초록 ▼

A real time maximum likelihood estimator (MLE) processor employs a table look-up mechanism to eliminate the MLE computation complexity. The real time MLE processor can be implemented with digital signal processing (DSP) chips in a personal computer. Optimally accurate estimates of mean wind velocity

A real time maximum likelihood estimator (MLE) processor employs a table look-up mechanism to eliminate the MLE computation complexity. The real time MLE processor can be implemented with digital signal processing (DSP) chips in a personal computer. Optimally accurate estimates of mean wind velocity are obtained at all signals and noise ratios (SNR) using fast software algorithms.

대표청구항 ▼

[ We claim:] [1.] A method of providing a fast maximum likelihood estimation of the power, the instantaneous wind radial velocity, and the velocity spread of a small wind patch in space, said method comprising,transmitting a pulsed beam of radiation having a selected frequency to the small wind patc

[ We claim:] [1.] A method of providing a fast maximum likelihood estimation of the power, the instantaneous wind radial velocity, and the velocity spread of a small wind patch in space, said method comprising,transmitting a pulsed beam of radiation having a selected frequency to the small wind patch,capturing a returned pulsed beam of radiation which is reflected back from aerosols present in the small wind patch,said returned pulsed beam of radiation having a Gaussian power spectral density comprising,(a) an amplitude which is related to the wind path return power,(b) a frequency which is higher than the transmitted frequency by the amount of a Doppler frequency component and which Doppler frequency component can be used to estimate an average wind radial velocity over the wind patch, and(c) a width which is a function of the velocity spread wind aerosols,storing a pulsed sub-sample autocorrelation matrix in a table look-up,said table look-up comprising fixed power and velocity spread values,performing a coarse search of the received pulsed beam of radiation using the autocorrelation matrix in the table look-up to minimize a likelihood function of wind spread values and power values over the Doppler frequency component, andthen performing a fine search to find the absolute minimum of all of the power, wind radial velocity and velocity spread variables in the wind patch, and wherein the performing of the coarse search includes,performing an autocorrelation computation of the returned pulsed beam,performing a coarse search computation using the table look-up, andperforming a fast Fourier transform and select minimums computation.