61 results about "Pitch angle" patented technology

In one embodiment and method of the present invention, an optical interference fly height (FH) test apparatus for measuring FH is disclosed, in accordance with an embodiment of the present invention, to include a slider, a transparent disk, means for directing a light beam directed between the slider and the disk, and means for iteratively measuring an estimated FH using at least two points of measurement on the slider when the slider is moved away from the disk at a pitch angle, wherein the estimated FH is computed as a function of the pitch angle and during each iteration, a previously-estimated FH is used to converge the estimated FH so that the estimated FH is within a predetermined range from the actual FH.

The present invention provides an attitude fusion enhanced measurement method and system based on inertial navigation technology. The method includes step 1, acquiring attitude data detected by each sensor, and performing data initialization; step 2, performing strapdown calculation on the initialized attitude data; Step 3, correct the attitude data corresponding to each sensor; Step 4, use feedback control to correct the gyro zero point according to the corrected acceleration data and magnetometer data; Step 5, output the corrected attitude data. The invention has a magnetic anomaly detection function, and the magnetic correction does not affect the pitch angle and roll angle correction; based on the nonlinear theory, better convergence speed and control precision are provided.

The invention discloses a multi-parameter alternating search-based metrewave radar low elevation height measurement method, mainly solves the problem that the error in the height measurement of up and down positions in the prior art is large. The method comprises the following implementation steps: extracting a target signal from a radar echo to obtain a covariance matrix of the target signal; calculating a synthesis steering vector by using a direct steering vector and a reflected steering vector; estimating the pitch angle of a direct wave to obtain an estimated value; estimating the pitch value of a reflected wave to obtain an estimated value; performing alternating search on a ground reflection coefficient magnitude, a ground reflection coefficient phase, the pitch angle of the direct wave and the pitch angle of the reflected wave to obtain the estimated values of each parameter; judging whether the alternating search is finished or not; searching the pitch angle of the direct wave to obtain the estimated value of the pitch angle of the direct wave, namely the precise elevation of a target; and obtaining the target height. The method does not depend on precise radar position altitude parameters; the adaptive capacity of radar to the position is enhanced; the height measurement precision is improved; and the method can be used for target positioning and tracking.