Small object detection remains a challenge in the remote sensing field due to feature loss during downsampling and interference from complex backgrounds. A novel network, termed SEMA-YOLO, is proposed in this paper as an enhanced YOLOv11-based framework incorporating three technical advancements. By fundamentally reducing information loss and incorporating a cross-scale feature fusion mechanism, the proposed framework significantly enhances small object detection performance. First, the Shallow Layer Enhancement (SLE) strategy reduces backbone depth and introduces small-object detection heads, thereby increasing feature map size and improving small object detection performance. Then, the Global Context Pooling-enhanced Adaptively Spatial Feature Fusion (GCP-ASFF) architecture is designed to optimize cross-scale feature interaction across four detection heads. Finally, the RFA-C3k2 module, which integrates Receptive Field Adaptation (RFA) with the C3k2 structure, is introduced to achieve more refined feature extraction. SEMA-YOLO demonstrates significant advantages in complex urban environments and dense target areas, while its generalization capability meets the detection requirements across diverse scenarios. The experimental results show that SEMA-YOLO achieves mAP₅₀ scores of 72.5% on the RS-STOD dataset and 61.5% on the AI-TOD dataset, surpassing state-of-the-art models.

High-resolution nighttime light (HR-NTL) imagery is a reliable indicator of human activity in urban areas at night. However, HR-NTL images on Earth are blurred because of issues such as blooming, noise, and overexposure in the imaging system and transmission path. Toward this end, a nighttime light image deblooming network (NTL-Db-Net) is proposed, which aims to make the Earth clearer at night. The NTL-Db-Net employs a generative adversarial network (GAN) as its deblooming framework. As the lack of ideal clear NTL data for GAN training, our method integrates blur transfer algorithm to simulate degradation for generating training data. This method was tested using HR-NTL data on Wuhan, Macau, Changchun, Xiamen, Atlanta and Jerusalem from HR Jilin-1 satellite constellation. Compared with the results of state-of-the-art SEAM, Uformer, and DRBNet, those from NTL-Db-Net demonstrated superior visual features and achieved the highest scores across all selected non-reference evaluation metrics. NTL-Db-Net also exhibited a lower number of network parameters and a smaller time cost. In addition, this study conducted a spatial clustering analysis of nighttime light with road networks and permeable surfaces. The results indicated that nightlights and roads exhibited a distinct spatially aggregated distribution, while permeable surfaces displayed a clear spatially dispersed distribution. Code and data are available at https://github.com/lixinghua5540/NTL-Db-Net.

Small object detection remains a challenge in remote sensing field due to feature loss during downsampling and interference from complex backgrounds. A novel network, termed SEMA-YOLO, is proposed in this paper as an enhanced YOLOv11-based framework incorporating three technical advancements. By fundamentally reducing information loss and incorporating a cross-scale feature fusion mechanism, the proposed framework significantly enhances small object detection performance. First, the Shallow Layer Enhancement (SLE) strategy reduces backbone depth and introduces small-object detection heads, thereby increasing feature map size and improving small object detection performance. Then, the Global Context Pooling-enhanced Adaptively Spatial Feature Fusion (GCP-ASFF) architecture is designed to optimize cross-scale feature interaction across four detection heads. Finally, the RFA-C3k2 module, which integrates Receptive Field Adaptation (RFA) with the C3k2 structure, is introduced to achieve more refined feature extraction. SEMA-YOLO demonstrates significant advantages in complex urban environments and dense target areas, while its generalization capability meets the detection requirements across diverse scenarios. Experimental results show that SEMA-YOLO achieves mAP50 scores of 72.5% on the RS-STOD dataset and 61.5% on the AI-TOD dataset, surpassing state-of-the-art models.