松材线虫病是一种严重威胁松树生存的林业有害生物疫情。高分辨率卫星遥感技术是松材线虫病变色松木识别的有效手段。通过研究植被指数阈值法,利用2022年8月4日发射的陆地生态系统碳监测卫星(句芒号)优于2 m高分辨率4谱段相机的特点,开展基于指数的松材线虫病木识别示范,验证该卫星松材线虫病监测应用能力。基于松材线虫染病松木光谱特征,提出基于与生物量和色素相关的双指数识别策略,设计了松材线虫病指数(PWDI),并在山东省栖霞市疫区进行句芒号松材线虫病识别测试。结果表明,双指数识别策略相比单指数策略性能更优,其中PWDI与NDVI组合的松材线虫病变色松木识别能力最强,总体精度达到84.5%,NWI—NDVI,NGRDI—NDVI组合次之。在单指数策略下,PWDI的识别性仍能优于其他5个测试植被指数。研究表明,句芒号卫星具有可靠识别松材线虫病变色松木的良好潜力,松材线虫病变色松木双指数识别策略及新的识别指数PWDI可为其他类似卫星的松材线虫病监测提供借鉴。

Pine wilt disease(PWD)is a forestry pest epidemic that poses a major threat to the survival ofpine trees.High-resolution satellite remote sensing is an effective approach for identifying PWD-infected pine trees.The Terrestrial Ecosystem Carbon Inventory Satellite(Goumang Satellite),which was launched on August 4,2022,has a four-band camera with a spatial resolution of more than 2m.The purpose of this paper is to investigate the vegetation index(VI)threshold approach for demonstrating PWD detection using Goumang Satellite multispectral data.Based on the multispectral characteristics of PWD discolored pine trees,an identification strategy based on two biomass-related and pigment-related VIs is proposed and a pine wilt disease index(PWDI)is designed.A test of PWD identification was conducted in Qixia City,Shandong Province.The results demonstrated that the double-VIs identification method outperformed the single-VI strategy,with the combination of PWDI and NDVI having the best PWD recognition capacity,with an overall accuracy of 84.5%,followed by the combinations of NWI-NDVI and NGRDI-NDVI.PWDI outperformed the other five examined VIs in terms of identification performance while using a single-VI method.This research demonstrates that the Goumang Satellite has a high potential for rapid and reliable detection of PWD discolored pine trees,and that the suggested double-VIs identification technique and the new PWDI can serve as a model for other comparable satellites used for PWD monitoring.