低维卡尔曼滤波算法作了几何解释，这种解释对卡尔曼滤波有一种直观的理解，使人们对卡尔曼滤波有更本 质的认识。-维卡尔曼filter made of low geometric interpretation of the Kalman filter have an intuitive understanding, so that people on the Kalman filter have more understanding of the essence.