초록 ▼

A system and method for improving the accuracy of altitude determinations in an inertial navigation system. Pressure measurements available to the inertial navigation system are used to initially calculate an estimated pressure altitude using the standard day model for the atmosphere. Temperature me

A system and method for improving the accuracy of altitude determinations in an inertial navigation system. Pressure measurements available to the inertial navigation system are used to initially calculate an estimated pressure altitude using the standard day model for the atmosphere. Temperature measurements are further utilized in the physical relationship between temperature, pressure, and altitude to compute a second computed altitude. A change between subsequent second computed altitudes is calculated and compared with a respective change in the computed pressure altitude in order to generate a correction value. The correction value is then used to modify the computed pressure altitude to generate a more accurate determination of the absolute altitude of the inertial navigation system. The correction value is utilized to account for changes in atmospheric conditions which may be encountered by an aircraft and to further reduce the effects of erroneous temperature and pressure measurements in subsequent altitude determinations. Thus, the system and method of the present invention provides an absolute altitude determination having improved stability and improved accuracy over prior systems.

대표청구항 ▼

[ What is claimed is:] [18.]18. A system for determining an altitude using external reference measurements, comprising:a pressure altitude conversion device for converting a received pressure measurement into a pressure altitude value;a pressure altitude differencing device which receives the pressu

[ What is claimed is:] [18.]18. A system for determining an altitude using external reference measurements, comprising:a pressure altitude conversion device for converting a received pressure measurement into a pressure altitude value;a pressure altitude differencing device which receives the pressure altitude value and computes a change between the pressure altitude value and a prior pressure altitude value;a second altitude estimation device for computed a second altitude from received pressure and temperature measurements and further calculating a change between the second computed altitude and a prior calculation of the second computed altitude;a correction value generating device for generating a correction value based upon a comparison between the change the pressure altitude and the change in the second computed altitude; andan altitude determining device for modifying the pressure altitude value using the correction value to generate an altitude determination.