3D convolutional neural network ASPP module CNN GF-6 LiDAR Mars terrain segmentation SAR and optical images Tucker tensor decomposition UDA activation function active–passive remote sensing adapter attention mechanism attention module canopy height model (CHM) channel attention module classification closure planning cloud shadow segmentation complex-valued convolutional neural network complex-valued cross-entropy complex-valued max pooling complex-valued nonlinear activation context information context modeling convolution neural network convolutional neural network convolutional transformer cross-domain segmentation data augmentation