21‑cm Hydrogen Line with RTL‑SDR 🔭🌌

An amateur radio astronomy experiment to detect the galactic 21‑cm HI line (1420.4058 MHz). Data recorded with SDRangel (Radio Astronomy Plugin) and analyzed in a small Jupyter notebook. ✨

Hardware ⚙️

• RTL‑SDR dongle
• Nooelec SAWbird+ H1
• 3D printed 8‑turn helix antenna with 30×30 cm reflector

Software 💻

• SDRangel + Radio Astronomy Plugin
• Data analysis in a jupyter notebook with numpy, matplotlib, astroquery

Data Recording 📡

• Center frequency: 1420.400 MHz
• Sample rate / bandwidth: 2.0 MS/s, 2.0 MHz
• FFT size: 2048
• Integration per spectrum: ~10 minutes