中国科学院遥感与数字地球研究所-高光谱遥感应用技术研究室

【作者】             刘团结                                                                                                                                             

【导师】             童庆禧；徐根兴

【 学位年度 】    2002

【论文级别】      博士    

【关键词】          航空遥感，多光谱，数字相机，图像采集，辐射纠正，波段配准  

【Key words】   Airborne remote sensing; Multispectral; Digital camera; Imageacquire; radiometric correct; band register 

【中文摘要】 

本文以航空多光谱数字相机系统的关键技术及其在蝗灾监测方面的应用为主要研究内容。完成了一些具有创新意义的研究工作，主要包括：

1. 采用了不同结构数字相机组合的系统总体设计方案，成功地研制了以面阵CCD 为基础的综合性航空多光谱数字相机系统。系统包括三种结构的多光谱数字相机，Basler 多相机加滤光片系统、MS4100 单镜头分光式相机系统和柯达专业单反型数字相机系统，它们有独立的硬件和控制软件，既可以分开独立工作，也可以组合在一起同时使用；解决了高速大容量图像数据采集问题，系统采用的IEEE-1394 总线接口和Camera Link 接口技术是最新发展起来的图像采集技术，代表了当今图像采集系统的发展潮流；设计并实现了由三片8253CTC 芯片构成的可编程同步触发控制电路，触发间隔时间可以编程控制。触发电路的输入采用GPS 时标输出，这样做有两个好处，一是保证了定时脉冲的时间精度，二是可以获得曝光时刻相机的最高定位精度；开发了完善的系统控制软件，包括图像采集控制软件、GPS 数据采集和触发电路控制程序，提供手动、自动和外触发三种拍摄方式，实现了系统监视、图像快视、图像及辅助信息自动记录等多种功能，软件采用VC++6.0 开发，支持WINDOWS NT/2000等操作系统，功能完善，界面友好，运行可靠。

2. 在国内首次采用航空多光谱数字相机系统来进行蝗虫探测的应用研究。通过分析东亚飞蝗的生理生境特性，指出了航空遥感监测的技术途径，即通过监测蝗虫群体对植被光谱特性的影响和监测受蝗虫危害植被的光谱变化，来达到发现蝗虫的目的。并于2002 年8 月在河北南大港农场蝗区完成了蝗虫灾害监测飞行实验，获取了大量高质量的航空多光谱遥感图像，实验结果表明遥感监测蝗虫是可行的，同时也验证了新研制的航空多光谱相机是一套成功的实用化系统。

3. 对于使用电子快门的帧转移型面阵相机而言，在帧转移的过程中，一部分还没移入光遮蔽区的象元电荷会继续受到相应位置处入射光的照射，因而像元电荷在帧转移过程中受到污染，形成帧转移模糊。本文首次提出了针对帧转移型面阵CCD 器件的辐射纠正算法，即帧转移模糊的复原算法，并在地面和航空实验中得到了验证。

4. 在多光谱图像辐射纠正方面，提出了基于统计方法的模板综合校正方法，来进行多波段图像的辐射纠正，从对1431 景5 波段图像纠正的结果分析，处理效果令人满意。

5. 在系统波段配准方面，分析了光学配准的技术和难度之后，提出了采用图像配准的软件处理方法，编制了一套多波段图象自动配准程序，很好地解决了波段配准的问题，降低了系统安装和使用的要求，五个相机在安装时，并不需要调整相机视场到象元级精度，只要求五个相机的视场大致相同并保证同步曝光即可。而且更换不同焦距的镜头和不同的滤光片也不会受到配准的限制。增加了多光谱相机系统的灵活性和实用性。 

【Abstract】

The major objective this thesis is the key technique research of the airborne multispectral digital camera system and its application on the remote sensing of oriental migratory locust. The main research works are list bellow：

1. An airborne multispectral digital camera system has been successfully developed based on area CCD sensors and other peripheral facilities. In fact, the whole system includes three different multispectral camera systems, Basler cameras with optical filter system, MS4100 high-resolution 3-CCD digital multispectral cameral and Kodak professional DCS760 camera. Those systems have their independent hardware and control software, and they can be used either in combine mode or separate mode. IEEE-1394 Bus and Camera Link technique are used to capture the image data. IEEE-1394 Bus and Camera Link are the latest advance in communications interface technology for transmitting digital data. The computer, controlled by a executable program under windows operating system, provides all control functions including exposure time control, exposure interval control, retrieving images from grabber, saving images to disk array, displaying captured images for real time monitor and recording GPS information. The GPS receiver provide 1PPS pulse signal to trigger circuit, and provide the GPS locations to the control computer as well. The control programs are developed using VC++6.0, and compatible with WINDOWS NT/2000 operating system.

 2. For the first time in China, the airborne multispectral digital camera system was used to research the remote sensing of the oriental migratory locust. After analyzing the biological and environmental characteristics of the locust, the detect method was proposed that we can monitor the spectral changes of the vegetable caused by the locusts. In august 2002, a flight experiment had been done to monitor the locust area in Nandagang farmland in Hebei province. A large amount of excellent image were acquired in this experiment. And the result denoted that the airborne remote sensing method was feasible. On the other hand, the result indicated that the newly designed digital camera systems were successful.

3. For frame transfer CCD sensor, in the phase of the frame data transferring, the light source still hit the sensors surface while part of the image was moving toward the light shielded region. So the image was polluted, and we call this frame transfer smear. In this thesis, a restoration algorithm has been proposed to recover the frame transfer smear. And effect of this algorithm had been testify by many ground and flight images.

4. On the radiometric correct process of multispectral image, an in-flight statistic template correcting method was introduced. And this method was testified using 1431 multispectral images acquired in the test flight.

5. After analyzing the difficulties and disadvantages of the optical band register, image register method was adopted instead of the optical register. This is implemented by using the precise hardware synchronic trigger control circuit and the after flight image process. As a result, the camera heads do not need to be aligned at the precision of pixel level. The only requirement is that the field of view of all cameras is roughly the same. One more advantage of image register is that the replacement of different lens and optical filters would not be limited in this system. This will greatly enhance the system performance and adjustability.