简介：TheseasonalvariabilityofcloudopticaldepthovernorthwesternChinaderivedfromCloudsandtheEarth'sRadiantEnergySystem(CERES)SingleScannerFootprint(SSF)AquaModerateResolutionImagingSpectroradiometer(MODIS)Edition1BdatafromJuly2002toJune2004ispresented.TheregionsofinterestarethosewithAsiamonsooninfluence,theTianshanandQilianMountains,andtheTaklimakanDesert.TheresultsshowthattheinstantaneousmeasurementspresentedherearemuchhigherthanthepreviousresultsderivedfromInternationalSatelliteCloudClimatologyProject(ISCCP)D2monthlymeandata.Generallythemeasurementsofcloudopticaldeptharethehighestinsummerandthelowestinwinter,however,TaklimakanDeserthasthelowestmeasurementsinautumn.TheregionalvariationisquitesignificantovernorthwesternChina.

简介：当microsatellite技术发展，精确内部卫星的测量在分布式的卫星系统显示出它的意义。在这封信，一种新奇技术为测量内部卫星的距离被建议，它采用optoelectronic回声并且有功能自我引用。回声洞有高度光谱纯净和高摆动频率。由利用积聚的扩大原则把距离的测量变换成频率的，高精确性被完成。在实验，这个测量计划有在1和6km之间的一个大测量范围(能潜在地更大)，并且精确性比1.5m好。相对精确性到达1010的水平。