{"artifact_id":"L1-041","layer":"L1","title":"Photoacoustic Tomography (PAT)","domain":"Medical Imaging","sub_domain":"Hybrid optical-acoustic absorption imaging","physics_fingerprint":{"L_DAG":4.2,"title":"Photoacoustic Tomography (PAT)","domain":"Medical Imaging","carrier":"photon","primitives":["L.laser_pulse_excite","L.thermoacoustic_generation","D.ultrasound_array","int.temporal"],"sub_domain":"Hybrid optical-acoustic absorption imaging","noise_model":"gaussian","problem_class":"nonlinear_inverse","solution_space":"3D_optical_absorption","difficulty_delta":5,"integration_axis":"angular","sensing_mechanism":"photoacoustic_pa"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 3D optical absorption is guaranteed within the declared Omega bounds. Uniqueness is local rather than global (non-convex landscape); convergence depends on initialisation and priors. Stability is moderately conditioned (kappa_eff ~= 22); sound_speed_heterogeneity dominates the stability cliff; limited_view_geometry and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while TV / wavelet-sparsity / deep priors stabilise recovery at the ill-conditioned end of Omega.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"H":256,"W":256,"Z":128,"SNR_dB":22,"lambda_nm":800,"N_transducers":256,"limited_view_geometry":0.0,"laser_fluence_variation":0.0,"sound_speed_heterogeneity":0.0},"input_format":"measurement_only","problem_class":"pat","forward_operator":"pat_forward","epsilon_fn_center":"23.0"},"omega_bounds":{"H":64,"W":64,"Z":[16,512],"SNR_dB":[0.0,35.0],"lambda_nm":[650,1064],"N_transducers":[32,1024],"coupling_medium":[0.0,0.3],"limited_view_geometry":[0.0,0.6],"laser_fluence_variation":[0.0,0.3],"sound_speed_heterogeneity":[0.0,0.05]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["pat"],"allowed_omega_dimensions":["N_transducers","H","W","Z","lambda_nm","SNR_dB","sound_speed_heterogeneity","limited_view_geometry","laser_fluence_variation","sound_speed_heterogeneity","limited_view_geometry","laser_fluence_variation","coupling_medium"],"allowed_forward_operators":["pat_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":440,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x4e4dd0f446a8051c55565628c90a06acce663bfc12069182bf5d709d141507d7","chain_tx_hash":"0x32308413b53b9f8e857ad9384922297b392b984674da7f7865007cb9c255637e","chain_block":41552301}