isrf
In-Flight Estimation of Instrument Spectral Response Functions Using Sparse Representations
Haouari, Jihanne El, Gaucel, Jean-Michel, Pittet, Christelle, Tourneret, Jean-Yves, Wendt, Herwig
Accurate estimates of Instrument Spectral Response Functions (ISRFs) are crucial in order to have a good characterization of high resolution spectrometers. Spectrometers are composed of different optical elements that can induce errors in the measurements and therefore need to be modeled as accurately as possible. Parametric models are currently used to estimate these response functions. However, these models cannot always take into account the diversity of ISRF shapes that are encountered in practical applications. This paper studies a new ISRF estimation method based on a sparse representation of atoms belonging to a dictionary. This method is applied to different high-resolution spectrometers in order to assess its reproducibility for multiple remote sensing missions. The proposed method is shown to be very competitive when compared to the more commonly used parametric models, and yields normalized ISRF estimation errors less than 1%.
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.04)
- North America > United States > California > Monterey County > Pacific Grove (0.04)
- Europe > Netherlands (0.04)
- Energy (0.48)
- Government (0.47)
- Transportation > Air (0.41)
Predicting the Radiation Field of Molecular Clouds using Denoising Diffusion Probabilistic Models
Xu, Duo, Offner, Stella, Gutermuth, Robert, Grudic, Michael, Guszejnov, David, Hopkins, Philip
Accurately quantifying the impact of radiation feedback in star formation is challenging. To address this complex problem, we employ deep learning techniques, denoising diffusion probabilistic models (DDPMs), to predict the interstellar radiation field (ISRF) strength based on three-band dust emission at 4.5 \um, 24 \um, and 250 \um. We adopt magnetohydrodynamic simulations from the STARFORGE (STAR FORmation in Gaseous Environments) project that model star formation and giant molecular cloud (GMC) evolution. We generate synthetic dust emission maps matching observed spectral energy distributions in the Monoceros R2 (MonR2) GMC. We train DDPMs to estimate the ISRF using synthetic three-band dust emission. The dispersion between the predictions and true values is within a factor of 0.1 for the test set. We extended our assessment of the diffusion model to include new simulations with varying physical parameters. While there is a consistent offset observed in these out-of-distribution simulations, the model effectively constrains the relative intensity to within a factor of 2. Meanwhile, our analysis reveals weak correlation between the ISRF solely derived from dust temperature and the actual ISRF. We apply our trained model to predict the ISRF in MonR2, revealing a correspondence between intense ISRF, bright sources, and high dust emission, confirming the model's ability to capture ISRF variations. Our model robustly predicts radiation feedback distribution, even in complex, poorly constrained ISRF environments like those influenced by nearby star clusters. However, precise ISRF predictions require an accurate training dataset mirroring the target molecular cloud's unique physical conditions.
- Europe > Norway > Norwegian Sea (0.24)
- North America > United States > California (0.14)
- North America > United States > Virginia > Albemarle County > Charlottesville (0.14)
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