摘要
新研制的GPS探空仪是在我国高空站网上普遍使用的L波段雷达-数字探空仪系统中增加GPS定位模块,高空风数据不但可以通过GPS定位数据计算获得,同时还可以通过L波段雷达单测风方式进行计算,这样使其自身获得了多方面的动态比对试验。通过对23份对比施放记录分析发现:在一般情况下,经过同等的适当滑动平滑后,从L波段雷达和GPS定位两个独立系统得出的高空风廓线基本一致,说明L波段雷达的测风精度基本可以达到GPS测风水平。但在探空仪上升到高空小风速区且远离测站时,雷达测风精度明显较GPS测风精度低,需要对原始数据进行更大范围的平滑。对照分析表明:目前高空站的L波段雷达观测业务还有较大发展潜力。
GPS Sounding and Wind Measuring System （GSWMS） is a new generation of sounding system, which measures wind speed and wind direction by GPS technology. It will be the major developing trend of sounding because of positioning accuracy and characteristic of weather independent. L-band Radar and E- lectrical Radiosonde System （LRERS） has been employed widely at eighty stations. The data acquisition rate, accuracy, reliability, and automation have improved significantly. But the accuracy of LRERS meas- uring wind, the differences between its precision of measuring wind and GSWMS, and the potential of this system still needs further analysis. LRERS has designed experiments to compare 59-701 radar system with Vaisala RS-80 system. But the results are not accurate enough because of frequency interference, clock synchronization, different data processing methods and so on. In order to handle this problem, a new radiosonde with GPS function has been developed, the data of which, such as temperature, pressure, humidity, latitude, longitude and height, are received by GPS receiver through L-band radar. Real-time position and wind data are received and processed by means of L-band radar with just measuring wind at the same time. Then the wind and height data can be obtained by a strict dynamic intercomparison, due to precise time synchronization and consistent calculating methods. Thus the basic differences between these two wind profiles and compara- bility in the practical sounding application can be obtained. 23 electrical radiosondes with GPS function model has been set free which are traced by L-band radar in Shanghai and Nanjing from the last ten days of May to the first ten days of June. The analyzed result of 23 intercomparison data demonstrates that the accuracy indicators for GSWMS relative positioning is at- tained to meter grade, which can show the pendulum details of wind caused by radiosonde＇s spiral rise. The accuracy of LRERS can not reach meter grade, but it can also show the pendulum trend after handled by 3-points smoothing. Generally, after 30-point suitable smoothing to eliminate the pendulum phenome- non, two fine upper-air wind profiles from the two independent systems of LRERS and GSWMS are quite consistent when the elevation o{ radar is not too low and the radiosonde is near to the station. It reveals that the wind-finding accuracy of the LRERS may reach that of the GSWMS. However, when the balloon ascends to the high layer of low wind speed and is far away from the station, the wind measuring accuracy of the LRERS is not as good as that of GSWMS and much more smoothing is required for the original raw data from the radar. The intercomparison analysis shows that the operation of LRERS at the sounding net- work has much potential to be mined. Original location data should be explored sufficiently to provide up- per air wind data approaching GPS position.
出处
《应用气象学报》
CSCD
北大核心
2009年第2期195-202,共8页
Journal of Applied Meteorological Science
基金
科技部科学技术研究专项课题“多功能高精度GPS探空仪系统”资助
关键词
L波段雷达-数字探空仪系统
GPS定位
高空风探测
测风精度
L-band radar-digital radiosonde system
GPS location
upper air wind measurements
accuracy of measuring wind
