Discrete spectral peak estimation in incoherent backscatter heterodyne lidar. II. Correlogram accumulation

For pt.I see ibid., vol.31, no.1, p.16-27 (1993). The correlogram, an alternative to formation of the periodogram from the time series data sample. is described. The correlogram consists of a set of autocorrelation estimates for some number of lags obtained directly from the data sample. Correlogram accumulation entails adding or averaging the sets of autocorrelation estimates prior to the spectral estimation stage. The correlogram is formed in the time domain directly from the data, using a minimal number of multiplications and additions so that it may be formed and accumulated at the speed that the data are acquired