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991.
Xiaodong Hu Chunguang Hu Zhi Chen Tong Guo Xiaotang Hu 《Optics & Laser Technology》2007,39(6):1176-1182
A stroboscopic Mirau microscopic interferometer system for measuring in-plane and out-of-plane periodic motions of microstructures is demonstrated. One full cycle of a periodic motion is divided into a number of motion phases. One sequence of interferograms with different phase shifting steps is collected at every motion phase by using stroboscopic imaging. A bright-field image can be extracted from one sequence of interferograms with the same motion phase. In-plane displacements are measured by applying an image matching method to all bright-field images, followed by a compensation for the relative positions of interferograms at the different motion phases, before calculating the phase distribution related to out-of-plane deformation. We demonstrate its capability for measuring a combination of out-of-plane deformation and in-plane displacement in a microresonator. 相似文献
992.
The theory of the recognized visual space of illumination (RVSI) is that the color appearance of objects in a space is determined
in relation to its recognition axis RX whose direction is determined by the brain action to adapt to the illumination in the
space. Thus the color constancy holds. RX is applicable to objects in the space but not to an object or a portion that does
not belong in the space in terms of illumination, that is to say, the luminance of which is too high based on the illumination
for that space. In that case the color appearance would be determined in relation to the fundamental axis FX and the color
constancy would not hold. In the present paper the chromaticity points were measured for a test patch that appeared achromatic
for various luminance of the patch. The points were close to the color of illumination to indicate the color constancy when
the luminance was low enough to assure its appearance as the object color, but they departed from the color of illumination
and approached the colorimetrically achromatic color. The color constancy gradually failed for the test patch with the high
luminance when the color mode became an unnatural object color and then a light color. 相似文献
993.
J. Jirmann 《International Journal of Infrared and Millimeter Waves》1984,5(5):637-642
Pyroelectric detectors are simple and rugged devices for measuring radiation from UV to Millimeter waves. In this paper a pyroelectric power meter using stock components is described. It offers some features as internal chopper background radiation compensation or calibrated detector efficiency control usually not found in commercial instruments. Calibration data at various FIR frequencies are also given. 相似文献
994.
A series of experiments were conducted to find the effects of non-uniform illumination on the surface-color mode perception. Two patterns of the illumination, one-sided illumination and a spotlight, were simulated. Observers adjusted the luminance of the test stimulus so that it just started to appear partially as an aperture-color mode. We found that the upper-limit luminance was significantly lower for all test colors when the directions of the gradient between the test stimulus and the surrounds did not match. On the other hand, in the spotlight conditions the upper-limit luminances changed only when it was contained in the spotlighted area. Our results suggest that the brightest stimulus in the scene does not work as a cue, and that the visual system takes the influence of illumination into account in order to set a criterion for the judgment for the color appearance of the mode. 相似文献
995.
机抖式激光陀螺基础振动消除研究 总被引:3,自引:7,他引:3
针对机抖式激光陀螺基础振动对测量精度影响相当严重的问题,通过理论推导和分析,并考虑实际应用中可能会带来的问题,提出了一种机抖式激光陀螺基础振动消除的原理。通过不同参数的选择,指出抖动参数的合理选择可使基础抖动力更小,重量更轻,并且易于加工,有利于系统的小型化。 相似文献
996.
提出了进行SINS姿态校正的四元补偿算法。采用闭环KF(卡尔曼滤波)技术实时校正惯性仪表误差,补偿四元数误差,修正位置,速度误差,GPS/SINS组合导航系统样机的试验结果表明:采用该提出的算法后,组合导航精度较高,在组合导航过程中若去掉GPS信息,短时间内纯SINS的导航精度很高,能够满足SAR对运动补偿精度的要求,待恢复GPS信息后,组合导航系统继续正常工作。 相似文献
997.
It is difficult but important to get clear information from the low illumination im-ages. In recent years the research of the low illumination image enhancement has become a hot topic in image processing and computer vision. The Retinex algorithm is one of the most popular methods in the field and uniform illumination is necessary to enhance low illumination image quality by using this algorithm. However, for the diff erent areas of an image with contrast brightness diff erences, the illumination image is not smooth and causes halo artifacts so that it cannot retain the detail information of the original images. To solve the problem, we gen-eralize the multi-scale Retinex algorithm and propose a new enhancement method for the low illumination images based on the microarray camera. The proposed method can well make up for the deficiency of imbalanced illumination and significantly inhibit the halo artifacts as well. Experimental results show that the proposed method can get better image enhancement eff ect compared to the multi-scale Retinex algorithm of a single image enhancement. Advantages of the method also include that it can significantly inhibit the halo artifacts and thus retain the details of the original images, it can improve the brightness and contrast of the image as well. The newly developed method in this paper has application potential to the images captured by pad and cell phone in the low illumination environment. 相似文献
998.
针对再入飞行器的惯性仪表误差模型在地面测试环境下和真实飞行环境下不一致的特点,提出了按照过载变化的大小对其误差模型进行分段辨识和分段补偿的方法,以补偿飞行器高速再入过程中的制导工具误差。最后通过计算机仿真试验验证了此方法的正确性,为实际应用提供了理论依据。 相似文献
999.
1000.
讨论了四频差动激光陀螺温变零偏的产生机理,分析了四频差动激光陀螺工作时的热源及其对陀螺在不同工作阶段的影响,实验证明了温度变化时和频和差频的强烈相关性;通过实验分析了陀螺各部分温度变化对和频和零偏的影响,研究了水晶片在温度变化时的物理性质变化,并定量计算了由其产生的广义法拉第偏频、顺逆时针偏振光差损和左右旋偏振光差损的变化对温变零偏的影响大小,结果表明:顺逆时针偏振光差损和左右旋偏振光差损对和频、差频的不同作用机理使得和频与差频的相关性变差,导致采用以和频为基准对陀螺差频进行补偿的方法具有一定的局限性,从而提出了提高以和频为基准的温补精度的措施。 相似文献