Comparison of TRMM and Water District Rain Rates over New Mexico   总被引：10，自引：0，他引：10  

Long S. CHIU  Zhong LIU  Jearanai VONGSAARD  Stanley MORAIN  Amy BUDGE  Paul NEVILLE  Chandra BALES 《大气科学进展》2006,23(1):1-13

This paper compares monthly and seasonal rain rates derived from the Version 5 (V5) and Version 6 (V6) TRMM Precipitation Radar (TPR, TSDIS reference 2A25), TRMM Microwave Imager (TMI, 2A12), TRMM Combined Instrument (TCI, 2B31), TRMM calibrated IR rain estimates (3B42) and TRMM merged gauge and satellite analysis (3B43) algorithms over New Mexico (NM) with rain gauge analyses provided by the New Mexico water districts (WD). The average rain rates over the NM region for 1998–2002 are 0.91mmd?1 for WD and 0.75, 1.38, 1.49, 1.27, and 1.07mmd?1 for V5 3B43, 3B42, TMI, PR and TCA; and 0.74, 1.38, 0.87 and 0.97 mm d?1 for V6 3B43, TMI, TPR and TCA, respectively. Comparison of V5 3B43 with WD rain rates and the daily TRMM mission index (TPR and TMI) suggests that the low bias of V5 3B43 for the wet months (summer to early fall) may be due to the non-inclusion of some rain events in the operational gauge analyses that are used in the production of V5 3B43. Correlation analyses show that the WD rain rates vary in phase, with higher correlation between neighboring WDs. High temporal correlations (>0.8) exist between WD and the combined algorithms (3B42, 3B43 and TCA for both V5 and V6) while satellite instrument algorithms (PR, TMI and TCI) are correlated best among themselves at the monthly scale. Paired t-tests of the monthly time series show that V5 3B42 and TMI are statistically different from the WD rain rates while no significant difference exists between WD and the other products. The agreements between the TRMM satellite and WD gauge estimates are best for the spring and fall and worst for winter and summer. The reduction in V6 TMI (?7.4%) and TPR (?31%) rain rates (compared to V5) results in better agreement between WD estimates and TMI in winter and TPR during summer.  相似文献   

GOCE: The Earth Gravity Field by Space Gradiometry     

Alberta Albertella  Federica Migliaccio  Fernando Sansó 《Celestial Mechanics and Dynamical Astronomy》2002,83(1-4):1-15

An artificial satellite, flying in a purely gravitational field is a natural probe, such that, by a very accurate orbit determination, would allow a perfect estimation of the field. A true satellite experiences a number of perturbational, non-gravitational forces acting on the shell of the spacecraft; these can be revealed and accurately measured by a spaceborne accelerometer. If more accelerometers are flown in the same satellite, they naturally eliminate (to some extent) the common perturbational accelerations and their differences are affected by the second derivatives of the gravity fields only (gradiometry). The mission GOCE is based on this principle. Its peculiar dynamical observation equations are reviewed. The possibility of estimating the gravity field up to some harmonic degree (200) is illustrated.  相似文献   

大气气溶胶光学厚度的卫星双通道遥感方法   总被引：6，自引：1，他引：5  

刘广员  孙毅义 《南京气象学院学报》1998,21(3):321-327

提出了一种在晴空条件下,均匀下垫面上利用ＮＯＡＡ－１４极轨卫星甚高分辨率辐射计（ＡＶＨＲＲ）可见光和近红外两个通道观测的反射率资料,遥感整层大气气溶胶光学厚度的双通道方法,该方法把气溶胶散射的波长关系加以推广,把近红外通道的光学厚度均值引入了可见通道,使单个通道中地表反射率和大气因子参数化的误差得以抵消,从而极大地提高了反演精度（〉９０％）。  相似文献   

卫星对地观测中大气与地表辐射贡献的参数化   总被引：4，自引：3，他引：1  

吕达仁  段民征 《大气科学》1998,22(4):638-648

卫星对地观测定量遥感地表与大气特性是当前地球科学与应用研究的关键手段之一。在定量遥感中区分大气和地表在地-气系统对空间散射辐射中各自的贡献与作用是关键的一步。这一问题的核心是基于辐射传输方程的数值计算建立起适合应用于遥感反演中分离大气与地表贡献的参数化表达式。本文对特定的气溶胶气候类型和可见/近红外波段建立起定量的表达形式,并对表达式的物理含义和拟合精度进行了分析。最后讨论了其应用的可行性和进一步的工作。  相似文献   

Mean Earth'S Equipotential Surface From Topex/Poseidon Altimetry     

Milan Burša  Jan Kouba  Karel Raděj  Scott A. True  Viliam Vatrt  Marie Vojtíšková 《Studia Geophysica et Geodaetica》1998,42(4):459-466

The geopotential value of W ₀ = (62 636 855.611 ± 0.008) m ² s ^–2 which specifies the equipotential surface fitting the mean ocean surface best, was obtained from four years (1993 - 1996) of TOPEX/POSEIDON altimeter data (AVISO, 1995). The altimeter calibration error limits the actual accuracy of W ₀ to about (0.2 - 0.5) m ² s ^–2 (2 - 5) cm. The same accuracy limits also apply to the corresponding semimajor axis of the mean Earth's level ellipsoid a = 6 378 136.72 m (mean tide system), a = 6 378 136.62 m (zero tide system), a = 6 378 136.59 m (tide-free). The variations in the yearly mean values of the geopotential did not exceed ±0.025 m ² s ^–2 (±2.5 mm).  相似文献   

Relationships between volcanic patterns and neotectonics in Eastern Anatolia from analysis of satellite images and DEM     

. Ad&#x;yaman  J. Chorowicz  O. Kse 《Journal of Volcanology and Geothermal Research》1998,85(1-4)

The late Neogene to Quaternary volcanism in Eastern Anatolia is related to the Arabia–Eurasia convergence but a clear deformation pattern has not yet been established in this region. We have used the distribution and shape of volcanoes and fault geometry as indicators of the tectonic regime. Volcanic edifices and related faults were analyzed in vertical view using SAR–ERS, Spot images and a Digital Elevation Model (DEM). In several places, adjacent volcanoes that form linear clusters or elongated volcanoes are clearly rooted on vertical tension fractures. These are compatible with horizontal σ₃ striking 90°N, associated with σ₁ horizontal (strike-slip regime) or vertical (extensional regime). We mapped the recent faults that are directly associated to volcanoes. Volcanic vents are related to tail-crack, horsetail or releasing bend structures. In this work, it has been possible to define the ESE-striking, 270-km-long Tutak–Hamur–Çaldiran fault that forms a releasing bend testifying to right-lateral motion. Extension is well documented for few places but no recent fold has been observed. Since 8 Ma, the tectonic system is principally strike-slip. Most of the tension fractures being 2 to 10 km in length, so we infer that they affect only part of the crust. Most strike-slip fault zones are of several tens to a few hundred kilometers long and thus not of lithospheric scale. Therefore, the channels used by the magma to reach the surface are crustal structures.  相似文献   

应用遥感技术连续监测地表土壤含水量   总被引：9，自引：2，他引：9       下载免费PDF全文

陆家驹  张和平 《水科学进展》1997,8(3):281-287

根据地表湿度与地表温度之间的关系,以及气温变化对这种关系的影响分析,经过气象卫星热红外波段信息与地表温度的有效转换,建立起一个连续监测地表土壤含水量的遥感模型。该模型只需无云条件下的白天气象卫星资料,综合考虑了各种植被覆盖条件,所以模型操作简单、易于推广,具有大范围监测土壤含水量的实用性。  相似文献   

“93·8”中尺度对流复合体的云图分析   总被引：4，自引：1，他引：4  

刘玉芝  邹树峰  王广春 《气象》1996,22(12):20-23

１９９３年８月４－５日在副热带高压北－西北边缘发生了一个很强的中尺度对流复合体，该文应用ＧＭＳ－４红外卫星云图分析了它的发生和发展。  相似文献   

中国气象局VSAT卫星通信系统     

徐建平  龚理藩  吴贤伟 《气象》1996,22(2):12-17

叙述了中国气象局ＶＳＡＴ卫星通信系统的总体结构和布局、主要功能、配置以及对外服务的方式。该系统将是中国气象局的主要通信系统，由主站和３６０个ＶＳＡＴ小站组成，能完成气象部门的数据通信和话音通信。还能为其它用户提供服务。  相似文献   

日本GMS扫描云图定位的自适应校准     

李凤昌 《气象》1996,22(8):46-48

在对ＧＭＳ系列卫星云图进行定位时，由于种种原因，有时会出现偏差，该文给出了消除偏差的自适应校准方法。  相似文献