Infrared windshear prediction is one of airborne LLWS remote sensing methods.Before it is applied,the prediction system should be tested on ground to prove it’s feasibility.The LLWS simulation system isused to check ...Infrared windshear prediction is one of airborne LLWS remote sensing methods.Before it is applied,the prediction system should be tested on ground to prove it’s feasibility.The LLWS simulation system isused to check whether the infrared windshear prediction system operate properly.In this paper,according tothe requirement of the LLWS detection and the characteristic of LLWS＂source＂,we will analyze the theoryof the LLWS simulation and give a basic description of the system construction in which we pay more atten-tion to optical simulation and flight simulation.The optical simulation is used to simulate the atmospherc in-frared radiation as a LLWS occurs.The flight simulation is used to simulate the aircraft airspeed,pitch,alti-tude etc..The works presented here are necessary for the LLWS infrared prediction system.展开更多
A field experiment of nocturnal mountain wind and corresponding particulate matter （PM） evolution under weak synoptic forcing at five sites within urban Beijing was conducted using a moving Doppler wind lidar and a ...A field experiment of nocturnal mountain wind and corresponding particulate matter （PM） evolution under weak synoptic forcing at five sites within urban Beijing was conducted using a moving Doppler wind lidar and a fixed tower. Clear wind shear and zero-horizontal-wind zones at 40-320 m above the ground with a delay of 1.5 h were found at two sites between 20 km from north to south urban Beijing. The wind speed and height of the low-level jet at the north urban Beijing site were greater than those at the east urban Beijing site. The average horizontal distribution of low-level PM at 240 m was similar to the ground-level PM at night. The PM2.s （aerodynamic diameter ≤2.5 μm） accumulation center showed no abrupt changes with a shift in wind direction until the northerly wind jet arrived.展开更多
文摘Infrared windshear prediction is one of airborne LLWS remote sensing methods.Before it is applied,the prediction system should be tested on ground to prove it’s feasibility.The LLWS simulation system isused to check whether the infrared windshear prediction system operate properly.In this paper,according tothe requirement of the LLWS detection and the characteristic of LLWS＂source＂,we will analyze the theoryof the LLWS simulation and give a basic description of the system construction in which we pay more atten-tion to optical simulation and flight simulation.The optical simulation is used to simulate the atmospherc in-frared radiation as a LLWS occurs.The flight simulation is used to simulate the aircraft airspeed,pitch,alti-tude etc..The works presented here are necessary for the LLWS infrared prediction system.
基金supported by the National Natural Science Foundation of China[grant number 91544221],[grant number41571130024],[grant number 41675137],[grant number41505091]the LAPC Free Exploration Fund
文摘A field experiment of nocturnal mountain wind and corresponding particulate matter （PM） evolution under weak synoptic forcing at five sites within urban Beijing was conducted using a moving Doppler wind lidar and a fixed tower. Clear wind shear and zero-horizontal-wind zones at 40-320 m above the ground with a delay of 1.5 h were found at two sites between 20 km from north to south urban Beijing. The wind speed and height of the low-level jet at the north urban Beijing site were greater than those at the east urban Beijing site. The average horizontal distribution of low-level PM at 240 m was similar to the ground-level PM at night. The PM2.s （aerodynamic diameter ≤2.5 μm） accumulation center showed no abrupt changes with a shift in wind direction until the northerly wind jet arrived.
