基于红边位置提取验证成像与非成像高光谱数据的一致性

Using Extraction of Red Edge Position to Validate Consistency of Hyperspectral Imaging and Non-Imaging Data

定量遥感是当前遥感发展的前沿,作物组分信息解析是农业定量遥感的研究热点,而成像高光谱技术为解决微观尺度的作物组分信息探测研究提供了强有力的手段。利用成像光谱仪(pushbroom imagingspectrometer,PIS)与地物光谱仪(FieldSpec ProFR2500,ASD)同步收集冬小麦、玉米不同生育期叶片的反射光谱,通过不同算法提取PIS与ASD数据的红边位置,验证成像光谱数据的精度。结果表明:(1)PIS与ASD原始光谱数据在红边区间(670～740 nm)有很高的吻合度;(2)从室内光谱(玉米叶片)红边位置的提取结果看,两仪器提取的红边位置都集中在700～720 nm;(3)从室外光谱(小麦叶片)红边位置的提取结果看,PIS与ASD数据提取结果有差异,PIS数据的红边位置在760 nm处,而ASD数据的红边位置在720 nm处,这种差异主要是成像光谱数据受氧气吸收的影响较大所致;(4)PIS与ASD的红边变幅不同,但趋势相同。以上结论为成像光谱数据的深入应用提供了参考。

Using Pushbroom imaging spectrometer （PIS） and FieldSpec ProFR2500 （ASD）, spectral reflectances of winter wheat and maize at different stages were collected synchronously. In order to validate the reliability of imaging spectral data, the red edge position of hyperspeetral data for PIS and ASD were extracted by different algorithms, respectively. The following results were obtained： （1） The original spectrum of both instruments had high inosculation in red light region （670~740 nm） （2） With the spectra collected under laboratory condition （maize leaf）, the extracted red edge position was is concentrated be- tween 700 and 720 nm for the two instruments; （3） With the spectra collected undre field condition （wheat leaf）, the extracted red edge position for PIS and ASD were different, the red edge position of PIS data was in 760 nm, while it was in 720 nm for ASD data. The main reason might be that the imaging spectral data were influenced by oxygen absorbtion; （4） the red edge rangeability of PIS and ASD were different, but the trends were the same. The above results could provide some references for hyperspeetral imaging data＇s extensive application.