AMSU资料监测新疆雪盖范围的初步应用

Preliminary Application of AMSU Data to the Snow Cover-Monitoring of Xinjiang

分析了沙漠、森林、草原、平原、高原地区以及水体、积雪等主要地表特征在NOAA-16AMSU(AdvancedMicrowaveSoundingUnit)对地观测最为敏感的23.8、31.4和89.0GHz通道中的光谱特性,提出了利用这3个通道监测中国新疆地区雪盖范围的方法,并得到了2001年10月到2002年3月新疆地区的旬雪盖图。AMSU监测结果与地面观测记录"点对点"的对比验证结果表明:绝大多数时间段的判识准确率在70%以上,雪盖率的变化趋势与地面观测结果也基本一致,从而确认了监测方法的可靠性及AMSU资料用于积雪监测的能力。另外,简单分析了影响AMSU监测精度的因素,并指出了需要解决的几点问题。

This paper analyzes the spectral characteristics of six major land-surfaces such as desert,forest,grassland,plain,plateau,water-body and snow-cover measured from three most sensitive 23.8,31.4 and 89.0GHz window channels of the AMSU(Advanced Microwave Sounding Unit) abroad on NOAA-16,puts forward a primary algorithm to monitor the snow-cover over Xinjiang by using the measurements from these channels,and obtains the ten-day snow-cover maps of Xinjiang from October 2001 to March 2003.The 'point to point' comparison of AMSU monitoring results with ground-based observations shows that the discrimination accuracy is about 70% or higher,and the variational trend of snow-cover percentage accords generally with ground-based observations.Both of these results prove that AMSU data are useful for snow-cover monitoring and the algorithm proposed in this paper is reliable.Besides,the paper simply analyses the factors that influence the monitoring accuracy of AMSU,and then points out several problems to be resolved in the future.