RESUMO
In Fizeau interferometry for high-numerical-aperture spherical surface tests, the mechanical phase shift becomes spatially nonuniform within the observation aperture. We divided the aperture into annular regions and calculated the object phase using several algorithms designed for different phase shifts. The division substantially decreased the nonuniformity; however, it caused bias errors at the regional boundaries in the measured phase. The error is due to the different error coefficients of the algorithms for the phase-shift nonlinearity. A convolution technique that modifies a sampling window to align the error coefficients of a set of algorithms is proposed. The technique is experimentally shown to minimize phase measurement errors.
RESUMO
A network of the emergency telemedicine for mountain climbers in Japan Alps area has been developed. The network consists of 2.4GHz wireless LAN with over 30 km distance to be connected the Cable TV LAN. We confirmed that this network is able to transfer the high quality video and audio signal suitable for the telemedicine between the mountain huts and hospitals. In this paper, we pointed out the shortcomings of wireless LAN system and cable TV network system in use for the telemedicine, and wireless LAN module covered more than 30km and an extension system of upstream frequency bandwidth for Cable TV network. Experiments suggested that a low cost and long distance wireless LAN is useful for mountain climber's emergency telemedicine.
