According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the s...According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the several key technologies for improving the performance of GEMISs,the main conclusions are as follows: the application bandwidth can be expanded by adopting flux negative feedback( 1 m Hz-10 k Hz);"laminated"core structure is useful for suppressing eddy current loss; the effective permeability of the core has increased observably after adding flux concentrators to the two ends of the core; the chopper amplifier is a useful method to suppress 1/f noise for reducing the GEMIS's output noise; the indoor calibration scheme based on"long straight solenoid"proposed to obtain sensor sensitivity. Accordingly,the problem how to reduce the noise of GEMIS is urgent need to be solved,which will improve the performance of GEMIS. And there is plenty of work requires further study on parameters ' optimization of coil and core. In the future,miniaturization,intelligence and three-axis measurement are the development directions of GEMIS.展开更多
针对GEMI(global environment monitoring index)算法和HANDS(hotspot and NDVI differencingSynergy)算法判识过火区存在的缺陷,提出了一种基于GEMI-H(GEMI and HANDS Synergy)的指数合成算法。通过利用MODIS数据进行了验证与分析,发...针对GEMI(global environment monitoring index)算法和HANDS(hotspot and NDVI differencingSynergy)算法判识过火区存在的缺陷,提出了一种基于GEMI-H(GEMI and HANDS Synergy)的指数合成算法。通过利用MODIS数据进行了验证与分析,发现新的算法不但可以减小单纯利用HANDS算法时所受到的气候条件等因子的影响,而且还融合了GEMI算法具有抗大气和土壤背景值等干扰的优点,抽取的过火区精度得到了进一步的提高。展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.41274183)the Science and Technology Department of Jilin Province(Grant No.20150520095JH)
文摘According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the several key technologies for improving the performance of GEMISs,the main conclusions are as follows: the application bandwidth can be expanded by adopting flux negative feedback( 1 m Hz-10 k Hz);"laminated"core structure is useful for suppressing eddy current loss; the effective permeability of the core has increased observably after adding flux concentrators to the two ends of the core; the chopper amplifier is a useful method to suppress 1/f noise for reducing the GEMIS's output noise; the indoor calibration scheme based on"long straight solenoid"proposed to obtain sensor sensitivity. Accordingly,the problem how to reduce the noise of GEMIS is urgent need to be solved,which will improve the performance of GEMIS. And there is plenty of work requires further study on parameters ' optimization of coil and core. In the future,miniaturization,intelligence and three-axis measurement are the development directions of GEMIS.
文摘针对GEMI(global environment monitoring index)算法和HANDS(hotspot and NDVI differencingSynergy)算法判识过火区存在的缺陷,提出了一种基于GEMI-H(GEMI and HANDS Synergy)的指数合成算法。通过利用MODIS数据进行了验证与分析,发现新的算法不但可以减小单纯利用HANDS算法时所受到的气候条件等因子的影响,而且还融合了GEMI算法具有抗大气和土壤背景值等干扰的优点,抽取的过火区精度得到了进一步的提高。