Patent ID: 11927666
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  Y | IPC G

Claim 17:
18. A signal processing method of deriving a spectral parameter of a weak echo from
any one of (i) electric power, a spectral width, and a Doppler velocity of a topographic-echo-processed echo resulting from removal of a topographic echo in a secondary echo and (ii) electric power, a spectral width, and a Doppler velocity of an echo before topographic echo processing of the secondary echo free from the topographic echo, and
any one of (i) electric power, a spectral width, and a Doppler velocity of a topographic-echo-processed echo resulting from removal of a topographic echo in a primary echo and (ii) electric power, a spectral width, and a Doppler velocity of an echo before topographic echo processing of the primary echo free from the topographic echo,
the electric power, the spectral widths, and the Doppler velocities being found from a reception signal of a reflected wave of pulsed undulation repeatedly transmitted into a space, the signal processing method comprising:
a determination step of comparing a topographic-echo-processed secondary echo and a topographic-echo-processed primary echo with each other and making categorization into a strong echo and the weak echo;
a weak echo parameter determination step of (i) setting as weak echo parameters, a strong-topographic-echo-removed reception signal and electric power of the topographic echo in the secondary echo or the primary echo determined as the weak echo in the determination step, (ii) setting as the strong-topographic-echo-removed reception signal, a reception signal before the topographic echo processing of the secondary echo or the primary echo determined as the strong echo when the primary echo or the secondary echo determined as the strong echo in the determination step is the primary echo free from the topographic echo or the secondary echo free from the topographic echo, and (iii) setting, when the topographic echo in the primary echo or the topographic echo in the secondary echo determined as the strong echo is present, an echo resulting from removal of the topographic echo as the strong-topographic-echo-removed reception signal; and
a spectral parameter output step of providing as spectral parameters of the weak echo, (i) electric power of the weak echo estimated from a reception signal in a weak echo region obtained by phase correction of a reception signal resulting from removal of a frequency component of the strong echo from the strong-topographic-echo-removed reception signal representing the weak echo parameter, (ii) the spectral width of the weak echo representing a weak echo parameter, and (iii) the Doppler velocity of the weak echo, wherein
the spectral parameter output step includes providing as the spectral parameter of the weak echo, when the topographic echo in the secondary echo or the topographic echo in the primary echo determined as the weak echo is present, electric power of the weak echo obtained by correcting electric power of the weak echo estimated from the reception signal in the weak echo region with electric power of the topographic echo representing the weak echo parameter in a weak echo strength correction step.