| 摘要 |
PROBLEM TO BE SOLVED: To highly accurately measure directions while holding the size of the apparatus regardless of the content of a spreading code at the direction finding of signal radio waves by a DS-SS system. SOLUTION: Frequency conversion and A/D conversion are performed on reception signals of a plurality of antenna elements of a direction finding antenna 11 at a direction finding reception part 12. For raising the energy density of DS-SS signals having a low density of energy per unit frequency at a direction finding processing part 13, reception data of each antenna element is raised to the power of N to estimate and compute the direction of arrival of radio waves on the basis of information on the phase of the reception signals. Since it is possible to extract a carrier component of the reception signals by the addition of the raise to the power of N and thereby raise the energy density per unit frequency, such handling is enabled that sufficient reception intensity would be acquired. However, since the phase information is multiplied by N due to the raise to the power of N, an angle of elevation and an azimuth angle acquired in direction finding processing take values multiplied by N. A direction estimate value is therefore acquired by dividing them by N. COPYRIGHT: (C)2006,JPO&NCIPI
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