TITLE: PING — deep survey
PROMPT: Build 'PING — deep survey', a sonar station on an abyssal backdrop: a central circular sonar scope (CSS/SVG rings, sweep with fading trail, blips that flare as the beam passes), depth gauge, bathymetric readouts, and a hokey-pokey dot-matrix heading tape. Around it, faint whale-song and abyss ambience optional (WebAudio oscillators, gesture-gated). Interactions: dragging inside the scope drops a marker that becomes a tracked contact with range/bearing updates, a DEPTH slider re-sonifies the scene (new contacts, different creatures in the log), and contacts clicked open an ID card with a hand-drawn-style sonar silhouette. Phosphor teal on near-black, film grain.
DESCRIPTION: A hydrographic survey station in phosphor teal on near-black with animated film grain. The circular canvas scope sweeps a fading-wedge beam; contacts flare as the beam passes then decay, tracked markers wear amber rings and tags. A dot-matrix heading tape scrolls in amber-on-teal pixels, a vertical DEPTH slider re-sonifies the whole scene across six bathymetric bands (abyssal plain to hadal trench) — swapping contacts, seafloor readouts, and the biologist's log entries. Clicking a blip or contact row opens an identification card bearing a hand-drawn-style SVG sonar silhouette (whale, dumbo octopus, wreck, trawl gear…) with range/bearing, size, and speed.
TECHNIQUES: DPR-aware canvas scope with wedge-fade sweep trail and beam-passed flare envelopes, polar coordinate contacts (bearing/range drift), canvas dot-matrix heading tape with random dead pixels for authenticity, animated grain via steps() background jitter, SVG path silhouettes with dashed frames, WebAudio sine ping with exponential decay + randomized whale moans via linearRamp (gesture-gated hydrophone toggle, default off), band-driven scene regeneration, pointer capture drag-vs-click disambiguation, prefers-reduced-motion freezes sweep/grain.
INTERACTION: The scope sweeps and logs autonomously — value is visible on load. Drag inside the scope to drop a tracked marker (ring + tag, live range/bearing in the contact list). Click any blip or contact row for its ID card and silhouette. Slide DEPTH to re-sonify: new contacts and creatures appear with a log entry. Enable HYDROPHONES for sonar pings and occasional distant whale song.