Principle and performance analysis of coherent tracking sensor based on local oscillator beam nutation.

By integrating coherent tracking sensor functionality into a coherent communication receiver, a dual-function receiver with coherent boresight error sensing is developed for tracking in coherent free-space optical communication systems. The sensor principles are analyzed according to optical interference theory, and the boresight error detection algorithm and small signal linear model are derived. Analysis of local-oscillator beam nutation on system performance shows that the best nutation half-angle is 0.5-1 µrad, the noise equivalent angle is less than 0.02 µrad, and the communication sensitivity degradation is 0.2-0.6 dB. This technology opens new avenues for free-space optical communication system design.

[Development of transformation system of rice based on transformation-competent artificial chromosome (TAC) vector].

The TAC clone (NK15) containing a ca.50 kb DNA insert was introduced into Agrobacterium tumefaciens strain LBA4404 by electroporation. The NK15 was stable in Agrobacterium tumefaciens strain LBA4404 under kanamycin selection for many generations. The calli of mature embryo of Nongken58S were infected with the Agrobacterium tumefaciens strain LBA4404 carrying NK15. PCR and Southern analyses of transgenic plants indicated that the 50 kb of foreign DNA was transferred into the rice genome, and most of transgenic plants had one copy of the insertion. Genetic and PCR analyses of T1 progeny confirmed that the inserted forgein DNA was stably inherited.