Why is there a central spike in frequency plots from many software defined radios?
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From Ted Cline 9/9/2025: The spike at frequency zero is just a consequence of the fact that your signal does not have an average of zero. The value at “frequency…
Comparing Software Defined Radios for Radio Astronomy
Here’s a compact, practical comparison of the popular low-to-mid cost SDRs you named (RTL-SDR v3/v4, ADALM-PLUTO, Ettus B210, LimeSDR family) plus a few other often-used SDRs (HackRF, Airspy, SDRplay) produced…
Meteorology-Relevant Facility at Harwell Campus
Here’s your image of Harwell Campus to set the scene: Meteorology-Relevant Facility at Harwell Campus RAL Space (Science and Technology Facilities Council) stands out as the key facility at Harwell…
Phased Arrays vs Aperture Synthesis
Great question! Phased arrays and aperture synthesis are closely related in radio astronomy and antenna engineering, but they’re not identical. Here’s a clear breakdown: Phased Arrays Aperture Synthesis Relationship ✅…
Normalising data produced by Easy Radio Astronomy Software Suite (ezRA) from multiple telescope systems to allow them to be combined to generate combined plots and maps.
This is very much a work in progress, so there isn’t a definitive answer from this post……. Andy Hi Ted, I asked ChatGPT to have a go at this and…
Formula for speed of light, and why it is a constant
What is the formula for the speed of light? Why is it considered a constant if there is a formula? Great question! Let’s unpack it step by step: 1. The…
Dipole vs radio dish or horn
If your “two cables joined in the middle, held aloft on poles with a single feed down the centre” is a centre-fed wire dipole / inverted-V style tuned to 1420…
British Astronomical Association Hydrogen Line Group (BAA H-Line Group) Meeting 1st September 2025
The video from this meeting is available here:
Normalising data files from multiple systems in ezRA
Ted Cline – N0RQV:secret ezCon command option …………. -ezConAntXTVTLevelL 1.3 -3.2 (multiply all AntXTVT sample values and add) Use per file (or batch files) to normnalise
How to take the signals from multiple antenna pairs and turn them into an actual sky image using Fourier transforms
Good question — you’re asking about the heart of radio interferometric imaging: how to take the signals from multiple antenna pairs and turn them into an actual sky image using…