| 摘要 |
PURPOSE:To achieve accurate measurement of the altitude in a low altitude flight by extropolative calculation between two beams when the amplitude difference of beams exceeds a specified max. amplitude difference. CONSTITUTION:Amplitude values[AL, AL+1]from a height measuring radar 10 are inputted into an amplitude comparator 11 to inform a data section 16 of the center beam 3 larger in the amplitude, the elevation angle of which is outputted to an elevation angle calculating section 17. The comparator 11 feeds the amplitude values AL and AL+1 of two beams to an amplitude substactor 12 to compute the difference therebetween and an absolute value¦AL-AL+1¦is taken and inputted into a comparator 13 to compare the difference in the amplitude values of the beams with AMAX value. When the comparator 13 shows AMAX<AL-AL+1, the amplitude value¦AL-AL+1¦is fed to an amplitude extrapolation section 15 to calculate an extrapolated elevation angle thereof. Elevation angles phiL and phiL+1 from the data section 16 and the extrapolated elevation angle from the amplitude extrapolation section 15 are inputted into an elevation angle calculation section 17 to determine an elevation angle which is inputted into a height measuring calculation section 18. The height measuring calculation section 18 calculates the altitude H by R sin phi with the distance R inputted from the radar 10. |
