From e19e9870d7f7d0bd5b49a86ffcbd8728c3468a7b Mon Sep 17 00:00:00 2001
From: Kevin D <krdee1@gmail.com>
Date: Sun, 26 Apr 2026 11:46:25 -0700
Subject: [PATCH] added SNR and SINR footprint images

---
 @rfSensor/pathLoss.m        |  4 ++--
 @rfSensor/plotPerformance.m | 29 ++++++++++++++++++-----------
 test/test_rfSensor.m        |  2 +-
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/@rfSensor/pathLoss.m b/@rfSensor/pathLoss.m
index 08198d0..c638699 100644
--- a/@rfSensor/pathLoss.m
+++ b/@rfSensor/pathLoss.m
@@ -7,7 +7,7 @@ function L_FSPL_dB = pathLoss(obj, d)
         L_FSPL_dB (:, 1) double
     end
 
-    % Free Space Path Loss (dB)
-    L_FSPL_dB = 20*log10(d) + 20*log10(obj.f_c) + 20*log10((4*pi)/obj.c);
+    % Free Space Path Loss (dB); d clamped away from zero (log undefined at d=0)
+    L_FSPL_dB = 20*log10(max(d, eps)) + 20*log10(obj.f_c) + 20*log10((4*pi)/obj.c);
 
 end
diff --git a/@rfSensor/plotPerformance.m b/@rfSensor/plotPerformance.m
index d5cc38c..f44b77b 100644
--- a/@rfSensor/plotPerformance.m
+++ b/@rfSensor/plotPerformance.m
@@ -9,6 +9,8 @@ function f = plotPerformance(obj, altitude, otherSensorsPos, otherSensors)
         f (1, 1) {mustBeA(f, "matlab.ui.Figure")};
     end
 
+    otherSensorsPos = otherSensorsPos + [0, 0, altitude];
+
     % Create grid on which to evalute SINR, SNR
     agentPos = [0, 0, altitude];
     d = max(10, max(vecnorm(otherSensorsPos(1:2), 2, 2)) * 1.25);
@@ -22,20 +24,25 @@ function f = plotPerformance(obj, altitude, otherSensorsPos, otherSensors)
     SINR = reshape(SINR, size(targetPosX));
     SNR = reshape(SNR, size(targetPosX));
 
-    % normalize
-    SINR = SINR ./ max(SINR);
-    SNR = SNR ./ max(SNR);
+    % normalize in linear scale
+    SINR = 10.^(SINR/10); SINR = SINR ./ max(SINR(:)); SINR = 10 * log10(SINR);
+    SNR  = 10.^(SNR/10);  SNR  = SNR  ./ max(SNR(:)); SNR = 10 * log10(SNR);
     
     f = figure;
-    imagesc(SNR);
-    axis("image");
-    colorbar;
-    title("Normalized SNR");
+    tiledlayout(1, 2, TileSpacing="compact", Padding="compact");
 
-    f = figure;
-    imagesc(SINR);
-    axis("image");
+    nexttile;
+    imagesc(distances, distances, SNR);
+    axis("image"); set(gca, 'YDir', 'normal');
     colorbar;
-    title("Normalized SINR");
+    xlabel("X (m)"); ylabel("Y (m)");
+    title("Linearly Normalized SNR (dB)");
+
+    nexttile;
+    imagesc(distances, distances, SINR);
+    axis("image"); set(gca, 'YDir', 'normal');
+    colorbar;
+    xlabel("X (m)"); ylabel("Y (m)");
+    title("Linearly Normalized SINR (dB)");
     
 end
\ No newline at end of file
diff --git a/test/test_rfSensor.m b/test/test_rfSensor.m
index 5f92eb3..ac2e76c 100644
--- a/test/test_rfSensor.m
+++ b/test/test_rfSensor.m
@@ -46,7 +46,7 @@ classdef test_rfSensor < matlab.unittest.TestCase
             tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi);
 
             altitude = 30;
-            otherSensorsPos = [5, 0, 400]; % relative to main sensor
+            otherSensorsPos = [6, -4, -1]; % relative to main sensor
             otherSensors = cell(1, 1);
             otherSensors{1} = tc.testClass; % 2 identical sensors