The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave...The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.展开更多
列级读出电路是目前提升平面图像传感器读出效率最为明显的方式,但是对于亿级像素超大面阵规模下的大数据大负载高速读出,列级到输出级并串转换中的列级缓冲设计面临极大的挑战.本文提出一种基于双反馈环路的列级缓冲设计方法,该方法通...列级读出电路是目前提升平面图像传感器读出效率最为明显的方式,但是对于亿级像素超大面阵规模下的大数据大负载高速读出,列级到输出级并串转换中的列级缓冲设计面临极大的挑战.本文提出一种基于双反馈环路的列级缓冲设计方法,该方法通过在列级缓冲的近端输出与远端输出间实现双反馈环路,有效抑制了列级总线的超大寄生参数对建立时间的影响,同时确保了低噪声高动态下的模拟信号精度.基于55 nm互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)工艺,在一款12288×12288像素规模的红外图像传感器中进行了成功的应用,结果表明:与传统列级缓冲相比,本文提出的双反馈环路列级缓冲设计方法可以将上升建立时间缩短23.4%,下降建立时间缩短21.9%,亿级高速图像传感器的帧率提升29.6%.展开更多
Frame processing method offers a model-based approach to Inverse Synthetic Aperture Radar(ISAR) imaging. It also provides a way to estimate the rotation rate of a non-cooperative target from radar returns via the fram...Frame processing method offers a model-based approach to Inverse Synthetic Aperture Radar(ISAR) imaging. It also provides a way to estimate the rotation rate of a non-cooperative target from radar returns via the frame operator properties. In this paper, the relationship between the best achievable ISAR image and the reconstructed image from radar returns was derived in the framework of Finite Frame Processing theory. We show that image defocusing caused by the use of an incorrect target rotation rate is interpreted under the FP method as a frame operator mismatch problem which causes energy dispersion. The unknown target rotation rate may be computed by optimizing the frame operator via a prominent point. Consequently, a prominent intensity maximization method in FP framework was proposed to estimate the underlying target rotation rate from radar returns. In addition, an image filtering technique was implemented to assist searching for a prominent point in practice. The proposed method is justified via a simulation analysis on the performance of FP imaging versus target rotation rate error.Effectiveness of the proposed method is also confirmed from real ISAR data experiments.展开更多
基金Supported by the Short-wave Infrared Camera Systems(B025F40622024)。
文摘The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.
文摘列级读出电路是目前提升平面图像传感器读出效率最为明显的方式,但是对于亿级像素超大面阵规模下的大数据大负载高速读出,列级到输出级并串转换中的列级缓冲设计面临极大的挑战.本文提出一种基于双反馈环路的列级缓冲设计方法,该方法通过在列级缓冲的近端输出与远端输出间实现双反馈环路,有效抑制了列级总线的超大寄生参数对建立时间的影响,同时确保了低噪声高动态下的模拟信号精度.基于55 nm互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)工艺,在一款12288×12288像素规模的红外图像传感器中进行了成功的应用,结果表明:与传统列级缓冲相比,本文提出的双反馈环路列级缓冲设计方法可以将上升建立时间缩短23.4%,下降建立时间缩短21.9%,亿级高速图像传感器的帧率提升29.6%.
基金Partially supported by Australian Air Force Office of Scientific Research(AFOSR)Grant(FA2386-13-1-4080)
文摘Frame processing method offers a model-based approach to Inverse Synthetic Aperture Radar(ISAR) imaging. It also provides a way to estimate the rotation rate of a non-cooperative target from radar returns via the frame operator properties. In this paper, the relationship between the best achievable ISAR image and the reconstructed image from radar returns was derived in the framework of Finite Frame Processing theory. We show that image defocusing caused by the use of an incorrect target rotation rate is interpreted under the FP method as a frame operator mismatch problem which causes energy dispersion. The unknown target rotation rate may be computed by optimizing the frame operator via a prominent point. Consequently, a prominent intensity maximization method in FP framework was proposed to estimate the underlying target rotation rate from radar returns. In addition, an image filtering technique was implemented to assist searching for a prominent point in practice. The proposed method is justified via a simulation analysis on the performance of FP imaging versus target rotation rate error.Effectiveness of the proposed method is also confirmed from real ISAR data experiments.
