摘要
为了提高高空大气探测数据准确度，我国从2002年1月开始推广使用L波段雷达-电子探空仪探测系统，用携带碳湿敏元件的数字式电子探空仪代替用肠膜测湿元件的59型探空仪进行相对湿度探测。但大量的实测探空资料表明：相对湿度探空曲线仍然存在较大误差。利用能测到-30℃低温的高精度湿度校准设备在-30～30℃试验温度范围内对碳湿敏元件进行大量静态测试，在进一步了解碳湿敏电阻校准线随温度变化的特征基础上，结合实际探空资料，修正工厂的相对湿度订正原理和公式，从而可以提高碳湿敏电阻在高湿端的测量准确度，提高判断云层垂直位置的准确性，进而提高L波段探空仪温度测量的精度。
The upper-air sounding data are one of the basic data synoptic situation and weather system are directly affected applied in meteorology. The analysis and forecast of by the accuracy of the data. Therefore, for the purpose of improving sounding accuracy, L-band electrical radiosonde has been employed broadly since January, 2002. Its data acquisition rate, accuracy and reliability, and the degree of automation have improved significantly since then. The new radiosonde has been implemented with carbon-film hygristor instead of Gold beaters skin hygristor to measure relative humidity. The measurement is made more accurately by the high sensitivity, short lag time, and fast response in low temperature of upper-air of carbon-film hygristor. In addition, the carbon-film has good consistency with device calibration line, which does not need to calibrate one by one. So the cost of production can be saved. The carbon-film hygristor, however, is significantly influenced by temperature. Data errors will be yielded by failure to calibrate it accurately. There are many researches on carbon-film hygristor performances but still without very encouraging results. Because of the complexity of upper-air observation, there is not a widely accepted standard to test sounding instruments＇ performances by the international community. Right now, the relative humidity data are corrected mainly by the radiosonde manufacturer. Whether the applied revising formula is reasonable or not, how is the corrected results, all need to be tested by objective analysis. However, a large number of the actual release record still shows a huge error in relative humidity sounding curve. Especially the unstable relative humidity data in the clouds which decrease strikingly with the increased altitude, and the decision of cloud location are affected directly. The accuracy of temperature detection and calculation of the geopotential height are thereby lowered. The process of correcting relative humidity data of the new L-band sounding system is described. Using the high-resolution humidity calibration equipment, many static-state testing experiments of the carbon-film hygristor are conducted at temperatures from - 30 ℃ to 30 ℃, by which a substantial amount of data is acquired. Through the test results, the various properties of this element in detail are noticed. Also a mistake in correcting formula by the manufacturers is found because of their negligence to test the influence of paralleling 1 Megohm resistance in the circuit. Based on the analysis and calculation on these lab data, the correction equation of relative humidity is re-established. The comparison and analysis of correction on real upper-air sounding data of relative humidity indicate that not only the accuracy of relative humidity data is improved after correction, but also the detailed variations in relative humidity at the upper atmosphere during high humidity range can be clearly manifested. So the ability to judge vertical position of cloud layer is improved, so is the temperature measurement precision.
出处
《应用气象学报》
CSCD
北大核心
2008年第3期356-361,共6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波段电子探空仪
碳湿敏电阻
相对湿度误差订正
L-band electronic radiosonde
carbon-film hygristor
relative humidity error correction
