In remote sensing single-image dehazing (RSSID), adjacency effects and the multi-scale characteristics of the land surface–atmosphere system highlight the importance of a network’s effective receptive field (ERF) and its ability to capture multi-scale features. Although multi-scale hybrid models combining convolutional neural networks and Transformers show promise, the quadratic complexity of Transformer complicates the balance between ERF and efficiency. Recently, Mamba achieved global ERF with linear complexity and excelled in modeling long-range dependencies, yet its design for sequential data and channel redundancy limits its direct applicability to RSSID. To overcome these challenges and improve performance in RSSID, we present a novel Mamba-based dehazing network, U-shaped Dual Attention Vision Mamba Network (UDAVM-Net) for Satellite RSSID, which integrates multi-path scanning and incorporates dual attention mechanisms to better capture non-uniform haze features while reducing redundancy. The core module, Residual Vision Mamba Blocks (RVMBs), are stacked within a U-Net architecture to enhance multi-scale feature learning. Furthermore, to enhance the model’s applicability to real-world remote sensing data, we abandoned overly simplified haze image degradation models commonly used in existing works, instead adopting an atmospheric radiative transfer model combined with a cloud distortion model to construct a submeter-resolution satellite RSSID dataset. Experimental results demonstrate that UDAVM-Net consistently outperforms competing methods on the StateHaze1K dataset, our newly proposed dataset, and real-world remote sensing images, underscoring its effectiveness in diverse scenarios.
The Greenhouse gases Monitoring Instrument on GaoFen-5 satellite-II (GMI-II) uses spatial heterodyne spectroscopy (SHS) for quantitative monitoring of atmospheric greenhouse gases (GHG). Unlike the traditional SHS, the interferometer component of the GMI-II was designed with zero optical path difference offset, effectively improving spectral resolution while maintaining the same detector specifications. The secondary imaging system with non-isometric scaling of spatial and spectral dimensions was designed to decrease the integration time of a frame image or improve the spectral signal-to-noise ratio (SNR) under the same integration time. This paper introduces the design, manufacture, adjustment methods, and test results of the main performance indexes of the GMI-II that indicate that the spectral resolution of the O2 A-band detection channel is better than 0.6 cm−1 and other channels are better than 0.27 cm−1. Under the typical radiance of other carbon monitors’ on-orbit statistics, the spectral SNR of the GMI-II is more than 300. These test results demonstrate that the GMI-II can be well adapted to quantitative remote sensing monitoring of atmospheric GHG.
Image registration is a crucial preprocessing step in remote sensing applications, integrating information from multiple images to achieve synergistic advantages. Nevertheless, aerosols characterized by spatiotemporal heterogeneity can result in the blurring of remote-sensing images, thereby compromising the accuracy of image registration. This paper begins by analyzing the basic principles of atmospheric correction and image registration. The variations in atmospheric radiative contribution caused by aerosol changes in real-world scenarios were simulated, along with an examination of the relationship between atmospheric effects and the quantity of image features. Subsequently, addressing the challenge posed by insufficient synchronicity in aerosol parameters and the influence of atmospheric effects on remote sensing image registration, we propose a registration method based on synchronous atmospheric correction. This approach utilizes the Airborne Synchronous Monitoring Atmospheric Corrector (ASMAC) to obtain aerosol optical depth and column water vapor images for synchronous atmospheric correction of remote sensing images, along with the assessment of the registration transformation matrix. Finally, airborne experiments involving ASMAC and high-resolution cameras are conducted to validate the proposed method's improvement in remote sensing image registration accuracy. Experimental results demonstrate the effectiveness of the proposed method, showcasing an increase in the number of features and improvements in quantitative evaluation metrics. Specifically, the normalized correlation coefficient improved by up to 2.408%, while the normalized mutual information increased by a maximum of 1.395%, a maximum feature count and successfully matched features improvement of 21.1% and 38.5%
Atmospheric conditions vary significantly in terms of the temporal and spatial scales. Therefore, it is critical to obtain atmospheric parameters synchronized with an image for atmospheric correction based on radiative transfer calculation methods. On 3 July 2020, the high resolution and multimode imaging satellite, Gao Fen Duo Mo (GFDM), which was the first civilian high-resolution remote sensing satellite equipped with the Synchronization Monitoring Atmospheric Corrector (SMAC), was launched. The SMAC is a multispectral and polarization detection device that is used to retrieve atmospheric parameters that are time-synchronized with the image sensor of GFDM in the same field-of-view. On the basis of the atmospheric parameters obtained from the SMAC, a synchronization atmospheric correction (Syn-AC) method is proposed to remove the influence of the atmosphere and the adjacency effects to retrieve the surface reflectance. The Syn-AC method was applied in the experiments of synchronous atmospheric correction for GFDM images, where the surface reflectance retrieved via the Syn-AC method was compared with the field-measured values. In addition, the classical correction method, the FLAASH, was applied in the experiments to compare its performance with that of the Syn-AC method. The results indicated that the image possessed better clarity and contrast with the blurring effect removed, and the multispectral reflectance was in agreement with the field-measured spectral reflectance. The deviations between the reflectance retrievals of Syn-AC and the field-measured values of the selected targets were within 0.0625, representing a higher precision than that of the FLAASH method (the max deviation was 0.2063). For the three sites, the mean relative error of Syn-AC was 19.3%, and the mean relative error of FLAASH was 76.6%. Atmospheric correction based on synchronous atmospheric parameters can improve the quantitative accuracy of remote sensing images, and it is meaningful for remote sensing applications.
In this work, the four optimum azimuthal angles are determined for a full-Stokes scanning polarimeter comprising a rectangular prism, quarter-wave plate, and four linear polarizers. The determinant and condition numbers of the measurement matrix are used as objective functions in an optimization procedure. Illustrative examples with optimum angles and commonly used angles of linear polarizers are presented to evaluate the sensitivity of the polarimeter in estimating the incident Stokes vector, in error cases involving fluctuations in the detected flux and/or errors in the azimuthal angles of the linear polarizers. Our results show that optimum angles produce smaller errors than commonly used angles, when deriving the incident Stokes vectors.
The division of focal plane (DoFP) polarization detector has great potential for the development of aerospace polarimeters, but the existing commercial DoFP polarization detector cannot satisfy all the missions due to the diversity of satellite payloads. Here, we propose a method of directly writing a micro-polarizer array (MPA) on the detector surface based on focused ion beams (FIB) and fabricating a push-broom scanning DoFP polarization detector. The feasibility and low crosstalk of the solution were proved through testing, and the reasons for the low extinction ratio caused by oxidation were explained through characterization and numerical calculations. This scheme is not only applicable to DoFP polarization detectors but also provides ideas for the integration of other metasurface structures and detectors.