Geostationary satellites collect high-resolution weather data comprising a series of images which can be used to estimate wind speed and direction at different altitudes. The Derived Motion Winds (DMW) Algorithm is commonly used to process these data and estimate atmospheric winds by tracking features in images taken by the GOES-R series of the NOAA geostationary meteorological satellites. However, the wind estimates from the DMW Algorithm are sparse and do not come with uncertainty measures. This motivates us to statistically model wind motions as a spatial process drifting in time. We propose a covariance function that depends on spatial and temporal lags and a drift parameter to capture the wind speed and wind direction. We estimate the parameters by local maximum likelihood. Our method allows us to compute standard errors of the estimates, enabling spatial smoothing of the estimates using a Gaussian kernel weighted by the inverses of the estimated variances. We conduct extensive simulation studies to determine the situations where our method performs well. The proposed method is applied to the GOES-15 brightness temperature data over Colorado and reduces prediction error of brightness temperature compared to the DMW Algorithm.
翻译:地球静止卫星收集高分辨率气象数据,其中包括一系列图像,可用于估计不同高度的风速和风向。衍生动力风(DMW)算法通常用于跟踪NOAA地球静止气象卫星GOES-R系列所摄图像中的特征,从而处理这些数据和估计大气风。然而,DMW Algorithm的风量估计数据稀少,没有采取不确定措施。这促使我们从统计角度对风力运动进行模拟,作为空间过程在时间上漂移的一种空间过程。我们提议了一个取决于时空滞后和漂移参数的共变函数,以捕捉风速和风向。我们用当地最大可能性估算参数。我们的方法使我们能够计算估计数的标准误差,利用按估计差异反数加权的高山内核对估计数进行空间平滑。我们进行了广泛的模拟研究,以确定我们的方法在哪些情况下表现良好。我们提议的方法适用于科罗拉多州GES-15的亮度温度数据,并减少与DMWALgorim相比的亮度温度预测误差。