Light-ResKAN: A Parameter-Sharing Lightweight KAN with Gram Polynomials for Efficient SAR Image Recognition
Organizations: The authors are with the College of Electronic Science and Technology, National University of Defense Technology, Changsha, 410073, China.
Abstract
Synthetic Aperture Radar (SAR) image recognition is vital for disaster monitoring, military reconnaissance, and ocean observation. However, large SAR image sizes hinder deep learning deployment on resource-constrained edge devices, and existing lightweight models struggle to balance high-precision feature extraction with low computational requirements. The emerging Kolmogorov-Arnold Network (KAN) enhances fitting by replacing fixed activations with learnable ones, reducing parameters and computation. Inspired by KAN, we propose Light-ResKAN to achieve a better balance between precision and efficiency. First, Light-ResKAN modifies ResNet by replacing convolutions with KAN convolutions, enabling adaptive feature extraction for SAR images. Second, we use Gram Polynomials as activations, which are well-suited for SAR data to capture complex non-linear relationships. Third, we employ a parameter-sharing strategy: each kernel shares parameters per channel, preserving unique features while reducing parameters and FLOPs. Our model achieves 99.09%, 93.01%, and 97.26% accuracy on MSTAR, FUSAR-Ship, and SAR-ACD datasets, respectively. Experiments on MSTAR resized to show that compared to VGG16, our model reduces FLOPs by and parameters by . This work establishes an efficient solution for edge SAR image recognition.
Figures & tables
| Features | CNN | Transformer | KAN |
| Computational Complexity | Generally related to image dimensions and kernel size | Quadratic (with respect to sequence length) | Linear (with respect to input dimensionality), dependent on the form of activation functions |
| Parameter Efficiency | Relatively efficient via weight sharing | Parameters can be large, especially for deep or wide networks | High parameter efficiency depends on the form of the activation functions |
| Advantages | Strong visual feature extraction, relatively high computational efficiency | Powerful long-range dependency modeling, good parallelism | Low parameter count, computationally efficient, highly interpretable, strong expressive power, easy integration |
| Disadvantages | Limited global information fusion capability | High computational complexity, large parameter count, challenges in processing long sequences | Emerging field, requires extensive validation and optimization |
| Methods | Application Fields | Datasets | Activation Functions |
| KCN | Remote Sensing Scene Classification | EuroSAT | Spline |
| SpectralKAN | Hyperspectral Image Change Detection | Farmland, river, USA; Bay Area, Santa Barbara | Spline |
| WaveKAN | Hyperspectral Image Classification | Salinas, Pavia, Indian Pines | Wavelet |
| U-KAN | Agricultural Land Segmentation | South Africa Crop Type, Sentinel-1 and Sentinel-2 | Spline |
| Super-classes | Fine-classes | Number | |
| Train (17°) | Test (15°) | ||
| Rocker launcher | 2S1 | 299 | 274 |
| Air defense unit | ZSU23/4 | 299 | 274 |
| Trunk | ZIL131 | 299 | 274 |
| Bulldozer | D7 | 299 | 274 |
| Tank | T62 | 299 | 273 |
| Super-classes | Fine-classes | Number | |
| Train | Test | ||
| Ships | Cargo | 366 | 156 |
| Fishing | 248 | 106 | |
| Tanker | 150 | 64 | |
| Other ships | 312 | 133 | |
| Lands | Bridges | 1023 | 438 |
| Aircraft types | Number | |
| Train | Test | |
| A220 | 325 | 139 |
| A330 | 359 | 153 |
| A320321 | 357 | 153 |
| ARJ21 | 360 | 154 |
| Boeing737 | 370 | 158 |
| Models | Year | Pars. (M) | Size (MB) | Accuracy (%) | FLOPs (G) | Test time (ms) | ||||||
| MSTAR | FUSAR-Ship | SAR-ACD | MSTAR | FUSAR-Ship | SAR-ACD | MSTAR | FUSAR-Ship | SAR-ACD | ||||
| AlexNet [ 60 ] | 2012 | 57.04 | 228.18 | 97.44 | 89.41 | 95.76 | 0.19 | 3.71 | 0.19 | 9.54 | 30.32 | 9.53 |
| VGG16 [ 61 ] | 2015 | 134.30 | 537.21 | 96.59 | 90.73 | 96.17 | 4.07 | 80.37 | 4.07 | 11.42 | 43.72 | 11.40 |
| ResNet18 [ 62 ] | 2016 | 11.18 | 44.73 | 96.71 | 83.54 | 95.34 | 0.49 | 9.51 | 0.49 | 10.31 | 32.41 | 10.29 |
| ResNet50 [ 62 ] | 2016 | 23.53 | 94.11 | 97.13 | 86.71 | 96.69 | 1.08 | 21.35 | 1.08 | 10.92 | 32.93 | 10.91 |
| ConvNeXt [ 63 ] | 2022 | 87.58 | 350.23 | 96.04 | 77.86 | 95.83 | 4.07 | 80.53 | 4.07 | 17.23 | 53.25 | 17.19 |
| Models | Accuracy (%) | FLOPs (G) | Test time (ms) |
| AlexNet [ 60 ] | 99.38 | 15.01 | 86.31 |
| VGG16 [ 61 ] | 99.34 | 320.83 | 131.50 |
| ResNet18 [ 62 ] | 99.05 | 38.01 | 90.47 |
| ResNet50 [ 62 ] | 99.17 | 86.58 | 101.47 |
| ConvNeXt [ 63 ] | 98.76 | 321.47 | 166.58 |
| MACN [ 64 ] | 92.53 | 49.48 | 956.23 |
| K-C | G-P | B-K-C | S-A-F | MSTAR | FUSAR-Ship | SAR-ACD | |
| ResNet | 97.13 | 86.71 | 96.69 | ||||
| 96.06 | 90.44 | 95.13 | |||||
| 97.56 | 91.23 | 96.87 | |||||
| 98.22 | 91.58 | 97.07 | |||||
| 99.09 | 93.01 | 97.26 |
| Basis Functions | MSTAR | FUSAR-Ship | SAR-ACD |
| Spline Function | 96.17 | 90.45 | 93.15 |
| Chebyshev Polynomials | 93.94 | 86.04 | 92.81 |
| Legendre Polynomials | 97.33 | 91.36 | 96.94 |
| Radial Basis | 92.95 | 91.84 | 91.00 |
| Gram Polynomials | 99.09 | 93.01 | 97.26 |
| Models | MSTAR (N-Shot) | ||
| 5 | 10 | 20 | |
| AlexNet [ 60 ] | 38.48 | 46.95 | 57.64 |
| VGG16 [ 61 ] | 37.26 | 45.36 | 55.26 |
| ResNet18 [ 62 ] | 41.57 | 52.57 | 59.51 |
| ResNet50 [ 62 ] | 38.58 | 51.26 | 58.53 |
| ConvNeXt [ 63 ] | 27.36 | 38.02 | 51.37 |