基于全球定标场网的卫星遥感器长时间序列定标方法研究

发布时间：2018-06-14 07:56

本文选题：卫星遥感器 + 辐射定标　；参考：《中国科学技术大学》2017年博士论文

【摘要】：辐射定标是遥感信息定量化的前提和基础,其定标精度直接决定了定量遥感产品的质量。目前,我国卫星遥感器每年一次的业务化定标频次已不能满足遥感定量化应用的需求,高频次高精度的在轨绝对辐射定标已成为我国卫星遥感器迫切需要解决的问题。本文在调研了国内外各种在轨辐射定标方法的基础上,提出了一种基于全球定标场网的在轨绝对辐射定标方法,通过建立全球定标场网,增加卫星过顶次数,提高在轨辐射定标频次。论文介绍了全球定标场网定标方法的总体方案和基本流程。根据传统场地替代定标对辐射定标场地要求,以及全球定标场网的应用需求,提出了全球定标场网辐射定标场的筛选准则。通过调研全球已使用的定标场和自动化搜索定标场,收集了覆盖全球范围的131个定标场,构建了全球定标场网。同时对定标场的空间均匀性、时间稳定性、光谱形状、地表方向性和大气特性进行了分析。在构建全球定标场网的基础上,建立全球定标场网数据库,用于存储各定标场在轨绝对辐射定标所需的地表和大气参数。调研并筛选国内外可用的空基和地基业务化观测产品,为基于全球定标场网数据库提供定标基础数据,并根据各数据产品的特点,设计了相关数据存储表。为了确保全球定标场网数据库基础数据的准确性,本文用敦煌场的现场实测反射率数据对全球定标场网数据库反射率数据进行了验证,在MODIS前六个通道相对偏差不超过±3.1%。本文设计了全球定标场网辐射定标软件,用于实现全球定标场网数据库的管理和卫星遥感器的在轨绝对辐射定标。使用全球定标场网定标方法对卫星遥感器GF-1 WFV4和FY-3B VIRR分别进行了长时间序列定标,得到了 2013～2016年间的时间序列定标系数。其中GF-1WFV4的定标系数呈现出波动性;FY-3BVIRR则是单调衰变,对其绝对辐射定标系数进行线性拟合,得到了 FY-3BVIRR定标系数的日更新模型。使用传统的场地替代定标方法对GF-1 WFV4进行了在轨定标,与全球定标场网定标方法的结果进行比较,两种方法得到的绝对辐射定标系数的相对偏差小于2%,证明了全球定标场网方法的可行性和准确性。将全球定标场网定标方法的定标结果分别与官方定标结果进行比较,二者定标结果的平均相对偏差均在±5.15%以内,证明了全球定标场网定标方法具有较好的可靠性和稳定性。同时以GF-1 WFV4为例,分析了地表和大气参数对辐射定标的结果的影响。全球定标场网方法利用其短期内的高频次定标的优势,可用消除单次定标结果的偶然性,提高定标结果的可靠性和稳定性;同时利用其长时间序列的定标结果可以实现卫星遥感器的在轨辐射特性连续监测和动态跟踪,及时校正卫星遥感器的性能衰变。全球定标场网定标方法在保证定标精度的前提下显著提高定标频次,降低定标成本,提高定标时效性,为高精度的定量化遥感应用奠定了基础,具有重要的应用价值。
[Abstract]:Radiometric calibration is the precondition and foundation of remote sensing information quantification, and its calibration precision directly determines the quality of quantitative remote sensing products. At present, the frequency of the yearly calibration of satellite remote sensors in our country can not meet the needs of the remote sensing application, and the high frequency and high accuracy in orbit absolute radiation calibration has become a satellite remote sensor in our country. In this paper, based on the investigation of all kinds of on orbit radiation calibration methods at home and abroad, this paper presents an on orbit absolute radiation calibration method based on the global calibration field network. By establishing the global calibration field network, increasing the number of satellite over top number and increasing the frequency of the radiation calibration on orbit. The overall scheme and basic process of the method. According to the requirements for the radiometric calibration site and the application requirements of the global calibration field network, the selection criteria for the global calibration field network radiation calibration field are proposed. Through the investigation of the global calibration field and the automated search calibration field, 131 sets of global coverage are collected. The global calibration field network is constructed. At the same time, the spatial uniformity, time stability, spectral shape, surface orientation and atmospheric characteristics of the calibration field are analyzed. Based on the construction of the global calibration field network, a global calibration field network database is set up to store the surface and atmospheric parameters required for the absolute radiation calibration of the calibration fields. In order to ensure the accuracy of the basic data of the global calibration field network database, this paper uses the field measurement in Dunhuang field to ensure the accuracy of the basic data of the global calibration field network database. The reflectivity data of the global calibration field network database is verified. The relative deviation of the six channels in the first six channels is not more than + 3.1%.. The global calibration field network radiation calibration software is designed to realize the management of the global calibration field network database and the absolute radiation calibration of the satellite remote sensor. The global calibration field network is used. The standard method is used to calibrate the long time series of satellite remote sensor GF-1 WFV4 and FY-3B VIRR respectively, and the time series calibration coefficient of 2013~2016 years is obtained. The calibration coefficient of GF-1WFV4 is fluctuant; FY-3BVIRR is a monotonous decay, and its absolute radiation calibration coefficient is linear fitting, and the FY-3BVIRR calibration coefficient is obtained. GF-1 WFV4 is calibrated by traditional site replacement calibration method and compared with the result of global calibration field network calibration method. The relative deviation of the absolute radiometric calibration coefficient obtained by the two methods is less than 2%, which proves the feasibility and accuracy of the global calibration field network method. The calibration results of the standard method are compared with the official calibration results respectively. The average relative deviation of the two calibration results is less than 5.15%. It is proved that the global calibration field network calibration method has better reliability and stability. At the same time, the influence of the surface and atmospheric parameters on the results of radiation calibration is analyzed with GF-1 WFV4. Using the advantage of high frequency sub calibration in the short term, the standard field network can improve the reliability and stability of the calibration result by eliminating the contingency of the single calibration result and improving the reliability and stability of the calibration result. At the same time, the continuous monitoring and dynamic tracking of the satellite remote sensor can be realized by the calibration result of the long time series, and the satellite remote sensor can be corrected in time. The calibration method of global calibration field network can greatly improve the frequency of calibration, reduce the cost of calibration, improve the timeliness of calibration, and lay the foundation for high precision quantitative remote sensing application, which has important application value.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TP73

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