| The Doppler difference velocity between the measured solar spectrum and the measured asteroid spectrum is the measurement of the celestial Doppler difference navigation.Theoretically,there is only a phase shift between the solar spectrum and the asteroid reflectance spectrum.However,due to the influence of the asteroid absorption effects,the asteroid reflectance spectrum has energy loss,and the spectral profile is out of shape compared with the solar spectrum.The change of the asteroid reflectance spectrum leads to the decline of the accuracy of the celestial Doppler difference velocity,which seriously affects the celestial Doppler difference navigation.To address the above issues,considering the fact that the difference between the approximation of solar spectrum and that of the asteroid spectrum can give expression to the asteroid reflectance,the paper utilize the empirical mode decomposition(EMD)to extract the approximation of celestial spectra and propose an inversion method of celestial spectrum reflectance template for celestial Doppler difference navigation.The main contents include:(1)The paper proposes an inversion method of celestial spectrum reflectance template,and applies Gaussian genetic algorithm(GGA)and EMD to this method.The spectrum is decomposed by EMD into the intrinsic mode functions(IMF)and residual,whose certain combination can build the spectrum reflectance curve and embody the spectrum reflectance.The paper utilize the spectrum reflectance curve and the measured solar spectrum to produce the virtual asteroid spectrum and adopt the Taylor method to estimate the Doppler difference velocity between the measured asteroid spectrum and the virtual one.We utilize the Gaussian function to optimize the mutation and crossover operations of genetic algorithm(GA)and propose the Gaussian genetic algorithm.Using the Doppler difference velocity errors as the object of the fitness function,the GGA optimizes the combination of IMFs.The experiment results show that the inversion method of celestial spectrum reflectance template based on GGA-EMD constructs the spectrum reflectance template effectively and improves the accuracy of the Doppler difference velocity.(2)To accelerate the convergence rate of high-dimensional optimization problems in the inversion method of celestial spectrum reflectance template,inspired by the cooperative hunting process of spider colonies named Anelosimus eximius,a new Anelosimus eximius colony algorithm(AECA)is proposed.In the AECA,a certain direction component of the problem solution is represented as a certain direction in which a spider travels,so that a high-dimensional optimization problem can be transformed into multiple low-dimensional optimization problems.To evaluate the performance of AECA,the paper studies the influence of the random walk,summoning behavior,Gaussian probability and other factors on the algorithm.The paper compares the performance of AECA with other different algorithms.The experiment results show that the AECA has excellent optimization effect and fast convergence rate. |
