The controller plays an important rol e in microwave landing system(MLS) navigation equipment.The embedded advanced reduced-instruction-set-computing(RISC) machine(ARM) is introduced to de velop a new MLS controller b...The controller plays an important rol e in microwave landing system(MLS) navigation equipment.The embedded advanced reduced-instruction-set-computing(RISC) machine(ARM) is introduced to de velop a new MLS controller based on the functional requirements.A design includ ing hardware and software of an ARM system is given.The hardware design involve s a ARM smallest system and its interface.μC/OS-II,a good real-time operating system(RTOS),is i ntroduced in the software design.The task partitioning and management are also i nvolved.The experimental results demonstrate that the embedded ARM technique is an effective way in the complex multi-task system,and it meets the high inte gration and real-time processing requirements of the navigation equipment.展开更多
The water and energy cycle in the Tibetan Plateau is an important component of Monsoon Asia and the global energy and water cycle. Using data at a CEOP (Coordinated Enhanced Observing Period)-Tibet site, this study ...The water and energy cycle in the Tibetan Plateau is an important component of Monsoon Asia and the global energy and water cycle. Using data at a CEOP (Coordinated Enhanced Observing Period)-Tibet site, this study presents a first-order evaluation on the skill of weather forecasting from GCMs and satellites in producing precipitation and radiation estimates. The satellite data, together with the satellite leaf area index, are then integrated into a land data assimilation system (LDAS-UT) to estimate the soil moisture and surface energy budget on the Plateau. The system directly assimilates the satellite microwave brightness temperature, which is strongly affected by soil moisture but not by cloud layers, into a simple biosphere model. A major feature of this system is a dual-pass assimilation technique, which can auto-calibrate model parameters in one pass and estimate the soil moisture and energy budget in the other pass. The system outputs, including soil moisture, surface temperature, surface energy partition, and the Bowen ratio, are compared with observations, land surface models, the Global Land Data Assimilation System, and four general circulation models. The results show that this satellite data-based system has a high potential for a reliable estimation of the regional surface energy budget on the Plateau.展开更多
文摘The controller plays an important rol e in microwave landing system(MLS) navigation equipment.The embedded advanced reduced-instruction-set-computing(RISC) machine(ARM) is introduced to de velop a new MLS controller based on the functional requirements.A design includ ing hardware and software of an ARM system is given.The hardware design involve s a ARM smallest system and its interface.μC/OS-II,a good real-time operating system(RTOS),is i ntroduced in the software design.The task partitioning and management are also i nvolved.The experimental results demonstrate that the embedded ARM technique is an effective way in the complex multi-task system,and it meets the high inte gration and real-time processing requirements of the navigation equipment.
基金the "100-Talent" Project of Chinese Academy of Sciences
文摘The water and energy cycle in the Tibetan Plateau is an important component of Monsoon Asia and the global energy and water cycle. Using data at a CEOP (Coordinated Enhanced Observing Period)-Tibet site, this study presents a first-order evaluation on the skill of weather forecasting from GCMs and satellites in producing precipitation and radiation estimates. The satellite data, together with the satellite leaf area index, are then integrated into a land data assimilation system (LDAS-UT) to estimate the soil moisture and surface energy budget on the Plateau. The system directly assimilates the satellite microwave brightness temperature, which is strongly affected by soil moisture but not by cloud layers, into a simple biosphere model. A major feature of this system is a dual-pass assimilation technique, which can auto-calibrate model parameters in one pass and estimate the soil moisture and energy budget in the other pass. The system outputs, including soil moisture, surface temperature, surface energy partition, and the Bowen ratio, are compared with observations, land surface models, the Global Land Data Assimilation System, and four general circulation models. The results show that this satellite data-based system has a high potential for a reliable estimation of the regional surface energy budget on the Plateau.