Deep Learning for Atmospheric Turbulence Mitigation: A Comparison Between GANs and Transformers
Authors: Juan S. Carrillo, Jérôme Gilles
Organizations: San Diego State University, Computational Science Research Center, Department of Mathematics and Statistics, 5500 Campanile Drive, San Diego, CA 92182, USA · San Diego State University, Department of Mathematics and Statistics, 5500 Campanile Drive, San Diego, CA 92182, USA
Atmospheric turbulence creates complex spatial and temporal distortions that significantly reduce image quality. This work compares two deep learning methods for turbulence reduction: Generative Adversarial Networks (GANs) and Transformer-based models. Both methods are trained and tested on the SOTIS dataset, which includes multi-frame sequences under different turbulence conditions with ground truth references. Our results show an important finding: GAN-based models perform better in severely degraded, low-quality situations, while Transformer-based models achieve better results in moderate to high-quality settings, especially in correcting geometric distortions. We also enhance the Turbulence Mitigation Transformer (TMT) by introducing a refined training strategy, an augmented input design that includes a temporally averaged frame as prior structural information, and a modified loss function that incorporates the Structural Similarity Index (SSIM). These improvements lead to consistent performance gains across various turbulence conditions. Overall, this study provides an in-depth evaluation of deep learning methods for turbulence reduction and offers practical guidance for selecting models in different imaging environments.
Figures & tables
Figure 1: Distribution of images in the SOTIS dataset across turbulence conditions.
Figure 2: Overview of the experimental pipeline used in this study. Starting from the SOTIS dataset, three main branches are evaluated: GAN based models, Transformer based TMT models and the MAMAT model included as an external reference method.
Figure 3: Overview of the GAN based restoration pipeline. Turbulence degraded image sequences are first stabilized and provided as input to the generator, which produces a reconstructed image.
Figure 4: Generator architecture used in the GAN model. It includes reflected edge padding, transposed convolutions, and residual blocks for stable training.
Figure 5: Discriminator architecture composed of convolutional layers and a fully connected classifier that distinguishes real (clean) from generated images.
Figure 6: Internal structure of the Transformer module. It integrates normalization, depth-wise 3D convolutions, GELU activation, residual connections, and the CTJA module shown in Fig. 7 .
Figure 7: Overview of the CTJA module. Queries, keys, and values are extracted after temporal-channel feature mixing and subsequently processed through multi-head attention.
Figure 8: Rearrangement of temporal-channel features into multiple attention heads prior to multi-head attention.
Figure 9: Overview of the TMT architecture, which processes a tensor (b, c, t, h, w) through downsampling, transformer-based encoding, and upsampling to reconstruct the input resolution.
Figure 10: Temporal sequence of n frames capturing the same scene at different times.
Figure 11: Effect of temporal averaging in reducing frame tilt and geometric distortion across multiple captures of the same scene.
Figure 12: Performance of the GAN model as a function of turbulence strength Cn2 .
Figure 13: Performance of the GAN model with respect to sensor–target distance L .
SSIM Bin
Turbulence (SSIM)
Reconstructed (SSIM)
SSIM Gain
(0–0.2]
0.1823
0.2284
0.0461
(0.2–0.3]
0.2561
0.3023
0.0462
(0.3–0.4]
0.3520
0.4058
0.0538
(0.4–0.5]
0.4506
0.5236
0.0730
(0.5–0.6]
0.5534
0.6863
0.1329
(0.6–0.7]
0.6544
0.8334
0.1790
Table 1: GAN model performance across SSIM bins. The best improvement occurs in the [0.6–0.7] range.
SSIM B
Turb
NLTV–LK
TV–LK
TV–TVL1
T.A.
NLTV–TVL1
all
(0–0.2]
0.1748
0.1606
0.1608
0.1616
0.3321
0.3326
0.2084
(0.2–0.3]
0.2577
0.2537
0.2540
0.2481
0.4142
0.4114
0.2989
(0.3–0.4]
0.3511
0.3895
0.3898
0.3585
0.5022
0.5021
0.4204
(0.4–0.5]
0.4506
0.5627
0.5630
0.5014
0.6306
0.6299
0.5795
(0.5–0.6]
0.5554
0.7611
0.7613
0.7079
0.7849
0.7848
0.7587
(0.6–0.7]
0.6525
0.8647
0.8648
0.8436
0.8694
0.8694
0.8570
Table 2: The performance of the GEN-only model across SSIM bins for different stabilization-based training configurations is shown. Each column corresponds to a GEN model trained using inputs generated by a specific stabilization method, as well as a mixed training configuration that uses all stabilization methods jointly.
Figure 14: Performance of the GEN-only model as a function of turbulence strength Cn2 using all stabilization methods.
Figure 15: Performance of the GEN-only model with respect to sensor–target distance L using all stabilization methods.
SSIM Bin
Turbulence (SSIM)
Reconstructed (SSIM)
SSIM Gain
(0–0.2]
0.1654
0.2274
0.0618
(0.2–0.3]
0.2535
0.3470
0.0934
(0.3–0.4]
0.3518
0.4681
0.1164
(0.4–0.5]
0.4529
0.5707
0.1178
(0.5–0.6]
0.5533
0.6562
0.1029
(0.6–0.7]
0.6465
0.7288
0.0824
Table 3: Original transformer model performance across SSIM bins. The strongest improvements occur in the [0.5–0.6] and [0.6–0.7] ranges.
Figure 16: Performance of the Transformer model with respect to turbulence strength Cn2 .
Figure 17: Performance of the Transformer model as a function of sensor–target distance L .
SSIM Bin
Turbulence (SSIM)
Reconstructed (SSIM)
SSIM Gain
(0–0.2]
0.1654
0.2472
0.0816
(0.2–0.3]
0.2535
0.3810
0.1274
(0.3–0.4]
0.3518
0.5323
0.1805
(0.4–0.5]
0.4529
0.7055
0.2526
(0.5–0.6]
0.5533
0.8423
0.2890
(0.6–0.7]
0.6465
0.9013
0.2548
Table 4: Modified TMT model performance across SSIM bins. The strongest improvements occur in the [0.5–0.6] and [0.6–0.7] ranges.
SSIM Bin
Turbulence (SSIM)
Reconstructed (SSIM)
SSIM Gain
(0–0.2]
0.1659
0.2485
0.0826
(0.2–0.3]
0.2539
0.3945
0.1405
(0.3–0.4]
0.3518
0.5504
0.1986
(0.4–0.5]
0.4529
0.7275
0.2746
(0.5–0.6]
0.5532
0.8670
0.3138
(0.6–0.7]
0.6464
0.9210
0.2746
Table 5: Performance of the modified TMT model with the inclusion of a temporally averaged frame (TMT-TA) across SSIM bins. The strongest improvements are observed in the mid-range SSIM bins.
Figure 18: Comparison of restoration results for the original TMT, the improved TMT, and the improved TMT with temporal average frame.
Figure 19: Generalization performance of the proposed Transformer model on an external atmospheric turbulence dataset. (a) Direct evaluation using the model trained exclusively on the SOTIS dataset. (b) Performance after transfer learning on the external dataset.
SSIM Bin
Turbulence
Direct Evaluation
Transfer Learning
SSIM Gain
(0–0.2]
0.1582
0.2612
0.3467
0.1030 / 0.1885
(0.2–0.3]
0.2577
0.3773
0.4886
0.1196 / 0.2309
(0.3–0.4]
0.3539
0.4665
0.5927
0.1125 / 0.2388
(0.4–0.5]
0.4514
0.5435
0.6791
0.0922 / 0.2277
(0.5–0.6]
0.5515
0.6197
0.7609
0.0682 / 0.2094
(0.6–0.7]
0.6508
0.6878
0.8269
0.0370 / 0.1761
Table 6: Performance of the proposed Transformer model on the external dataset.
SSIM Bin
Turbulence (SSIM)
Reconstructed (SSIM)
SSIM Gain
(0–0.2]
0.1654
0.2255
0.0433
(0.2–0.3]
0.2535
0.3133
0.0523
(0.3–0.4]
0.3518
0.4128
0.0606
(0.4–0.5]
0.4529
0.5165
0.0647
(0.5–0.6]
0.5533
0.6116
0.0565
(0.6–0.7]
0.6465
0.6945
0.0463
Table 7: MAMAT performance across SSIM bins on the SOTIS dataset.
Model
Trainable Parameters
Model Size (MB)
GAN (training)
812,434
3.10
GEN
34,929
0.13
Transformer (TMT)
22,936,370
87.50
Table 8: Architectural complexity of the evaluated restoration models.
Model
Input
Inference (ms/image)
Throughput (img/s)
GAN (training)
1×256×256
2.10
475.17
GEN
1×256×256
2.04
489.90
TMT
13×120×120
753.60
1.33
Table 9: Inference performance of the evaluated restoration models.
Figure 20: Comparison of SSIM values between the modified TMT model and the modified TMT model incorporating a temporally averaged frame across different SSIM bins. Blue bars represent the modified TMT model, while orange bars correspond to the modified TMT model incorporating the temporally averaged frame. Annotated values indicate the absolute SSIM gain introduced by including the averaged frame.
Figure 21: GEN reconstructed outputs for different stabilization methods starting from a low SSIM input, illustrating the strong dependence of reconstruction quality on stabilization choice in severe turbulence conditions.
Figure 22: Comparison of reconstructed outputs from GEN, TMT variants, and MAMAT, illustrating the superior global contrast and edge definition achieved by the Transformer based models despite occasional high SSIM values in GEN reconstructions.
Figure 23: Comparison of SSIM gains for all algorithms across different SSIM regimes
Atmospheric turbulence causes significant image degradation due to pixel displacement (tilt) and blur, particularly in long-range imaging applications. In this paper, we propose a novel framework for atmospheric turbulence mitigation, GSTurb, which integrates optical flow-guided tilt correction and Gaussian splatting for modeling non-isoplanatic blur. The framework employs Gaussian parameters to represent tilt and blur, and optimizes them across multiple frames to enhance restoration. Experimental results on the ATSyn-static dataset demonstrate the effectiveness of our method, achieving a peak PSNR of 27.67 dB and SSIM of 0.8735. Compared to the state-of-the-art method, GSTurb improves PSNR by 1.3 dB (a 4.5% increase) and SSIM by 0.048 (a 5.8% increase). Additionally, on real datasets, including the TSRWGAN Real-World and CLEAR datasets, GSTurb outperforms existing methods, showing significant improvements in both qualitative and quantitative performance. These results highlight that combining optical flow-guided tilt correction with Gaussian splatting effectively enhances image restoration under both synthetic and real-world turbulence conditions. The code for this method will be available at https://github.com/DuhlLiamz/3DGS_turbulence/tree/main.
Hanliang Du, Zhangji Lu, Zewei Cai +3
Faculty of Science and Technology, University of Macau, Macau 999078, China · College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518000, China · College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China +4
Single-frame atmospheric turbulence mitigation is inherently ill-posed due to spatially varying blur coupled with non-rigid geometric distortion. Existing end-to-end approaches trained on flat-field simulations often struggle to balance texture recovery with geometric rectification. To overcome this limitation, we propose D2Turb, a unified framework that bridges physics-grounded simulation with explicitly decoupled restoration. First, we introduce a Depth-Aware Turbulence Synthesis protocol that incorporates scene depth into the phase-to-space formulation. This generates physically consistent, depth-dependent degradations and provides a crucial intermediate tilt supervision signal for disentangled learning. Building upon this simulation engine, D2Turb decomposes restoration into two interactive stages: texture deblurring and geometric rectification. The texture deblurring stage employs a deblurring backbone to recover fine-grained details while preserving geometric distortion for the subsequent rectification stage. To mitigate the information fragmentation commonly observed in cascaded designs, we further propose an Adaptive Structural Prior Injection (ASPI) mechanism that dynamically transfers deep structural representations from the deblurring module to guide dense flow prediction for spatial unwarping. Extensive experiments demonstrate that D2Turb achieves state-of-the-art performance on both synthetic and real-world datasets, with consistent improvements in both texture recovery and geometric fidelity. Our code and pre-trained models are publicly available at https://github.com/HertzDot222/D2Turb.
Zixiao Hu, Tianyu Li, Guoqing Wang +4
University of Electronic Science and Technology of China · Beijing Institute of Space Mechanics and Electricity · School of Physics, Northwest University Xi’an
Atmospheric turbulence severely degrades video quality by introducing distortions such as geometric warping, blur, and temporal flickering, posing significant challenges to both visual clarity and temporal consistency. Current state-of-the-art methods are based on transformer, 3D architectures and require multi-frame input, but their large computational cost and memory usage limit real-time deployment, especially in resource-constrained scenarios. In this work, we propose ReMATF, a lightweight recurrent framework that restores videos using only two frames at a time while preserving spatial detail and temporal stability. ReMATF combines a multi-scale encoder-decoder with temporal warping and a motion-adaptive temporal fusion module that performs per-pixel fusion between the warped previous output and the current prediction to enhance coherence without enlarging the temporal window. This design reduces flicker, sharpens details, and remains efficient. Experiments on synthetic and real turbulence datasets show consistent improvements in PSNR/SSIM and perceptual quality (LPIPS), along with substantially faster inference than multi-frame transformer baselines, making ReMATF suitable turbulence mitigation in resource-constrained scenarios.