RF Capture Validation

This project uses real-world RF data captured with a software-defined radio (SDR).
The RF capture chain was validated for stability prior to any dataset construction or ML modeling.

Hardware & Setup

• SDR: Nooelec NESDR SMArt v5 (RTL2832U + R820T)
• Host OS: macOS
• Sample Rate: 1.024 MS/s
• Gain Control: Manual (no AGC)
• IQ Format: Unsigned 8-bit interleaved I/Q

Validation Methodology

RF stability was verified by:

• Capturing long IQ recordings
• Computing power spectral density (PSD) from early and late time slices
• Comparing spectra to detect frequency drift or instability

A persistent PLL not locked warning was observed from the tuner, but its impact was evaluated empirically via spectral stability checks.

Results

• FM Broadcast (100 MHz)
  Wideband FM energy remained time-stable across capture windows.

  

• NOAA Weather Radio (162.5 MHz)
  Narrowband carrier remained sharply defined and fixed in frequency across time slices.

  

Conclusion

• PSD peaks align across time slices for both wideband and narrowband signals
• No observable frequency drift or spectral smearing
• PLL warnings confirmed non-impacting for spectral-feature-based ML tasks

The RF capture pipeline is therefore considered stable and suitable for downstream spectrogram generation and machine learning.