From 5d1b6262813e1dc57b51ad7bd5ec6f42827490e6 Mon Sep 17 00:00:00 2001 From: Mark Allyn Date: Tue, 21 Apr 2026 08:38:18 -0700 Subject: [PATCH] add descriptions --- CLAUDE.md | 240 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) diff --git a/CLAUDE.md b/CLAUDE.md index cc31847..687d40e 100644 --- a/CLAUDE.md +++ b/CLAUDE.md @@ -641,3 +641,243 @@ settings.h — tunable constants: - Rain clutter filter: default (0.0 = off), minimum (0.0), maximum (1.0), keyboard step size - Wave clutter filter: default (0.0 = off), minimum (0.0), maximum (1.0), keyboard step size - Key-hold acceleration for gain, rain clutter, and wave clutter keys + +================================================================== + +LEFT PANEL TEXT — ONE ENTRY PER SCOPE + +================================================================== + +Note: Each left panel renders its description text followed immediately by its +control table. Every panel also states the next scope name so the visitor knows +what pressing s will show. The s / S advance note appears in every panel. + +------------------------------------------------------------------ +PANEL 1 — EXHIBIT INTRODUCTION +------------------------------------------------------------------ + +Header (all caps, large): + WELCOME TO THE MUSEUM VINTAGE RADAR EXHIBIT + +Body: + Welcome! This exhibit lets you experience how radar worked from the 1940s + through the 1960s — technology that changed the course of World War 2 and + shaped modern aviation and maritime safety. + + Radar works by sending out short bursts of radio energy and listening for + the echo that bounces back from ships, aircraft, and terrain. By measuring + the time it takes for the echo to return, the radar calculates how far away + the object is. Rotating the antenna builds a map of everything around it. + + This exhibit features six radar displays. Explore each one at your own pace. + + Press s at any time to jump to the next display — do not wait for the + automatic 120-second advance. Press S (shift+s) to go back. + Pressing any key or control resets the 120-second timer. + + Next: Marine A-Scope → + + ┌─────┬───────────────────────┐ + │ KEY │ FUNCTION │ + ├─────┼───────────────────────┤ + │ s │ Next display │ + │ S │ Previous display │ + └─────┴───────────────────────┘ + +------------------------------------------------------------------ +PANEL 2 — MARINE A-SCOPE +------------------------------------------------------------------ + + The A-Scope was one of the earliest radar displays, used aboard ships and + in coastal stations in the 1950s. Unlike the circular display you may have + seen in movies, the A-Scope sweeps left to right: distance (range) runs + along the bottom axis, and the height of each spike shows how strong the + echo is from that direction. + + To look in a different direction, the operator physically rotates the + antenna by hand. Use c and v to rotate the antenna on this display. + + The green glow is the P1 phosphor coating on the inside of the cathode ray + tube. In a real radar room this was often the only light in the space. + + The glass panel in front of the screen is the graticule — an etched, + back-lit calibration scale for measuring range. When you change the maximum + range setting, watch the operator swap the graticule panel by hand — just + as it was done in the period. + + Location: Bellingham Bay, WA — a fictional 100-foot mid-bay platform. + + Press s to advance. Press S to go back. Auto-advance in 120 seconds. + Any key press resets the timer. Next: Chain Home A-Scope → + + ┌──────┬──────────────────────────────┐ + │ KEY │ FUNCTION │ + ├──────┼──────────────────────────────┤ + │ s/S │ Next / previous scope │ + │ c/v │ Bearing clockwise / CCW │ + │ u/d │ Max range up / down (2,4,6) │ + │ 1/2 │ Gain increase / decrease │ + │ 3/4 │ Rain filter increase / dec │ + │ 5/6 │ Wave filter increase / dec │ + └──────┴──────────────────────────────┘ + +------------------------------------------------------------------ +PANEL 3 — CHAIN HOME A-SCOPE +------------------------------------------------------------------ + + Chain Home was Britain's early warning radar network, built in the late + 1930s and critical during the Battle of Britain (1940). Instead of a + rotating dish, it used a fixed array of tall transmit towers that flooded + the sky over the English Channel with radio energy — a technique called + floodlighting. Aircraft crossing the Channel reflected this energy back + to separate receive antennas, sometimes at ranges up to 100 miles. + + FINDING DIRECTION — THE GONIOMETER + Because there was no rotating dish, finding the bearing and altitude of a + target required a technique called nulling. A device called a goniometer + electronically combined signals from several receive antennas. The operator + slowly turned the goniometer dial while watching the screen. In most + positions the signal was strong. But at one precise setting the signal + suddenly disappeared — this was the null. When nulled, the goniometer was + pointing directly at the aircraft. Think of it like tuning a radio: you + search for the silent spot between two stations. Press [ to switch the + goniometer between bearing (horizontal) and elevation (vertical) modes. + Use keys 9 and 0 to tune — turn slowly, the null appears suddenly. + + CALIBRATOR PIPS + Early electronics drifted, stretching or compressing the range scale. + The crystal calibrator injects tiny spikes at exact 10-mile intervals. + Use n to shrink and m to stretch the trace until the pips line up with + the 10-mile marks on the glass graticule. + + This display is set at the Chain Home station at Poling, East Sussex, + facing the English Channel. All targets are simulated German aircraft. + + Press s to advance. Press S to go back. Auto-advance in 120 seconds. + Any key press resets the timer. Next: Marine PPI → + + ┌──────┬─────────────────────────────────┐ + │ KEY │ FUNCTION │ + ├──────┼─────────────────────────────────┤ + │ s/S │ Next / previous scope │ + │ [ │ Goniometer mode: bearing / elev │ + │ 9/0 │ Goniometer tune left / right │ + │ . │ Toggle PRF: 25 Hz / 12.5 Hz │ + │ n/m │ Calibrator shrink / stretch │ + │ 1/2 │ Gain increase / decrease │ + │ 3/4 │ Rain filter increase / dec │ + │ 5/6 │ Wave filter increase / dec │ + └──────┴─────────────────────────────────┘ + +------------------------------------------------------------------ +PANEL 4 — MARINE PPI SCOPE +------------------------------------------------------------------ + + The PPI (Plan Position Indicator) became the standard radar display for + ships from the late 1950s onward. The antenna rotates clockwise and the + sweep line rotates with it, painting a map of everything within range. + Targets glow bright blue the instant the sweep passes over them, then + fade through green to yellow before the sweep returns — this is the P7 + phosphor persistence that keeps the picture visible between sweeps. + + The dotted range rings give distance reference. The incandescent bearing + scale shows True direction (0 = North, clockwise to 359). + + The yellow overlay is a mechanical cursor — a plastic ring and crosshair + mounted in front of the screen. Use the cursor keys to position it over a + target; range and bearing read out below the scope. + + Location: Bellingham Bay, WA — a fictional 100-foot mid-bay platform. + Targets: AIS-equipped vessels and simulated traffic. + + Press s to advance. Press S to go back. Auto-advance in 120 seconds. + Any key press resets the timer. Next: ATC PPI → + + ┌──────┬────────────────────────────────────┐ + │ KEY │ FUNCTION │ + ├──────┼────────────────────────────────────┤ + │ s/S │ Next / previous scope │ + │ u/d │ Max range up / down (2, 4, 6 mi) │ + │ r/l │ Cursor bearing right / left │ + │ t/y │ Cursor range increase / decrease │ + │ k/j │ Antenna offset right / left │ + │ │ (boat heading correction — zero │ + │ │ means antenna faces True North) │ + │ 1/2 │ Gain increase / decrease │ + │ 3/4 │ Rain filter increase / decrease │ + │ 5/6 │ Wave filter increase / decrease │ + └──────┴────────────────────────────────────┘ + +------------------------------------------------------------------ +PANEL 5 — AIR TRAFFIC CONTROL PPI SCOPE +------------------------------------------------------------------ + + This is the Airport Surveillance Radar (ASR) display used by air traffic + controllers at regional airports in the 1960s. It works on the same + principle as the marine PPI but covers a larger area (up to 20 miles) and + is optimised for tracking aircraft rather than ships. The S-Band frequency + (3 GHz) gives a good balance of range, resolution, and resistance to + weather clutter for airspace surveillance. + + Controllers used this display to sequence arriving and departing aircraft, + identify potential conflicts, and provide navigation guidance to pilots + flying in low visibility conditions. + + Location: Bellingham International Airport (BLI), dedicated radar tower. + Targets: ADS-B equipped aircraft and simulated traffic. + + Press s to advance. Press S to go back. Auto-advance in 120 seconds. + Any key press resets the timer. Next: Precision Approach Radar → + + ┌──────┬──────────────────────────────────────────┐ + │ KEY │ FUNCTION │ + ├──────┼──────────────────────────────────────────┤ + │ s/S │ Next / previous scope │ + │ u/d │ Max range up / down (5, 10, 15, 20 mi) │ + │ r/l │ Cursor bearing right / left │ + │ t/y │ Cursor range increase / decrease │ + │ k/j │ Antenna offset right / left │ + │ 1/2 │ Gain increase / decrease │ + │ 3/4 │ Rain filter increase / decrease │ + └──────┴──────────────────────────────────────────┘ + +------------------------------------------------------------------ +PANEL 6 — PRECISION APPROACH RADAR (PAR) +------------------------------------------------------------------ + + The Precision Approach Radar was developed during World War 2 and refined + through the 1950s. It gives a controller a precise picture of exactly where + an aircraft is on its final approach to the runway — both its left-right + position and its altitude. + + Unlike instrument landing systems that require special equipment on the + aircraft, PAR needed nothing from the pilot's plane. The controller watched + the display and talked the pilot down over the radio: "You are slightly + right of centerline, begin correcting left. You are above the glide path, + begin a slightly steeper descent." This made PAR invaluable when a plane's + own instruments failed or when visibility dropped to near zero in heavy fog. + + TOP DISPLAY — AZIMUTH (left-right) + Shows whether the aircraft is left or right of the runway centerline. + The centerline runs horizontally through the middle of the display. + + BOTTOM DISPLAY — ELEVATION (up-down) + Shows whether the aircraft is above or below the correct glide slope. + The ideal descent path runs through the center of the display. + + Both displays expand the inner 5 miles to 70% of the screen width — + giving maximum precision during the critical final approach phase. + + Location: South end of Runway 16/34, Bellingham Airport (BLI). + Active runway: 34 (aircraft landing northbound). All traffic is simulated. + + Press s to advance. Press S to go back. Auto-advance in 120 seconds. + Any key press resets the timer. Next: Exhibit Introduction → + + ┌──────┬──────────────────────────────┐ + │ KEY │ FUNCTION │ + ├──────┼──────────────────────────────┤ + │ s/S │ Next / previous scope │ + │ 1/2 │ Gain increase / decrease │ + │ 3/4 │ Rain filter increase / dec │ + └──────┴──────────────────────────────┘