中国海洋水色遥感器瑞利散射定标研究

水色遥感是海洋环境监测的主要技术手段之一.对于任何海洋水色遥感器来说,监测其在轨期间的定标系数变化是非常重要的,否则无法得到精确的定量产品.以我国“HY-1B”卫星水色遥感器为研究对象,开展了基于大洋水体上空的瑞利散射定标方法研究,利用通过对SeaWiFS数据叶绿素、离水辐亮度和气溶胶产品进行分析,选择了符合条件的7个海区实施大气瑞利散射定标,根据2010年12月份选定的4个区域定标结果得到不同海区/不同时间获得的定标系数一致性较好,CH1至CH6的定标系数标准差分布在0.9％～2.1％的范围内,因此瑞利散射定标是有效的非现场定标方法,具有较高的定标精度,其总误差在4.09％.     

剖面仪/表面仪绝对辐射定标

保证现场测量离水辐射率精度的关键工作之一是现场测量设备进行严格的实验室定标,本文就１９９９年９月进行的一次实验室绝对辐射定标试验,简述辐照度,辐亮度定标的主要方法及数据处理方法。     

东海试验区水体光谱特性现场测量与数据分析

星载水色遥感器 Ｓｅａ Ｗｉ Ｆ Ｓ 已业务化地为海洋学家提供高质量的海洋水色遥感数据。要有效地利用水色遥感数据,需要经常地对遥感器进行定标,并对测得的离水辐射率以及导出的生物—光学特性进行真实性检验。１９９８ 年５ 月, 我们在东海试验区,应用多光谱剖面／ 表面辐射仪（ Ｓ Ｐ Ｍ Ｒ／ Ｓ Ｍ Ｓ Ｒ） ,进行了光谱测量。本文介绍了现场测量的方法,以及根据我国海区的特点对实测数据的处理结果     

SAS测量水体表观光学参数的方法

SeaWiFS航空模拟器（SAS）是专门为在水面之上测量水体表观光学参数的现场设备。文章在介绍SAS现场测量以及数据处理基本方法的基础上，分析了2002年黄海试验SAS的应用效果，并与剖面法测量数据进行了比对。     

海水营养盐现场自动测量定标方法研究

对海水营养盐现场自动测量定标方法进行了优化研究.实验研究了五种营养盐混合定标和三点定标方法.对优化后的方法进行了准确度的检验,同时用实际海水与国标法进行了比对实验.     

用于水色卫星性能跟踪的西北太平洋自然目标优选研究

利用空间分布均匀、海洋与大气光学特性年际稳定性高的海洋区域作为自然基准场,是开展水色卫星遥感器定标检验和长期辐射性能跟踪最为经济便捷的方式。本文以西北太平洋海域为例,利用2008—2018年共计11年的MODIS L3级月平均数据,从空间均匀度、季节变化性、年际稳定性上进行了场区更优化筛选,优选区域更加均匀,呈微弱的季节性变化和非常一致的年际变化,适合全年开展定标检验和遥感器辐射性能跟踪工作。     

光学仪器实验室绝对辐射定标及现场质量跟踪

为保证现场测量离水辐射率的精度，对现场测量光谱仪进行严格的实验室绝对辐射定标是必不可少的。另外，由于现场试验环境复杂，要在野外长期试验，需要随时监测仪器的工作状态是否稳定。文章以加拿大Satlantic公司的光学仪器航空模拟器（SAS－Ⅱ）为例业阐述实验室绝对辐射定标的方法，类似可推广至同类光学传感器的实验室绝对辐射定标；根据SeaWiFS质量监控器（SQM－Ⅱ）监测剖面仪／表面仪的变化来阐述现场质量跟踪的方法。     

HY-1卫星水色扫描仪的辐射定标与真实性检验

主要阐述HY－1卫星10波段水色扫描仪辐射定标与真实性检验的基本原理和关键参数的测量方法，简要介绍已开展的工作，并对2类水体测量方法提出几点建议。     

双星串飞编队测高模式下高度计定标方案构想

针对新型双星串飞编队测高模式下高度计定标需求,提出了融合绝对定标与相对定标的综合定标方案构想。梳理了当前国际上主流的绝对定标方法,根据编队模式常规任务阶段的卫星轨道特点,提出了在常规长回归周期轨道之外增加天回归定标轨道的建议,在此前提下,给出了两种轨道阶段的定标方案建议,即:在定标任务阶段,绝对定标以验潮站法为主、GNSS浮标法和锚泊阵列法为辅;在常规任务轨道阶段,使用全球海域测量数据进行相对定标,绝对定标可选择适当海域结合GNSS浮标法和验潮站法实施。     

海水现场水色色度及渤海水域水色色度分析

叙述了目前海水现场水色测量的弊端 ,指出数字化海洋水色的潜在应用价值 ;根据色度学及色度学的三原色基本理论 ,确定海洋现场水色的色度要素 ,使海洋现场水色标号统一为物理学中严格的颜色物理量。结合 1 996年渤海水域光谱反射测量 ,对渤海水域 4个典型站位的反射光谱做了水色色度分析 ,并进行了 2种测量方法的比较     

自研高精度pH传感器的标定、校正方法及其在海水原位观测中的应用

电化学方法是测量海水pH值的主要方法之一。针对自主研发的基于铱金属及其氧化物电极的pH传感器,建立了海水环境下仪器标定和数据校正的方法,并在近岸和大洋环境中进行了原位测试的应用。仪器标定包括：(1)依照海水pH分析的标度要求选取适当的标定缓冲试剂;(2)以标准海水替代常用的2-氨基吡啶(AMP)溶液制备标定缓冲体系。数据校正主要包括温度背景校正及误差校正。海区原位测试应用以及与其他同类仪器对比表明,标定体系差异带来的误差可达1.00 pH单位,数据校正可提升测试精度0.10～3.00 pH单位不等。仪器的标定与数据校正方法能有效提高该自研pH传感器的测量精度。     

Preliminary calibration results of the HY-2B altimeter’s SSH at China’s Wanshan calibration site

Satellite altimeter needs to be calibrated to evaluate the accuracy of sea surface height data. The dedicated altimeter calibration field needs to establish a special calibration strategy and needs to evaluate its calibration ability. This paper describes absolute calibration of HY-2B altimeter SSH using the GPS calibration method at the newly Wanshan calibration site, located in the Wanshan Islands, China. There are two HY-2B altimeter passes across the Wanshan calibration site. Pass No. 362 is descending and the ground track passes the east of Dan’gan Island. Pass No. 375 is ascending and crosses the Zhiwan Island. The GPS data processing strategy of Wanshan calibration site was established and the accuracy of GPS calibration method of Wanshan calibration site was evaluated. Meanwhile, the processing strategies of the HY-2B altimeter for the Wanshan calibration site were established, and a dedicated geoid model data were used to benefit the calibration accuracy. The time-averaged HY-2B altimeter bias was approximately 2.12 cm with a standard deviation of 2.08 cm. The performance of the HY-2B correction microwave radiometer was also evaluated in terms of the wet troposphere path delay and showed a mean difference ?0.2 cm with a 1.4 cm standard deviation with respect to the in situ GPS radiosonde.     

基于荧光猝灭溶解氧传感器的校准方法研究

溶解氧是海洋水质监测的常规关键参数,基于荧光猝灭原理研制的溶解氧传感器具有准确度高、稳定性好和可长期在线测量等优点,已经被广泛用于海水溶解氧浓度监测.针对传感器可能发生的数据漂移和显著偏差可能造成的准确度问题,本文设计了一套专门的校准装置和校准方法.通过严格控制校准水体的温度和溶解氧浓度,测量待校准传感器和参比传感器的...     

Alkalinity determination in hypersaline solutions: a method for overcoming glass electrode errors

The non-ideality of commercially available glass pH electrode normally used for alkalinity determination by the Gran-type titration has been examined and its effect on the accuracy of the estimated alkalinity evaluated. It is found that slope errors of the glass electrode could be a limiting factor to the accuracy that can be obtained. This error source could be eliminated altogether by applying the proposed ‘slope correction’ algorithm which uses the titration data for in situ slope calibration of the glass electrode. Application of the proposed method eliminates the need for calibration of the glass electrode and the requirement for thermostating the test solution.     

In Situ Alignment Calibration of Attitude and Doppler Sensors for Precision Underwater Vehicle Navigation: Theory and Experiment

This paper reports the development and experimental evaluation of two in situ least squares techniques for estimating the alignment matrix of Doppler sonars commonly used for precision navigation of oceanographic submersibles. Most previously reported methods addressed the problem of single degree-of-freedom heading alignment using bottom-lock Doppler sonar data and global positioning system (GPS) navigation data. This paper reports and evaluates two techniques for three degree-of-freedom calibration of attitude and Doppler sonar sensors using sensor data available to vehicles at full ocean depth. The first technique provides a general linear least squares estimate of the alignment matrix. The second technique results in a least squares alignment matrix estimate constrained to the group of rotation matrices. The performance of these estimates is evaluated with a laboratory remotely operated vehicle (ROV) and a field-deployed autonomous underwater vehicle (AUV). Experimental results are reported which demonstrate that Doppler navigation employing the reported alignment calibration techniques significantly improves navigation precision. The experiments show that the latter technique provides calibration estimates that improve Doppler navigation precision not only on the calibration data set itself, but also provide improved precision over a wide variety of vehicle trajectories other than the calibration data set.     

ADCP测量悬沙浓度的可行性分析与现场标定

根据现场观测数据，对ADCP测量悬浮沙浓度的进行标定实验。结果表明，在观测期间悬沙粒径变化较小的条件下，后散射强度与水样悬沙浓度之间存在较好的相关性。悬沙浓度剖面标定公式中的参数C′可用剖面实测水样浓度来确定，该参数与浓度密切相关：同一剖面不同浓度之间有一定的波动，但同一浓度不同潮时的变化很小。使用同一剖面参数C′的平均值计算出的剖面悬沙分布误差较大（29％－43％），而按不同深度段分别标定，误差可以小于20％，能够满足沉积动力学研究的需要。     

走航式海面遥感参数自动观测系统

配合卫星遥感数据与实测数据之校验,研制了走航式海面遥感参数自动观测系统,既满足了改善遥感数据精度的需要,又可为传统海洋学研究(海面微结构,海面温度与各种海面气象因子之间的关系等)提供大量有价值的数据,独特的自校设计,保证了数据的精度和可靠性。     

适合我国青海湖环境的全自动水文气象浮标系统

对青海湖水文气象自动观测浮标系统的背景作了简要说明，详细地介绍了该系统的总体性能指标。总结了在青海湖特定环境条件下工作的浮标系统必须解决的两项关键技术问题，给出了2000年和2001年两次青海湖现场运行过程中的部分观测数据。展望了改进后的浮标系统，用于江河湖海水文气象参数的长期连续自动观测、用于遥感卫星海上辐射校正场的广阔前景。     

FY-3A/MERSI, ocean color algorithm, products and demonstrative applications

A medium resolution spectral imager (MERSI) on-board the first spacecraft of the second generation of China’s polar-orbit meteorological satellites FY-3A, is a MODIS-like sensor with 20 bands covering visible to thermal infrared spectral region. FY-3A/MERSI is capable of making continuous global observations, and ocean color application is one of its main targets. The objective is to provide information about the ocean color products of FY-3A/MERSI, including sensor calibration, ocean color algorithms, ocean color products validation and applications. Although there is a visible on-board calibration device, it cannot realize the on-board absolute radiometric calibration in the reflective solar bands. A multisite vicarious calibration method is developed, and used for monitoring the in-flight response change and providing post-launch calibration coefficients updating. FY-3A/MERSI ocean color products consist of the water-leaving reflectance retrieved from an atmospheric correction algorithm, a chlorophyll a concentration (CHL1) and a pigment concentration (PIG1) from global empirical models, the chlorophyll a concentration (CHL2), a total suspended mater concentration (TSM) and the absorption coefficient of CDOM and NAP (YS443) from China’s regional empirical models. The atmospheric correction algorithm based on lookup tables and ocean color components concentration estimation models are described. By comparison with in situ data, the FY-3A/MERSI ocean color products have been validated and preliminary results are presented. Some successful ocean color applications such as algae bloom monitoring and coastal suspended sediment variation have demonstrated the usefulness of FY-3A/MERSI ocean color products.     

潮间带水沙多层位同步测量系统应用的初步研究

利用水压、光电转换原理研制成的多层位水沙同步测量系统(WCT系统)不仅可测量潮间带水位随时间的变化系列、同一层位的浊度及流速，还可以同步观测这些参数在潮间带水流剖面不同层位上的变化。野外对比试验表明，WCT系统获得的流速值与直读式流速仪的测量结果基本一致，平均相对误差为14．52％；悬沙传感器经野外现场率定获得悬沙浓度，平均相对误差为21．96％，精度比室内率定提高—倍以上。悬沙粒径是影响悬沙浓度测量精度的主要因素。此外，自然环境(如海水温盐度)的变化及仪器本身的特性也可能影响到测量结果。因此，WCT系统在潮间带的水位、流速和悬沙浓度的观测和边界层研究方面有相当潜力。