continue with specification

CLAUDE.md

@@ -41,8 +41,6 @@ Use // for single line comments
 use /* */ for multiple block comments spanning multiple lines
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-_______________________________________________________
-
 Summary of project:
 
 This is a museum exhibit displaying and providing interaction
@@ -53,16 +51,152 @@ radars in that era. The different radars are:
 Scopes in the right panel
 
 1. A-scope for Chain Home Radar in the 1940's (first radar and could be tricky)
-2. A-scope for marine radar in the 1950's (Before PPI radar. Was a bit tedious to operate
+2. A-scope for marine radar in the 1950's (Before PPI radar); was a bit tedious to operate
 3. PPI scope for marine traffic control (uses beam sweeping in all 360 degrees of
-   rotation; Easier to use than a scope
+   rotation); Easier to use than a scope
 4. PPI scope for air traffic control; similar to PPI scope for marine, but with different range
 5. PPI scope on board a boat. Shows how movement of a boat affects the radar display
 6. Precision Approach Radar (Two scopes; one showing horizontal movement of a plane
    in the glide path toward the runway, and the other showing vertical movement of a plane
-   as it glides vertically down to the runway.
+   as it glides vertically down to the runway). Both scopes will be seen if this is selected.
 
-Text window in the left panel for descriptions of the scopes and a listing of controls
+Please note that these scopes will not appear all at once. The selection of which scope
+the visitor sees is done by pressing a forward control and a reverse control to go around
+the loop of scopes.
+
+Also, please note that the state of the controls of each scope is independent of any
+other scope. Furthermore, the controls will reset when a scope is exited and then re-entered.
+
+The Text window in the left panel for descriptions of the scopes and a listing of controls
 
 Controls to affect the behavior of the scopes; (these first implemented using keyboard
-strokes; later when physical controls are completed, the keyboard controls will be removed.
+strokes; later when physical controls are completed, the keyboard controls will be removed)
+
+The controls will affect state variables that will be sent to the shaders as uniforms. 
+
+There will be three abstracts for scopes:
+
+1. A Scope - sweep on horizontal axis. A pulse will appear for a return. The distance from
+   the left hand side to the pulse is the range. The height of the pulse is the strength
+   of the return signal. The bearing is determined by manual control.
+
+   The basic controls for both A Scopes include:
+      Intensity (the overall brightness of the entire display).
+      Sensitivity (the strength of the signal amplification of the
+      receiver). This has nothing to do with the brightness of the
+      pulses. This only affects the height of the pulse and the height
+      of any noise floor.
+
+   Chain Home A Scope
+
+   Because the receiving antennas are very large (about 100 feet), the
+   operator cannot physically move them. 
+       
+   Therefore, the bearing is determined through a process called radio direction
+   finding (RDF) using a specialized instrument known as a Radiogoniometer.
+
+   The receiver towers (which were separate from the transmitter towers) 
+   featured two sets of dipole antennas mounted at right angles to one 
+   another—essentially one oriented North-South and the other East-West.
+
+   The signals from these two perpendicular antennas were fed into a Radiogoniometer
+   located in the receiver hut. Inside the device there are two fixed coils (field coils)
+   that were mounted at right angles matching the orientation of the outdoor antennas.
+   A third coil, the search coil, is mounted on a rotating shaft inside the two 
+   field coils. The operator would physically turn a knob to rotate the search coil.
+
+   The relative strength of the signal in each antenna depended on the angle of the
+   incoming wave. For example, a target directly to the North would produce a maximum
+   signal in the North-South antenna and zero in the East-West antenna. 
+
+   The operator would look for a null point (a signal or pip weaker than the noise floor).
+   At that point, the operator would read the bearing from a calibrated scale attached
+   to the radiogoniometer knob.
+
+   We can simulate the radiogoniometer knob that would affect the null point depending
+   on the bearing of a target. The museum visitor could experience seeing different
+   null points for each target. Since we do not have a physical calibrated knob, we
+   can put the bearing as a text indicator below the A Scope.
+
+   The range is 200 miles.
+
+   There is also a selection for the pulse repetition frequency (PRF). A switch was
+   used to select one of two PRFs. One is 50 pulses per second and the other is 25
+   pulses per second. This selection should also be indicated in the status text
+   below the scope. We need to have a keyboard selection to cycle this selection
+   as well as a switch on the control panel.
+
+   There is a glass or plastic graticule that is etched with vertical lines
+   representing range. This is edge-lit with incandescent lamps.
+
+   Because of natural drift of period electronic components, they needed an
+   electronic calibration, or strobe. 
+
+   This is a crystal oscillator which is
+   steady and precise. 
+
+   The pip generated by this circuit can be moved via knob or keyboard keys and
+   its position is indicated on the text status line below the scope.
+   The operator aligns this pip with a target pip in order to get an accurate
+   range to the target.
+
+   Marine A Scope
+
+   Marine radar frequencies allowed the use of much smaller antennas;
+   dishes or horns. Those antennas would be mounted on the shaft of a servo motor. The
+   servo motor would be driven by another servo that is attached to the bearing control
+   knob on the radar console. The bearing is on a calibrated dial on the bearing control
+   knob.
+
+   We can simulate the bearing knob that would affect the simulated pointing of the
+   dish antenna. The museum visitor could experience seeing different
+   pips appear as they rotate the antenna toward them. Likewise the pips would disappear
+   as the antenna is rotated away.
+
+   The range is indicated at how far the pip is from the left hand side of the scope which
+   is the location of the radar transmitter. If the target goes further away, 
+   the pip will move to the right. If the target comes close to you, the pip will 
+   move left.
+
+   This pip has a finite rise time as the transmitter starts.
+   The width is set by the modulator stage in the transmitter.
+   Following the width, the pip has a finite fall time as the transmitter stops. This
+   creates a curved waveform; not just a line.
+
+   Here is some information on the pulse width for these old A Scope Marine Radars. There is
+   a switch that selects two pulse widths. Option 1 is Short Pulse (0.1 microsecond) for harbor
+   navigation and Option 2 is Long Pulse (1 microsecond) for open sea detection. We need
+   to implement this control. Perhaps a single keyboard key or single physical button.
+
+   Range and range lines on graticule
+
+   Please note that the graticules are plastic overlays over the screen. They need to be removed
+   and replaced when the operator changes the maximum range. This can be simulated with the graticule
+   being lifted toward the top of the scope as it is removed. Then the new graticule would be slid
+   down until it covers the scope. The graticule will be edge-lit with an incandescent lamp.
+
+   Here is a table of the available ranges and what markings will be on the plastic graticule.
+
+   1. 1.5 miles; markers every 0.25 miles
+   2. 3.0 miles; markers every 0.5 miles
+   3. 6.0 miles; markers every 1.0 miles
+   4. 12.0 miles; markers every 2.0 miles
+
+   There would be four available plastic overlays.
+
+   Range can be selected with two keyboard keys or two buttons on the panel, and is
+   indicated in the text status panel below the scope.
+
+   Please note that the range setting and the pulse width are separate controls.
+   There are two reasons.
+
+   1. Target discrimination and detection. Short pulse results in better range resolution while
+      a longer pulse width results in better detection of distant and weak targets.
+
+   2. Magnetron Duty Cycle. Too much time with long pulse width can put a strain
+      on the magnetron.
+
+2. PPI Scope - still being worked
+
+3. PAR Scope - still being worked
+