Internet resources on hydrogen line radio astronomy
Here are some good internet resources — guides, tutorials, and reference material specifically useful for getting into hydrogen-line (21 cm, ~1420 MHz) radio astronomy:
📘 Amateur & Practical Guides
• “Hydrogen Line (1420 MHz) Observation” (LODARC) – beginner explanation of the 21 cm line and how it’s detected with SDR equipment. Hydrogen Line (general guide)
• Society of Amateur Radio Astronomers (SARA) – Hydrogen Line Radio Astronomy – collection of PDF resources (tutorials and introductory documents). Hydrogen Line Radio Astronomy (SARA)
• SKAO Table-Top Radio Telescope (TTRT) – a practical build kit and instructions for a simple hydrogen-line receiver using household materials. SKAO Table‑Top RT Project (build+software)
• PhysicsOpenLab: 21 cm Horn Antenna – detailed description of how to build a horn antenna tuned to the neutral-hydrogen line. Horn Antenna for 21 cm Line (PhysicsOpenLab)
📊 Reference & Data Tools
• All-Sky HI Profiles (EBHIS, GASS, LAB) – online interface to extract real neutral-hydrogen spectra from major surveys — excellent for comparison with your own measurements. All‑Sky HI Profile Generator
• LRO Category: Hydrogen-Line Radio Observation – blog posts with practical notes, antenna builds, and discussions about 1420 MHz observing. Radio Observation in Hydrogen Line (LRO)
• G4NNS Hydrogen Line Observing Group – example of a real amateur radio astronomy group doing backyard 1420 MHz observations. Hydrogen Line Observing Group (G4NNS)
📄 Technical & Background Reading
• HyperPhysics “Hydrogen 21-cm line” – succinct physics background on why the line exists and what it represents in neutral hydrogen. (Linked through recommended material on general radio-sky observing sites like the PICTOR PDF.)
• UCL Radio Telescope Phase1 (H-line detection context) – example of educational-level radio telescope projects that include hydrogen-line detection. UCL Radio Telescope (H‑line context)
📌 Extra (Helpful Communities)
These aren’t official teaching links but are great community discussions, practical tips, and shared setups — especially around SDR-based amateur hydrogen-line work:
- RTL-SDR.com talk on 21 cm amateur hydrogen-line projects (good context plus project links). RTL‑SDR 21 cm Talk
- Reddit r/radioastronomy threads — projects, mistakes, antenna ideas, debugging, real recordings, etc. (many posts include useful links and discussions).