{"artifact_id":"L1-101","layer":"L1","title":"Active Sonar — underwater acoustic imaging","domain":"Remote Sensing","sub_domain":"Underwater acoustic imaging","physics_fingerprint":{"L_DAG":3.5,"title":"Active Sonar — underwater acoustic imaging","domain":"Remote Sensing","carrier":"acoustic","primitives":["L.emit.acoustic_pulse","S.scan.beam","L.beamform","int.temporal"],"sub_domain":"Underwater acoustic imaging","noise_model":"gaussian","problem_class":"linear_inverse","solution_space":"2D_acoustic_reflectivity","difficulty_delta":3,"integration_axis":"temporal","sensing_mechanism":"active_sonar_pulse"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 2D acoustic reflectivity 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 ~= 12); sound_speed_profile_error dominates the stability cliff; multipath 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_kHz":100,"SNR_dB":20.0,"N_beams":128,"range_m":500,"multipath":0.0,"N_range_bins":1024,"platform_roll":0.0,"sound_speed_profile_error":0.0},"input_format":"measurement_only","problem_class":"sonar_active","forward_operator":"sonar_active_forward","epsilon_fn_center":"22.0"},"omega_bounds":{"f_kHz":[10,1000],"SNR_dB":[0.0,30.0],"N_beams":[32,1024],"range_m":[10,5000],"multipath":[0.0,0.5],"N_range_bins":[256,8192],"platform_roll":[0.0,0.1],"reverberation":[0.0,0.3],"sound_speed_profile_error":[0.0,0.05]},"epsilon_bounds":{"psnr_db":[5.0,40.0]},"allowed_problem_classes":["sonar_active"],"allowed_omega_dimensions":["N_range_bins","N_beams","f_kHz","range_m","SNR_dB","sound_speed_profile_error","multipath","platform_roll","sound_speed_profile_error","multipath","platform_roll","reverberation"],"allowed_forward_operators":["sonar_active_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":3,"kappa":240,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x3ef545f9bf1b1692e3134d803e6d16b44b3343acaae994598dfe8993079f40c1","chain_tx_hash":"0x689ccee2465e89857007da46d5e087cbcb3923f68876625a032e73f9abf66b6d","chain_block":41554186}