Mazzoni Marina, Falorni Pierluigi, Verhoef Wouter
Istituto di Fisica Applicata Nello Carrara del Consiglio Nazionale delle Ricerche, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
Opt Express. 2010 Jul 19;18(15):15649-63. doi: 10.1364/OE.18.015649.
The retrieval from space of a very weak fluorescence signal was studied in the O(2)A and O(2)B oxygen atmospheric absorption bands. The accuracy of the method was tested for the retrieval of the chlorophyll fluorescence and reflectance terms contributing to the sensor signal. The radiance at the top of the atmosphere was simulated by means of a commercial radiative-transfer program at a high resolution (0.1 cm(-1)). A test data set was generated in order to simulate sun-induced chlorophyll fluorescence at the top of the canopy. Reflectance terms were spectrally modeled using cubic splines and fluorescence by means of the sum of two Voigt functions. Sensor radiance residual minimization was performed in the presence of a multiplicative noise, thus ensuring that the sensor simulations were realistic. The study, which focused on the possibility of retrieving fluorescence with an accuracy better than 10%, was performed for instrument resolutions ranging from about 0.4 cm(-1) to 2 cm(-1) in order to test the algorithm for the characteristics of existing and planned hyper-spectral sensors. The algorithm was also used to retrieve fluorescence in the single O(2)A band at the OCO and TANSO-FTS instrument spectral resolutions.
研究了在氧气的O(2)A和O(2)B大气吸收带中从太空检索非常微弱的荧光信号。对该方法用于检索对传感器信号有贡献的叶绿素荧光和反射率项的准确性进行了测试。利用商业辐射传输程序在高分辨率（0.1 cm(-1)）下模拟了大气顶层的辐射率。生成了一个测试数据集，以模拟冠层顶部太阳诱导的叶绿素荧光。反射率项通过三次样条进行光谱建模，荧光通过两个Voigt函数之和进行建模。在存在乘性噪声的情况下进行传感器辐射率残差最小化，从而确保传感器模拟是真实的。该研究聚焦于以优于10%的精度检索荧光的可能性，针对约0.4 cm(-1)至2 cm(-1)的仪器分辨率进行，以测试该算法针对现有和计划中的高光谱传感器的特性。该算法还用于在OCO和TANSO - FTS仪器光谱分辨率下检索单个O(2)A波段中的荧光。
