achael/eht-imaging
Eht Imaging
Ce projet est une suite logicielle pour l'imagerie par interférométrie radio, spécialisée dans le traitement, l'analyse et la reconstruction d'observations VLBI (Very Long Baseline Interferometry). Il fournit des outils pour reconstruire des images à partir de données d'interférométrie en utilisant des méthodes de maximum de vraisemblance régularisé et pour gérer le pipeline de traitement de bout en bout, des visibilités brutes aux images finales.
Le logiciel se distingue par un simulateur de diffusion interstellaire dédié qui modélise les effets de diffusion sur écran mince et applique des noyaux de diffusion aux images radio. Il dispose également d'un pipeline de synthèse d'images radio capable de générer des données VLBI synthétiques et d'exécuter des enquêtes paramétriques pour optimiser les configurations d'imagerie.
Le système couvre un large éventail de capacités, incluant la reconstruction d'images polarimétriques et multi-fréquences, l'étalonnage en radioastronomie et la simulation de réseaux de télescopes. Il fournit des outils d'analyse de données complets pour les distributions circulaires, l'estimation d'intervalles de confiance par bootstrap et la génération de graphiques récapitulatifs d'observation pour évaluer la fiabilité et la qualité des images.
L'ensemble d'outils prend en charge l'importation de données de radioastronomie à partir de formats tels que FITS, UVFITS et HDF5.
Features
- Interferometric Image Reconstruction - Produces radio images from interferometry data sets using regularized maximum likelihood methods.
- Interstellar Scattering Simulators - Models thin-screen scattering effects and phase fluctuations to simulate interstellar medium interference on radio images.
- Regularized Reconstruction - Produces radio images by minimizing a cost function that balances data fidelity with image smoothness.
- Multi-frequency Reconstruction - Generates images from interferometric data sets using regularized maximum likelihood methods and multi-frequency spectral indexing.
- Polarimetric Reconstruction - Produces images from radio interferometry data sets using regularized maximum likelihood methods across various polarizations.
- Pigment Scattering Simulators - Provides a specialized toolkit for modeling thin-screen scattering effects and applying scattering kernels to radio images.
- Data Processing and Analytics - Provides a system for calibrating, manipulating, and analyzing Very Long Baseline Interferometry observations and visibility data.
- Array Configurations - Configures collections of ground stations and antennas using site locations, SEFD values, and orbital elements.
- Interferometry Data Pipelines - Processes radio observations through a sequence of flagging, calibration, and tapering before image transformation.
- Interferometry Self-Calibration - Corrects observational data through self-calibration and network calibration to improve the fidelity of resulting images.
- VLBI Data Processing - Loads, calibrates, and manipulates Very Long Baseline Interferometry data sets to ensure high data accuracy and quality.
- Data Format Importers - Supports importing specialized radio astronomy formats such as FITS, UVFITS, and HDF5 into processing objects.
- Radio Calibration Tools - Loads, calibrates, inspects, and plots radio interferometry data sets and calibration tables.
- Interferometric Calibration - Corrects observation data through self-calibration and network calibration to improve the fidelity of reconstructed images.
- Radio - Offers a comprehensive suite for reconstructing astronomical images from radio interferometry data using regularized maximum likelihood.
- Astro-Image Reliability Analysis - Computes circular means, standard deviations, and bootstrap samples to evaluate the reliability of reconstructed images.
- Interferometric Visibility Representations - Stores polarimetric visibility amplitudes and phases along with source coordinates and frequency metadata.
- Interferometry Data Calibration - Corrects observation data using interpolation or extrapolation from calibration tables to ensure high data accuracy.
- Interferometry Data Pre-processing - Implements pre-imaging calibration, including site flagging, baseline rescaling, and tapering of radio observations.
- Interstellar Scattering Models - Simulates interstellar scattering by applying Fourier-domain phase fluctuations and scattering kernels to visibilities.
- Interstellar Scattering Simulation - Simulates the effects of a thin-screen scattering model using power spectra to define phase fluctuations.
- Multi-Frequency Spectral Indexing - Incorporates frequency-dependent intensity changes into the reconstruction process to produce wide-band radio images.
- Observational Dataset Generation - Calculates points and baseline uncertainties using source coordinates and station constraints to produce accurate observation sets.
- Radio Interferometry Imaging - Produces high-resolution images from radio telescope data using regularized maximum likelihood methods and spectral indexing.
- Confidence Interval Calculators - Calculates bootstrap estimates of confidence intervals for statistics, including specialized handling for circular variables.
- Parametric Survey Execution - Executes automated batches of imaging runs across predefined parameter configurations to optimize the resulting output.
- Polarimetric Sequence Synthesis - Constructs time-sequenced series of polarimetric images with defined spatial dimensions and frequency metadata.
- Astronomy - Provides a library for computing polarimetric flux, circular statistics, and bootstrap confidence intervals for astronomical data.
- Calibration Table Merging - Combines multiple calibration tables into a single dataset using specified interpolation and extrapolation settings.
- Observation Schedule Parsing - Extracts station coordinates and timing metadata from VEX schedules to define telescope array geometry.
- Imaging Pipeline Orchestration - Coordinates the loading of data files, prior image creation, and exportation of results for multiple parameter sets.
- Parametrized Command Execution - Executes batches of imaging runs by injecting different parameter sets to analyze the impact on results.
- Atmospheric Scattering - Models the impact of interstellar scattering on radio images using epsilon screens and scattering models.
- Radio Scattering Blurs - Applies a scattering kernel to an image to simulate the effect of interstellar scattering at a specific wavelength.
- Scattering Screen Synthesis - Creates a standardized Fourier representation of a scattering screen using a specified resolution and random seed.
- Polarimetric Data Generation - Generates representations of radio interferometry data including coordinates, frequency, and polarization states.
- Interferometric Deblurring - Removes interstellar scattering effects from observation data by dividing visibilities by an ensemble-average scattering kernel.
- Analytic Source Modeling - Generates geometric representations of radio sources using shapes like disks and Gaussians.
- Astronomical Observation Summaries - Produces detailed polarimetric summary plots including D-terms and fractional polarization data to evaluate image quality.
- Circular Distribution Analysis - Computes the mean and standard deviation for angular quantities to account for the wrapping nature of circular data.
- Circular Statistical Analysis - Implements specialized wrapping logic to calculate means and standard deviations for angular radio data.
- Interferometric Array Simulators - Generates synthetic interferometric data and analytic models to test detection capabilities and telescope configurations.
- Interferometric Quality Metrics - Calculates and exports chi-squared values for closure phase and visibility to evaluate reconstructed image quality.
- Interferometry Summary Plotting - Creates PDF summaries of radio interferometry images, including gain, amplitude, and closure phase consistency plots.
- Bootstrap Confidence Estimation - Provides bootstrap-based confidence interval estimation to quantify uncertainty in imaging statistics.
- Observational Data Visualization - Visualizes differences between observed data, models, and produced images through a suite of plotting tools.
- Polarimetric Radio Analysis - Generates and analyzes radio images including frequency, polarization states, and circular polarized flux over time.
- Radio Image Synthesis Pipelines - Provides a framework for generating synthetic VLBI data and executing parametric surveys to optimize imaging configurations.
- Telescope Sensitivity Normalization - Rescales gain curves using mean, median, or minimum methods to keep site sensitivities above specified thresholds.
- Time-Averaged Property Calculation - Computes derived products like visibility amplitudes and closure phases using specified averaging timescales.
- Unbiased Amplitude Estimation - Calculates the unbiased amplitude from an ensemble of Rice-distributed or visibility measurements using debiasing techniques.
- VLBI Data Simulation - Generates simulated interferometric data from existing images, including time-variable data based on real tracks.
