rf sensor model cleanup

@rfSensor/RSS.m

@@ -19,6 +19,5 @@ function value = RSS(obj, d, dx, dy, dz)
     cos_theta = (st .* (dx .* sa + dy .* ca) - ct .* dz) ./ max(d, eps);
     cos_theta = max(-1, min(1, cos_theta));
     theta = acosd(cos_theta);
-    gain  = 10 .* obj.beamwidthExponent .* log10((1 + cosd(theta)) ./ 2);
-    value = obj.P_TX_dBm + gain + obj.G_RX_dBi - obj.pathLoss(d);
+    value = obj.P_TX_dBm + obj.transmitterGain(theta) + obj.G_RX_dBi - obj.pathLoss(d);
 end

@rfSensor/halfAngle.m

@@ -5,12 +5,8 @@ function value = halfAngle(obj)
     arguments (Output)
         value (1, 1) double;
     end
-    % Sweep angular offset from boresight by evaluating transmitterGain at
-    % (obj.tilt + dtheta, obj.azimuth). The cosine difference identity guarantees
-    % the resulting angular offset from boresight equals dtheta exactly,
-    % independent of the actual pointing direction.
     dtheta = (0:0.1:179.9)';
-    gain = obj.transmitterGain(obj.tilt + dtheta, obj.azimuth * ones(size(dtheta)));
+    gain = obj.transmitterGain(dtheta);
     target = gain(1) - 3;
     idx = find(gain <= target, 1);
     if isempty(idx) || idx == 1

@rfSensor/initialize.m

@@ -1,7 +1,8 @@
-function obj = initialize(obj, txPower, bandwidth, centerFreq, rxGain_dBi, beamwidthExponent, tilt, azimuth, lossExponent)
+function obj = initialize(obj, txPower, temperature, bandwidth, centerFreq, rxGain_dBi, beamwidthExponent, tilt, azimuth, lossExponent)
     arguments (Input)
         obj (1, 1) {mustBeA(obj, "rfSensor")}
         txPower (1, 1) double;
+        temperature (1, 1) double;
         bandwidth (1, 1) double;
         centerFreq (1, 1) double;
         rxGain_dBi (1, 1) double;
@@ -16,6 +17,7 @@ function obj = initialize(obj, txPower, bandwidth, centerFreq, rxGain_dBi, beamw
 
     %% Provided values
     obj.P_TX = txPower; % Transmit power (W)
+    obj.T_0 = temperature; % Temperature (K)
     obj.BW = bandwidth; % Bandwidth (Hz)
     obj.f_c = centerFreq; % Center frequency (Hz)
     obj.G_RX_dBi = rxGain_dBi; % Receiving Antenna Gain (dBi)
@@ -29,4 +31,5 @@ function obj = initialize(obj, txPower, bandwidth, centerFreq, rxGain_dBi, beamw
     %% Computed values
     obj.P_TX_dBm = 10*log10(obj.P_TX/1e-3); % Transmit power in dBm
     obj.N = obj.k_B * obj.T_0 * obj.BW; % Thermal noise
+    obj.constantGainTerm_dB = 10 .* log10(2 * (obj.beamwidthExponent + 1)); % used in RSS calculation, only need to compute once
 end

@rfSensor/plotParameters.m

@@ -23,8 +23,11 @@ function f = plotParameters(obj)
         % For agent at altitude alt, ground target at tilt T has slant distance:
         D = alt ./ cosd(T);
 
-        % Compute RSS for each (d, t, a) triple
-        rss = obj.RSS(D(:), T(:), A(:));
+        % Convert LOS (D, T, A) to displacement vectors for RSS
+        dx = D .* sind(T) .* sind(A);
+        dy = D .* sind(T) .* cosd(A);
+        dz = -D .* cosd(T);   % negative: ground targets are below agent
+        rss = obj.RSS(D(:), dx(:), dy(:), dz(:));
         Fslice = reshape(rss, size(D));
 
         % Disc geometry: t=0 (nadir) -> center, t~90 (horizon) -> edge

@rfSensor/rfSensor.m

@@ -14,6 +14,7 @@ classdef rfSensor
         % Values computed at initialization
         P_TX_dBm = NaN; % Transmit power (dBm)
         N = NaN; % Thermal noise
+        constantGainTerm_dB = NaN; % used in RSS calculation, only need to compute once
         % Cached state (per timestep)
     end
     properties (Access = public)
@@ -23,7 +24,7 @@ classdef rfSensor
     end
 
     methods (Access = public)
-        [obj] = initialize(obj, txPower, bandwidth, centerFreq, rxGain, beamwidthExponent, tilt, azimuth); % initialize sensor, define parameters
+        [obj] = initialize(obj, txPower, temperature, bandwidth, centerFreq, rxGain, beamwidthExponent, tilt, azimuth); % initialize sensor, define parameters
         [SINR, SNR, obj, otherSensors] = sensorPerformance(obj, agentPos, targetPos, otherSensorsPos, otherSensors); % determine sensor performance for a given single sensor and target geometry
         [d, dx, dy, dz] = computePointToPoints(obj, agentPos, targetPos);
         [value] = halfAngle(obj); % tilt angle (deg) at which sensor performance is halved
@@ -34,7 +35,7 @@ classdef rfSensor
     end
     methods (Access = private)
         x = RSS(obj, d, dx, dy, dz); % Received signal strength (function of distance and tilt angle)
-        G_TX_dB = transmitterGain(obj, t, a); % Antenna gain for a given TX/RX pair 
+        G_TX_dB = transmitterGain(obj, theta); % Antenna gain for a given angle from boresight (degrees)
         L_FSPL_dB = pathLoss(obj, d); % Free space path loss for a given TX/RX pair
     end
 end

@rfSensor/transmitterGain.m

@@ -1,23 +1,12 @@
-function value = transmitterGain(obj, t, a)
+function value = transmitterGain(obj, theta)
     arguments (Input)
-        obj (1, 1) {mustBeA(obj, "rfSensor")};
-        t (:, 1) double; % LOS tilt angle
-        a (:, 1) double; % LOS azimuth angle
+        obj   (1, 1) {mustBeA(obj, "rfSensor")};
+        theta (:, 1) double; % angle from boresight (degrees)
     end
     arguments (Output)
         value (:, 1) double
     end
-    if ~isequal(size(t), size(a))
-        error("t and a must be the same size");
-    end
-
-    % Angular offset from boresight via spherical law of cosines
-    % Convention: t=0° nadir, t=90° horizon; a=0° +y, a=90° +x
-    cos_theta = sind(obj.tilt) .* sind(t) .* cosd(a - obj.azimuth) + ...
-                cosd(obj.tilt) .* cosd(t);
-    cos_theta = max(-1, min(1, cos_theta));  % clamp for numerical safety
-    theta = acosd(cos_theta);
-
-    % Cardioid family: peak at boresight (theta=0), null opposite (theta=180°)
-    value = 10 .* obj.beamwidthExponent .* log10((1 + cosd(theta)) ./ 2);
+    % Cosine pattern: peak at boresight, -inf dB at 90°.
+    % Clamped so targets behind the antenna (theta > 90°) get -inf rather than NaN.
+    value = obj.constantGainTerm_dB + 10 .* obj.beamwidthExponent .* log10(max(0, cosd(theta)));
 end