複合波変調方式FM-CW電波高度計の研究
1976 年 1976 巻 14 号 p. 1-30
詳細
1976 年 1976 巻 14 号 p. 1-30
A composite-wave FM-CW radar altimeter is investigated from the view point of aircraft landing sensor.
The new altimeter has two distinctive features. One is the reduction of step error by frequency-modulating transmitted wave with a composite wave. The other is the suppression of spurious signals with narrow-band process of constant beat frequency receiving.
The system design of the altimeter is discussed here on the basis of experimental results and theoretical analysis. Considerations are made on the various factors which give influence on the height measurement errors, such as the band width of the receiver, the cross coupling between the receiving and transmitting antennas, the beam width of the antenna, the condition of reflection surface and the attitude of aircraft. As transmitting power budget, the external loop loss is introduced and the influence of beam patterns of antennas, and characteristics of the ground are analized.
Flight test has been made to examine the error of height measurement and the external loop loss.
