[cr] add printable enclosure designs

Author: jewbetcha

cad/printable-enclosure/launchmonitorbox.zip

@@ -36,6 +36,16 @@ class CFARConfig:
     # This masks out stationary clutter and slow movements
     dc_mask_bins: int = 150         # Mask bins 0-150 and 3946-4095 (~15 mph)
 
+    # Nyquist masking - bins to ignore near Nyquist frequency (max detectable speed)
+    # At 30ksps with 4096 FFT: bin 2047 = Nyquist-1 = ~208 mph
+    # Body reflection artifacts appear at this edge when standing in front of radar
+    nyquist_mask_bins: int = 10     # Mask bins 2038-2047 and 2048-2057
+
+    # Minimum magnitude threshold for detection
+    # Real golf signals have magnitude 1-100+, noise artifacts are 0.05-0.2
+    # This filters out low-energy edge artifacts that pass SNR threshold
+    min_magnitude: float = 0.5
+
     # Edge masking - don't detect near spectrogram edges
     edge_mask_time: int = 4         # Mask first/last N time windows
     edge_mask_freq: int = 50        # Mask first/last N frequency bins

src/openflight/streaming/cfar.py

@@ -108,16 +108,23 @@ def process_block(self, block: IQBlock) -> Optional[SpeedReading]:
 
         half = cfg.fft_size // 2
         dc_mask = cfg.cfar.dc_mask_bins
+        nyquist_mask = cfg.cfar.nyquist_mask_bins
 
-        # Analyze positive frequencies (outbound) above DC mask
-        pos_region = magnitude[dc_mask:half]
+        # Valid frequency ranges (excluding DC and Nyquist edges)
+        # Positive frequencies: dc_mask to (half - nyquist_mask)
+        # Negative frequencies: (half + nyquist_mask) to (fft_size - dc_mask)
+        pos_end = half - nyquist_mask
+        neg_start = half + nyquist_mask
+        neg_end = cfg.fft_size - dc_mask
+
+        # Analyze positive frequencies (outbound) - excludes DC and Nyquist
+        pos_region = magnitude[dc_mask:pos_end]
         pos_peak_idx = np.argmax(pos_region)
         pos_peak_bin = pos_peak_idx + dc_mask
         pos_peak_mag = magnitude[pos_peak_bin]
 
-        # Analyze negative frequencies (inbound) above DC mask
-        neg_start = half + dc_mask
-        neg_region = magnitude[neg_start:]
+        # Analyze negative frequencies (inbound) - excludes DC and Nyquist
+        neg_region = magnitude[neg_start:neg_end]
         neg_peak_idx = np.argmax(neg_region)
         neg_peak_bin = neg_peak_idx + neg_start
         neg_peak_mag = magnitude[neg_peak_bin]
@@ -153,6 +160,13 @@ def process_block(self, block: IQBlock) -> Optional[SpeedReading]:
         if snr < snr_threshold:
             return None  # Signal not strong enough
 
+        # Minimum magnitude filter (rejects low-energy edge artifacts)
+        min_mag = cfg.cfar.min_magnitude
+        if peak_mag < min_mag:
+            if self.debug:
+                print(f"   [LOW-MAG] mag={peak_mag:.4f} < {min_mag} speed={speed_mph:.1f}mph")
+            return None
+
         # Speed filter
         if not (cfg.min_speed_mph <= speed_mph <= cfg.max_speed_mph):
             if self.debug: