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Abstract: On the basis of the phase-differential locating equation obtained by the correspondence relationship between radial distance and phase, applying the trigonometric equation obtained by cosine law, the set of linear equation solving the target position can be obtained only by simple mathematical manipulation. Now, the location parameter of target can be solved and the accurate DF formula can be derived for the phase interference array with double baseline in one-di- mensional space. The verification for accurate solution and analysis for measuring error can be worked out by using the equivalence between path length difference and phase difference. But also, the analysis process is not related to the integer of wavelength and phase-differential measurement of discriminator. The study in this paper provides a theoretical basis for the correction of the measurement accuracy to the existing approximate solution obtained by the assumption of parallel incident wave.
After making the differential transformation for direction finding based on phase interferometry, the formula of angular velocity can be obtained by measuring frequency difference. Further, the measurement for frequency differ- ence can be transformed into phase difference measurement as soon as the function relationship between frequency shift and phase shift is introduced. The analog calculation validates that derived formula only based on phase difference measurement is correctness. The error analysis shows that the new method which has the performance of real-time measurement can achieve the measurement accuracy less than 1 mrad/s after synchronously calculating the measurement error of phase difference and airborne platform flight speed.
At present, in the process of urban and rural integration, a wide gap of professional skilled per- sonnel, restricting the carrying out of the urban-rural integration, and vocational education is an important way to cultivate skilled personnel, the correct guide on the development of vocational education in promoting the integration of urban and rural areas have very great significance. In this regard, this paper explores the requirements for the development of vocational education and vocational education in urban and rural inte- gration problems, based on the development of integrated urban and rural construction requirements of the proposed countermeasures of the development of vocational education, vocational education in order to promote the integration of urban and rural play a greater role.
While the virtual short baseline is constructed by using the ratio subtraction in contrary terminal for adjacent two baselines, the differential of wavelength integer is not to zero in some arrival angle direction and but there is a jump. At the same time, there is also jump problem while using the DF result of virtual short baseline without phase ambiguity solves the phase ambiguity valuation of long baseline. The analysis in this paper shows that the emendation can be realized by distinguishing for the sinusoidal valuation of arrival angle. Also, the modifying factor is namely the proportional factor of differential between two baselines. Finally, applying the accurate DF formula explains in theory that higher accuracy of DF can be obtained by using two baselines arrays after revising without considering the phase error.
Firstly, the derivation process of an accurate DF formula based on one-dimensional linear array with two baselines is described. Then, the Doppler shift formula based on phase difference measuring is obtained by simple substitution for angle according to Doppler shift equation. As compared with the Doppler shift formula derived from approximative DF formula based on phase difference measuring, the one derived from accurate DF formula is more veracious. Error analysis shows that the measurement error of Doppler shift is less than 5 Hz within arrival angle range when baseline is about dozens of wavelengths.
A new method for detection of time difference rate using short baseline array on airborne platform is presented by measuring the phase shift in multichannel way. The time difference expression based on phase difference measurement can be solved according to phase difference and time difference location equation. Further, the time difference rate based on phase difference measurement can be derived by differential and making use of the functional relationship between phase shift and Doppler shift. On the other hand, the time difference rate based on frequency difference measurement can be obtained if we do the differential analyzer for direction finding formula. The analog calculation validates that derived formula of time difference rate are all correct. The elementary error analysis shows that the measurement accuracy of time difference rate based on phase difference or frequency difference is higher for having the light velocity whose order of magnitude is enormous in denominator of formula. The major contribution in this paper is that the time difference rate on airborne platform can be in real time detected by phase interferometry with short-baseline array.