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For defocus generated during imaging from an oblique photographic airborne camera, a corresponding focusing mechanism was designed to compensate oblique distance defocus for high imaging quality. The principle of oblique distance defocus was analyzed, the formula of defocus compensation was obtained and a cam mechanism was proposed to compensate the defocus. A focusing mechanism based on a cylindrical cam was designed to replace the traditional focusing mechanism based on eccentric cam, in which the theoretically mode is exact instead of proximal. As the oblique distance defocus system was designed based on a typical height, the residual defocus would be emerged at other heights. The cause of residual defocus was analyzed. The process method and process flow were developed to eliminate the residual defocus. All amount of oblique distance defocus were compensated in all heights and scan angels. Camera imaging simulation with different objects in laboratory approves the validity and accuracy of the proposed focusing mechanism.

Equipped with a tilt mirror and micro-mirror replacing the moving mirror,a novel Fourier transform spectrometer is proposed based on programmable Micro-Electro-Mechanical Systems(MEMS) micro-mirror.Firstly,the working principle and the tolerance of the tilting mirror is analyzed systematically and validated experimentally.Theory results show that the limited tilt angle is 0.52° and the spectrum resolution is 8 nm in the near infrared region;while the limited tilt angle is 0.183°,the spectrum resolution is 3 nm in the visible region.Experimental measurement shows that the spectra can be reconstructed accurately in the tolerance of the tilting mirror with central wavelength 488 nm laser soure and polychromatic light soure,while distorted badly out of the tolerance range.

In consideration of the exposure precision of a curtain shutter and the dimension of a camera,a new focus-plane single curtain type shutter was designed by using a timing belt with high transmission accuracy as the curtain of shutter and a belt wheel as the roll shaft.The main reason effecting the exposure precision was analyzed,and a mathematic model was created by the system error synthesis method.Then,the series of gear-composited errors was used to evaluate the transmission errors of a driving mechanism.Furthermore,the geometric model of the polygonal effect was established by analysis of the transmission mechanism of the timing belt,and the influence of polygonal effect on the rate errors was calculated.After testing on the shutter,the speed stability of the roll shaft is obtained and the exposure precision achieves 0.067 according to the Gaussian processes.The exposure time at 5 positions on a frame was tested by the photoelectric method,and the result shows that exposure precision in the frame achieves by 0.056,which demonstrates that this shutter can exposure on the aerial photographing of large range illuminance.

As conventional transmission mechanism is difficult to realize coaxial rotation transmission in a narrow radial space,a coaxial transmission mechanism based on cylindrical cams is proposed.On the basis of the structure of a lens,the transmission mechanism is combined by two cylindrical cams,and one is initiative cam and the other is passive cam.Spiral slots are opened on the surface of both cams.When the spiral lead of the passive cam is n times that of initiative cam,the transmission mechanism can offer a transmission ratio of n.Transmission efficiency and transmission accuracy are analyzed and the relation between the angle of initiative cam's spiral slot and the transmission efficiency and transmission accuracy is discussed.An experiment is performed to test transmission accuracy,which shows the transmission ratio accuracy is less than 1.6%.Obtained mechanism has compact structure,high accuracy and can be locked automatically.

Based on the analysis of detection theory of two booms electric field instrument,the detailed design of the electric field instrument boarded on sounding rocket which is used in Meridian Project is presented.In order to reduce asymmetries and inconsistencies of the probe,aluminous spherical probe is adopted.The graphite coating is chosen to reduce the surface non-uniformity,and the particular shape design is used to eliminate the shadow effect of the boom.In order to improve the system dynamic range,four frequency ranges is selected,providing a set of analog signals subsequently directed to the data digitization and processing unit.Finally,several error considerations and the test results of system performance are presented.The bandwidth of this electric field instrument is 0～5MHz.The DC detection range is 0.1mV/m～±1V/m and the AC detection range is 10μV/m～50mV/m.The two-dimensional spatial electric field with intensity of 0～±1V/m can be measured.

A simplified physical model is built up to study the swirl flow effect induced by a rotating disk on the jet impingement behaviors, which is adopted to simulate the grinding process. To solve the definition problem of the interface between a rotating disk and a stationary plate in the computational simulation, a tiny gap is set between the rotating disk and the stationary plate. The results show that the rotating disk suspended above the surface adds more complexity to the flow field of jet impingement on a stationary plate. The swirling flow around the rotating disk obstructs the impinging jet flow to penetrate into the interfacial contact zone and forces the wall jet across the rotating disk to flow along transverse directions. For the given jet impinging velocity and nozzle orientation, as the disk rotational speed increases, the effect of the rotating disk on the impinging jet flow behaves more significantly. The impinging jet with small inject velocity is difficult to penetrate through the interfacial contact zone to follow by the disk swirl flows. For smaller jet impinging distance or larger oblique angle, the flow recirculation away from the interfacial contact zone becomes stronger.