Rytov variance of spherical wave and performance indicators of laser radar systems in oceanic turbulence.

Abstract The analytical expression of the spherical wave Rytov variance β 0 2 in oceanic turbulence is derived by using the Elamassie's power spectrum model (EPSM), and its correction is confirmed. The performance indicators of underwater laser radar systems, including the double-pass scintillation index σ I 2 , the aperture averaging factor A , the mean signal-to-noise ratio SNR and the mean bit-error-rate BER of monostatic system (MS) and bistatic system (BS) in oceanic turbulence are investigated. On the other hand, the difference of β 0 2 , σ I 2 and SNR between EPSM and Nikishov's power spectrum model (NPSM) is also studied. It is found that, in weak and moderate turbulence, σ I 2 is underestimated by NPSM when oceanic turbulence is dominated by the temperature fluctuations, while σ I 2 is overestimated by NPSM when oceanic turbulence is dominated by the salinity fluctuations. However, it is inverse situation in strong turbulence. Furthermore, the behavior of SNR between EPSM and NPSM is different from that of σ I 2. The relative difference of σ I 2 and SNR between EPSM and NPSM is larger for MS than that for BS. The relative difference of σ I 2 and SNR between EPSM and NPSM is larger in weak and moderate turbulence than that in strong turbulence. [ABSTRACT FROM AUTHOR]