{"artifact_id":"L1-046","layer":"L1","title":"Doppler Ultrasound (color / spectral)","domain":"Medical Imaging","sub_domain":"Blood-flow velocity via Doppler shift","physics_fingerprint":{"L_DAG":3.2,"title":"Doppler Ultrasound (color / spectral)","domain":"Medical Imaging","carrier":"acoustic","primitives":["L.emit.acoustic_pulse","L.doppler_autocorrelation","int.temporal"],"sub_domain":"Blood-flow velocity via Doppler shift","noise_model":"gaussian","problem_class":"linear_inverse","solution_space":"2D_velocity_map","difficulty_delta":3,"integration_axis":"temporal","sensing_mechanism":"doppler_ultrasound"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 2D velocity map is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is moderately conditioned (kappa_eff ~= 10); angle_correction dominates the stability cliff; wall_filter_bleedthrough and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"f_MHz":5,"SNR_dB":22,"PRF_kHz":5,"aliasing":0.0,"depth_cm":10,"N_elements":128,"angle_correction":0.0,"wall_filter_bleedthrough":0.0},"input_format":"measurement_only","problem_class":"doppler_us","forward_operator":"doppler_us_forward","epsilon_fn_center":"24.0"},"omega_bounds":{"f_MHz":[1,15],"SNR_dB":[0.0,35.0],"PRF_kHz":[0.5,20],"aliasing":[0.0,0.5],"depth_cm":[1,25],"N_elements":[32,256],"angle_correction":[0.0,0.5],"low_velocity_sensitivity":[0.0,0.3],"wall_filter_bleedthrough":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["doppler_us"],"allowed_omega_dimensions":["N_elements","PRF_kHz","f_MHz","depth_cm","SNR_dB","angle_correction","wall_filter_bleedthrough","aliasing","angle_correction","wall_filter_bleedthrough","aliasing","low_velocity_sensitivity"],"allowed_forward_operators":["doppler_us_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":3,"kappa":200,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xd7ddf7569a81138fc26592b42a8e7866993195425b5c6627d0097f0cd9dfce57","chain_tx_hash":"0xa1a7462d4c71ae904d936f9b1c2e59a6dfe84bfb389b4d6dcb886eee36f5bdef","chain_block":41553358}