigation frame (n frame) by using said compensated vehicle angular rate and a rotation rate vector of said local navigation frame (n frame) with respect to an inertial frame (i frame) from an earth and vehicle rate computation, wherein said updated transformation matrix is compensated with said optimal estimates of attitude errors from said integrated positioning/ground proximity warning system processor to remove attitude errors, wherein said compensated transformation matrix is sent to a coordinate transformation computation and an attitude position velocity computation;

step b-4, transforming said compensated specific force, which is expressed in said body frame, in said coordinate transformation computation to said specific force expressed in said navigation frame, said specific force expressed in said navigation frame being output to said attitude position velocity computation;

step b-5, computing said position and velocity by using said input specific force expressed in said navigation frame, which are further compensated with said optimal estimates of position errors and velocity errors from said integrated positioning/ground proximity warning system processor, said compensated transformation matrix from the step b-3 is used to compute vehicle attitude, said compensated said position, velocity, and computed attitude being output to said earth and vehicle rate computation and said integrated positioning/ground proximity warning system processor; and

step b-6, by using said compensated said position, velocity, and computed attitude, computing a rotation rate vector of said local navigation frame (n frame) with respect to said inertial frame (i frame) in said earth and vehicle rate computation, and outputting said rotation rate vector to the step b-3.

25. A positioning and ground proximity warning method, as recited in claim 14, wherein the step (b) comprises the steps of:

step b-1, measuring said vehicle angular rate and specific force information by an inertial measurement unit, and outputting said vehicle angular rate and specific force information to an error compensation;

step b-2, compensating said vehicle angular rate and specific force information in said error compensation with optimal estimates of inertial sensor errors from said integrated positioning/ground proximity warning system processor;

step b-3, updating a transformation matrix from a body frame (b frame) to a local navigation frame (n frame) by using said compensated vehicle angular rate and a rotation rate vector of said local navigation frame (n frame) with respect to an inertial frame (i frame) from an earth and vehicle rate computation, wherein said updated transformation matrix is compensated with said optimal estimates of attitude errors from said integrated positioning/ground proximity warning system processor to remove attitude errors, wherein said compensated transformation matrix is sent to a coordinate transformation computation and an attitude position velocity computation;

step b-4, transforming said compensated specific force, which is expressed in said body frame, in said coordinate transformation computation to said specific force expressed in said navigation frame, said specific force expressed in said navigation frame being output to said attitude position velocity computation;

step b-5, computing said position and velocity by using said input specific force expressed in said navigation frame, which are further compensated with said optimal estimates of position errors and velocity errors from said integrated positioning/ground proximity warning system processor, said compensated transformation matrix from the step b-3 is used to compute vehicle attitude, said compensated said position, velocity, and computed attitude being output to said earth and vehicle rate computation and said integrated positioning/ground proximity warning system processor; and

step b-6, by using said compensated said position, velocity, and computed attitude, computing a rotation rate vector of said local navigation frame (n frame) with respect to said inertial frame (i frame) in said earth and vehicle rate computation, and outputting said rotation rate vector to the step b-3.

26. A positioning and ground proximity warning method, as recited in claim 18, wherein the step (b) comprises the steps of:

step b-1, measuring said vehicle angular rate and specific force information by an inertial measurement unit, and outputting said vehicle angular rate and specific force information to an error compensation;

step b-2, compensating said vehicle angular rate and specific force information in said error compensation with optimal estimates of inertial sensor errors from said integrated positioning/ground proximity warning system processor;

step b-3, updating a transformation matrix from a body frame (b frame) to a local navigation frame (n frame) by using said compensated vehicle angular rate and a rotation rate vector of said local navigation frame (n frame) with respect to an inertial frame (i frame) from an earth and vehicle rate computation, wherein said updated transformation matrix is compensated with said optimal estimates of attitude errors from said integrated positioning/ground proximity warning system processor to remove attitude errors, wherein said compensated transformation matrix is sent to a coordinate transformation computation and an attitude position velocity computation;

step b-4, transforming said compensated specific force, which is expressed in said body frame, in said coordinate transformation computation to said specific force expressed in said navigation frame, said specific force expressed in said navigation frame being output to said attitude position velocity computation;

step b-5, computing said position and velocity by using said input specific force expressed in said navigation frame, which are further compensated with said optimal estimates of position errors and velocity errors from said integrated positioning/ground proximity warning system processor, said compensated transformation matrix from the step b-3 is used to compute vehicle attitude, said compensated said position, velocity, and computed attitude being output to said earth and vehicle rate computation and said integrated positioning/ground proximity warning system processor; and

step b-6, by using said compensated said position, velocity, and computed attitude, computing a rotation rate vector of said local navigation frame (n frame) with respect to said inertial frame (i frame) in said earth and vehicle rate computation, and outputting said rotation rate vector to the step b-3.

27. A positioning and ground proximity warning method for vehicle, as recited in claim 1, 7, 8, 9, or 10, wherein in the step (c), said air pressure is measured by a baro altimeter and transformed to baro altitude measurements, which are sent to said integrated positioning/ground proximity warning system processor.

28. A positioning and ground proximity warning method for vehicle, as recited in claims 26, wherein in the step (c), said air pressure is measured by a baro altimeter and transformed to baro altitude measurements, which are sent to said integrated positioning/ground proximity warning system processor.

29. A positioning and ground proximity warning method for vehicle, as recited in claim 1, 7, 8, 9, or 10, wherein in the step (d), said radio signal is sent by a radio altimeter;

echoes of said radio signal from said terrain surface is received by said radio altimeter;

said time delay between transmission and reception of said radio signal is measured and transformed to radio altitude measurement by said radio altimeter, which are output to said integrated positioning/ground proximity warning system processor.

30. A positioning and ground proximity warning method for vehicle, as recited in claim 26, wherein in the step (d), said radio signal is sent by a radio altimeter;

echoes of said radio signal from said terrain surface is received by said radio altimeter;

said time delay between transmission and reception of said radio signal is measured and transformed to radio altitude measurement by said radio altimeter, which are output to said integrated positioning/ground proximity warning system processor.

31. A positioning and ground proximity warning system for vehicle, comprising:

a global positioning system receiver for receiving global positioning system signals and deriving position, velocity and time information or pseudorange and delta range measurements of a global positioning system;

an inertial navigation system for solving navigation equations with angular rate and specific force information from an inertial measurement unit and obtaining an inertial navigation solution;

a baro altimeter for providing baro altitude measurements;

a radio altimeter for providing a radio altitude measurement from a terrain surface;

a terrain database for providing global terrain data and obtaining a terrain height of current vehicle position and surrounding terrain height data; and

a positioning/ground proximity warning system processor for receiving positioning data including said position, velocity and time information or pseudorange and delta range measurements from said global positioning system receiver, said inertial navigation solution from said inertial navigation system, said baro altitude measurements from said baro altimeter, said radio altitude measurement from said radio altimeter, said terrain height of current vehicle position and surrounding terrain height data from said terrain database, and vehicle performance and configuration data from an onboard flight control and management system, and providing optimal position, velocity, attitude navigation information and an optimal ground proximity warning information.

32. A positioning and ground proximity warning system for vehicle, as recited as claim 31, wherein said terrain database is an onboard terrain database.

33. A positioning and ground proximity warning system for vehicle, as recited in claim 31, wherein said terrain database is a ground-based terrain database by means of a data link with said vehicle.

34. A positioning and ground proximity warning system for vehicle, as recited as claim 31, wherein said positioning/ground proximity warning system processor further comprises:

an input/output module for managing input and output of said positioning data and said onboard flight control and management system;

a navigation solution module, which is connected with said input/output module and a ground proximity warning solution module, for fusing informations from all sensors to obtain an optimal navigation solution, and outputting said obtained optimal navigation solution to said onboard flight control and management system and said ground proximity warning solution module, and outputting optimal position and velocity to said global positioning system receiver, and outputting optimal estimates of inertial navigation solution error and inertial sensor errors to said inertial navigation system; and

a ground proximity warning solution module for receiving said optimal navigation solution, said terrain data, and said vehicle performance and configuration data from said onboard flight control and management system and obtain a ground proximity warning solution.

35. A positioning and ground proximity warning system for vehicle, as recited as claim 34, wherein said ground proximity warning solution module further comprise:

a query parameter computation module for receiving an optimal navigation solution from said navigation solution module, and computing query parameters, and outputting said query parameters to said terrain database to access said terrain data of said current vehicle position and surrounding terrain; and

a flight path prediction module for receiving and collecting said optimal navigation solution from said navigation solution module, and receiving said vehicle performance and configuration data from said onboard flight control and management system, and predicting a projected flight path to a warning decision module and passing said current vehicle position, velocity, and attitude to said warning decision module;

wherein said warning decision module is adapted for receiving said projected flight path from said flight path prediction, said vehicle performance and configuration data from said onboard flight control and management system, including glide slope and landing gear, and said surrounding terrain data from said terrain database and making a warning decision message, which are sent to a flight path plan aiding module; and

said flight path plan aiding module is adapted for receiving said warning decision message and said current vehicle position, velocity, and attitude information from said warning decision module, said surrounding terrain data from said terrain database, and said vehicle performance and configuration data from said onboard flight control and management system, and processing these data, and providing an optimal evasion flight path to aid a flight crew.

36. A positioning and ground proximity warning system for vehicle, as recited as claim 35, wherein a synthetic vision system is connected with said positioning/ground proximity warning system processor to provide said flight crew with an enhanced vision field display for the ground proximity warning, and a synthetic vision processing module is connected with said warning decision module, said terrain database, and said flight path plan aiding module for providing driving data for said synthetic vision system.

37. A positioning and ground proximity warning system for vehicle, as recited as claim 35, wherein a voice device is connected with said positioning/ground proximity warning system processor to provide said flight crew with audible ground proximity warning messages, and a voice processing module is connected with said warning decision module, said terrain database, and said flight path plan aiding module for providing driving data to said voice device.

38. A positioning and ground proximity warning system for vehicle, as recited as one of claims 34 to 37, wherein a bus-based structure is used for connecting said global position system, said inertial navigation system, said baro altimeter, said radio altimeter, said terrain database, said integrated positioning/ground proximity warning system processor, said synthetic vision system, said voice device and said onboard flight control and management system.

39. A positioning and ground proximity warning system for vehicle, as recited as one of claims 34 to 37, wherein said navigation solution module further comprises:

a correlation/matching, which accepts individual radio altimeter measurements from said radio altimeter, barometric altimeter measurements from said baro altimeter, and terrain data from said terrain database through said input/output module, and collects said individual radio altimeter measurements and barometric altimeter measurements to construct a measured profile of terrain in an assigned time window, and collected said terrain data to construct a set of prestored reference terrain profiles which correspond to the area over which the vehicle is flying during said assigned window time, and compared said measured terrain profile with said set of prestored reference terrain profiles, and outputs the geographic coordinates of the best matching reference profile to a filter/estimator;

wherein

said correlation/matching differencing a result of adding radio altimeter measurements with terrain height of the current vehicle position with the inertial altitude solution to form altitude measurement residuing to said filter/estimator, and said filter/estimator filtering said measurements for said global positioning system receiver, said inertial navigation solution from said inertial navigation system, and

said geographic coordinates of said best matching reference profile and altitude measurement residuing from said correlation/matching to obtain optimal estimates of said inertial navigation solution errors, errors of the global position system receiver, and errors of inertial sensors in a centralized filtering fashion, and obtaining optimal navigation solution by compensating said inertial navigation solution from said inertial navigation system with said optimal estimates of said navigation solution errors, and feeding back said optimal estimates of said inertial navigation solution errors and said inertial sensor errors to calibrate the errors.

40. A positioning and ground proximity warning system for vehicle, as recited as one of claims 34 to 37, wherein said navigation solution module further comprises:

a correlation/matching, which accepts individual radio altimeter measurements from said radio altimeter, barometric altimeter measurements from said baro altimeter, and terrain data from said terrain database through said input/output module, and collects said individual radio altimeter measurements and barometric altimeter measurements to construct a measured profile of terrain in an assigned time window, and collected said terrain data to construct a set of prestored reference terrain profiles which correspond to the area over which the vehicle is flying during said assigned window time, and compared said measured terrain profile with said set of prestored reference terrain profiles, and outputs the geographic coordinates of the best matching reference profile to a TAINS local filter, wherein

said correlation/matching differencing a result of adding radio altimeter measurements with terrain height of the current vehicle position with the inertial altitude solution to form altitude measurement residuing to said TAINS local filter;

said TAINS local filter modeling said inertial navigation solution errors and inertial sensor errors, and filtering said geographic coordinates of said best matching reference profile and altitude measurement residues to obtain a local optimal estimates of inertial navigation solution errors and inertial sensor errors,

an INSGPS local filter inputting measurements from said global positioning system receiver and said inertial navigation solution from said inertial navigation system to obtain another local optimal estimates of inertial navigation solution errors, global position system receiver errors, and inertial sensor errors,

a master filter receiving and filtering said local optimal estimates and covariance matrix of inertial navigation solution errors, errors of said global position system receiver, and errors of the inertial sensor from said INSGPS local filter and said local optimal estimates and covariance matrix of said inertial navigation solution errors and errors of said inertial sensor from said TAINS local filter, and providing global optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors,

wherein said INSGPS local filter and said TAINS local filter accepts fed back said global optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors and said covariance matrix obtained by said master filter to reset said INSGPS local filter and said TAINS local filter and performs information-sharing among said master filter, said INSGPS local filter, and said TAINS local filter,

said master filter performing a consistency test among the state estimates of said master filter, said INSGPS local filter and said TAINS local filter, to detect and isolate the malfunction of a satellite of said global positioning system and to reconfigure the structure and process of said navigation solution module,

said master filter obtaining said optimal positioning solution compensating said inertial navigation solution from said inertial navigation system with said optimal estimates of said navigation solution errors, and feeding back said optimal estimates of said inertial navigation solution errors and said inertial sensor errors to calibrate the errors.

41. A positioning and ground proximity warning system for vehicle, as recited as one of claims 34 to 37, wherein said navigation solution module further comprises:

an individual terrain clearance computation accepts said inertial navigation solution from said inertial navigation system, said baro altitude measurement from said baro altimeter, said radio altitude measurement from said radio altimeter, and said terrain data from said terrain database, wherein

said individual baro altitude measurements subtracting by a height of terrain at a current position to form a referenced individual terrain-clearance measurement, said radio altitude measurement is an individual measured terrain-clearance measurement, said individual terrain clearance computation outputting a deference between said measured terrain-clearance measurement and said referenced terrain-clearance measurement to a filter/estimator,

said filter/estimator filtering said measurements for said global positioning system receiver, said inertial navigation solution from said inertial navigation system, and said difference between said measured terrain-clearance measurement and said referenced terrain-clearance measurement from said individual terrain clearance computation in a centralized filtering fashion to obtain optimal estimates of said inertial navigation solution errors, said global position system receiver errors, and said inertial sensor errors,

wherein said filter/estimator is a nonlinear filter/estimator which obtains said optimal positioning solution by compensating said inertial navigation solution from said inertial navigation system with said optimal estimates of said navigation solution errors, and feeding back said optimal estimates of said inertial navigation solution errors and said inertial sensor errors to calibrate the errors.