Adaptive Piecewise Fitting of Shaped Rotational Paraboloid Antennas Generatrix
Abstract
Common generatrix fitting methods of the shaped rotational paraboloid antenna include polynomial overall fitting and equal-interval piecewise fitting. The order of polynomial overall fitting is high so that the calculation load is large, and the fitting result on the edge is easy to oscillate. In the second method, generatrix data is segmented into several equal intervals, but the segment method is unreasonable, which is easy to cause the result of more fitting parameters and poorer fitting smoothness. In order to solve the above problems, an adaptive piecewise fitting method based on the fitting residual distribution is proposed. The method consists of two steps: initial overall fitting and piecewise fitting. In the initial overall fitting, the fitting residual error distribution of each discrete point is calculated. In piecewise fitting, firstly, the discrete point data are segmented according to the residual error distribution. Secondly, the data of each section are fitted by low-order polynomial. The comparison of fitting example shows that the method proposed in this paper can avoid the instability of high-order fitting, reduce the number of segments, and be more suitable for the generatrix fitting of shaped rotational paraboloid antenna.
- Publication:
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Acta Astronomica Sinica
- Pub Date:
- January 2020
- Bibcode:
- 2020AcASn..61....8W
- Keywords:
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- shaped paraboloid antenna;
- paraboloid generatrix;
- polynomial overall fitting;
- equal-interval piecewise fitting;
- adaptive piecewise fitting