A Noise Reduction Method for Star Sensor

A star sensor, noise reduction technology, applied in the field of noise reduction, can solve problems such as discontinuity of derivatives, and achieve the effect of reducing noise

CN103376108BActive Publication Date: 2017-05-10BEIJING AUTOMATION CONTROL EQUIP INST
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-05-10

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Abstract

The invention belongs to a noise reduction method, concretely relates to a star sensor noise reduction method, and provides a star sensor noise reduction technology. The method comprises the following steps: step 1, collection of data; step 2, wavelet decomposition: a wavelet coefficient omega and a wavelet coefficient mean square error lambda are obtained through wavelet decomposition; step 3, threshold processing, the wavelet coefficients obtained from the step 2 are objected to modified threshold processing to obtain the estimated values of the wavelet coefficients, and the modified threshold method is as follows:; and step 4, wavelet inverse transformation. The beneficial effects of the method are that, the method can effectively reduce the noise of the star sensor, and because the course of the threshold processing is changed, no singular points appear during wavelet reconstruction.
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Description

technical field

[0001] The invention belongs to a noise reduction method, in particular to a star sensor noise reduction method. Background technique

[0002] There are mainly two kinds of errors in the attitude information output by the star sensor, one is fixed error, which is caused by the design and manufacture of the whole system, the inaccurate installation and correction, and the limited signal-to-noise ratio in the photoelectric conversion process of the photosensitive device. The other is random error (noise), which is composed of systematic errors caused by the star sensor zenith observation and calibration of the star distribution, brightness, and spectrum of the measured object, as well as errors caused by factors such as instruments, equipment, and working environment. The process is caused by the uneven distribution of atmospheric clouds and atmospheric temperature gradients, and the measurement data is mixed with systematic and random errors. Relatively speak...

Examples

Embodiment Construction

[0029] A star sensor noise reduction technology, comprising the steps of:

[0030] Step 1: Data Acquisition

[0031] The data to be collected is the attitude information of the star sensor, specifically: roll angle and declination angle. The accuracy of roll angle and declination angle can reflect the measurement accuracy of star sensors. When the mean square error of roll angle and declination angle is smaller, it is considered that the measurement accuracy of star sensitivity is higher.

[0032] Step 2: Wavelet Decomposition

[0033] The canonical orthogonal wavelet Daubechies wavelet is selected to process the sampled signal in four scales to obtain the corresponding wavelet coefficients. The Daubechies wavelet processing method is a commonly used wavelet processing method in the prior art, and its specific steps can be found in many documents. In this step, the wavelet coefficient ω and the mean square error λ of the wavelet coefficient are obtained. The wavelet coeff...