arXiv AI

Physics-Informed Neural Networks for Fast Multilayer Spectral Inversion of H{\alpha} 6562.8 A and Ca II 8542.1 A Spectra

The paper presents a physics-informed neural network (PINN) that accelerates multilayer spectral inversion (MLSI) of solar chromospheric lines Hα 6562.8 Å and Ca II 8542.1 Å. The PINN predicts MLSI parameters from observed line profiles and uses a differentiable forward model to synthesize spectra, trained in two stages—first with spectral reconstruction loss, then fine‑tuned with conventional MLSI results on a single reference image. Applied to Fast Imaging Solar Spectrograph data, the method reproduces key spatial structures and achieves a 12–60× speedup, processing a raster in 5–15 s versus 3–5 min for traditional MLSI.

arXiv Machine Learning
Aug 11

Real-time physics inversion for retrieval of sub-pixel wildfire temperatures from VSWIR imaging spectroscopy

arXiv:2608. 07580v1 Announce Type: cross Abstract: In this work, we present a wildfire temperature retrieval framework for VSWIR imaging spectroscopy data, employed on data from NASA's Airborne Visible Infrared Imaging Spectrometer (AVIRIS-3).

By William R. Keely, Philip G. Brodrick, Katherine Mistick, Adam Chlus, Robert O. Green, Philip E. Dennison
arXiv Machine Learning
Aug 27

Tropospheric temperature and humidity profile retrieval from Meteosat Flexible Combined Imager based on deep learning

The study presents a spatially aware deep learning framework that retrieves all‑sky tropospheric temperature and humidity profiles from the Meteosat Third Generation Flexible Combined Imager (FCI) without relying on numerical weather prediction background fields. Using a Residual U‑Net trained on 14 months of collocated FCI observations and CERRA reanalysis data, the model achieves temperature biases below 0.4 K and relative humidity standard deviations between 12–20 %, with modest performance degradation under cloud cover. Ablation and feature‑sensitivity analyses confirm that incorporating spatial context across all 16 FCI channels, including visible and near‑infrared bands, improves retrieval accuracy, especially beneath cloud tops.

By Alejandro Salgueiro, Johannes Rausch, Julie Th\'er\`ese Villinger, Angela Meyer
arXiv Machine Learning
Jun 24

Efficient reduction of stellar contamination and noise in planetary transmission spectra using neural networks

arXiv:2602. 10330v3 Announce Type: replace-cross Abstract: Context: The characterization of exoplanetary atmospheres has been transformed by the James Webb Space Telescope (JWST), whose infrared sensitivity enables transmission spectroscopy at unprecedented precision.

By David S. Duque-Casta\~no, Lauren Flor-Torres, Jorge I. Zuluaga
arXiv Machine Learning
Aug 18

Efficient Neural-Network-Based High-Resolution Radiative Transfer for CO___ Retrieval, and Application to Interferometric Sensing

arXiv:2608. 14645v1 Announce Type: new Abstract: Studying climate change requires reducing uncertainties in CO2 and CH4 emission estimates to better distinguish anthropogenic from natural sources, which motivates spaceborne measurements with improved revisit frequency and spatial coverage.

By Jordan Lontsi Tedongmo (CB), Yann Ferrec (CB, IFUMI), Laurence Croiz\'e (CB, IFUMI), Pablo Mus\'e (CB, IFUMI), Gabriele Facciolo (CB), Andr\'es Almansa (MAP5 - UMR 8145, IFUMI)
arXiv AI
Sep 12

Physics-Informed Neural Networks to Infer the Perpendicular Energy Conductivity in the Scrape-Off Layer of Stellarator Devices

The paper presents an inverse Physics-Informed Neural Network (PINN) framework that infers the scrape‑off layer (SOL) perpendicular heat conductivity κ_π(n,T) from radial electron density and temperature measurements combined with a reduced one‑dimensional transport equation. Three neural networks are trained simultaneously: two reconstruct the temperature and density profiles, while the third models the conductivity as a function of local density and temperature. The method is validated on synthetic data, achieving errors below 10 % in the data‑constrained region, and is then applied to experimental data from the TJ‑II stellarator using a helium‑beam diagnostic to estimate the effective SOL conductivity.

By J. Gallego (Departamento de Tecnolog\'ia, CIEMAT, Spain), P. Protopapas (Harvard John A. Paulson School of Engineering and Applied Sciences, USA), A. Bustos (Departamento de Tecnolog\'ia, CIEMAT, Spain), A. Alonso (Laboratorio Nacional de Fusi\'on, CIEMAT, Spain), S. Barquero (Laboratorio Nacional de Fusi\'on, CIEMAT, Spain), A. Baciero (Laboratorio Nacional de Fusi\'on, CIEMAT, Spain), I. Rivera (Laboratorio Nacional de Fusi\'on, CIEMAT, Spain), J. A. Mor\'i\~nigo (Departamento de Tecnolog\'ia, CIEMAT, Spain), R. Mayo-Garc\'ia (Departamento de Tecnolog\'ia, CIEMAT, Spain)
arXiv Computer Vision
Sep 7

Learning Spatial-Spectral Refinement and Calibrating Complementary Observations for Hyperspectral Image Super-Resolution

The paper introduces TSR-ITNR, a two‑stage, self‑supervised framework for hyperspectral image super‑resolution that fuses high‑resolution multispectral and low‑resolution hyperspectral data. Stage 1 refines an implicit Tucker representation using a low‑rank spatial tensor and spectral basis, enhanced by a pretrained denoiser, to capture fine spatial details and spectral correlations. Stage 2 applies parameter‑free calibration to extract complementary corrections from both observations, preserving geometry and ensuring orthogonal complementarity, leading to superior reconstruction quality demonstrated on benchmark datasets and improved downstream segmentation performance.

By Liqian Yang, Xingchi Chen, Xinfeng Gui, Xiangyong Cao, Qianxin Yi
arXiv Machine Learning
Sep 25

Image Fidelity is Not Field Fidelity: Joint Thermodynamic Reconstruction and Error Localization in Neural Tomography

The paper introduces CoroNeRF, a method that jointly optimizes 3D electron density and temperature fields from multi‑view, multi‑line solar coronal tomography data using a differentiable atomic‑emission renderer. It demonstrates that low 2D image error does not guarantee accurate 3D field reconstruction, and that cross‑seed instability can rank local field errors without ground truth. The study highlights the limitations of image fidelity as a proxy for field fidelity and evaluates seed‑based error localization in a controlled solar tomography setting.

By Alan Hsu, Jenna Samra, Alin Razvan Paraschiv, Liam Connor
arXiv Machine Learning
Jun 10

An adaptive framework for the axisymmetric pulsar magnetosphere using physics-informed Kolmogorov-Arnold networks

arXiv:2606. 10686v1 Announce Type: cross Abstract: The pulsar magnetosphere has only recently been addressed using Physics-Informed Neural Networks (PINNs), by deploying a domain-decomposition approach and treating the separatrix and equatorial current sheet as infinitesimally thin discontinuities.

By Spyros Rigas, Ioannis Contopoulos, Georgios Alexandridis, Antonios Nathanail