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1. The Competitors (Who has done this?)¶
These projects map directly to parts of your distributed array idea.
A. Project PANOPTES (For Transits/Black Holes)
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The Goal: Discover exoplanets via transit method (similar to your black hole reverberation mapping goal—both require monitoring brightness over time).
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The Hardware: They do not use telescopes. They use two Canon DSLRs with standard 85mm f/1.4 lenses inside a weather-proof box.
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Why it matters to you: They proved you don't need a "telescope" to do photometry. A fast camera lens (f/1.4) collects more light than a slow telescope (f/10), making it perfect for your Black Hole/Kilonova wide-field scans.
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Source: The PANOPTES Project: Discovering Exoplanets with Low-Cost Digital Cameras (arXiv:1406.6119).
B. Global Meteor Network (For SSA/Orbital Mechanics)
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The Goal: Track meteors to calculate their orbits and origin.
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The Hardware: They use Sony IMX291 security camera sensors (~$30 USD) connected to a Raspberry Pi.
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Why it matters to you: This is your SSA (Space Situational Awareness) solution. These cheap sensors are incredibly sensitive. If they can track a pebble burning up in the atmosphere, they can easily track a Starlink satellite or spent rocket body. They use "drift scanning" (no motors), which reduces the cost to ~$150 per station.
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Source: Global Meteor Network (Denis Vida et al.)
C. CRAYFIS (For Extreme Distributed Sensing)
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The Goal: Detect Ultra-High Energy Cosmic Rays.
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The Hardware: Smartphones lying face down with the camera covered.
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Why it matters to you: This proves the "massive N" concept. A single phone camera is tiny, but 100,000 phones form a detector the size of a city. You can use this "old phone" model for your array's notification system or for bright-event triangulation.
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Source: CRAYFIS: Cosmic RAys Found In Smartphones (arXiv:1410.2895).
1. Other Distributed "Low-End" Networks¶
Beyond the ones we discussed (Panoptes for planets, GMN for meteors), here are the other major players using cheap hardware for serious physics.
A. SatNOGS (Satellite Networked Open Ground Stations)¶
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The Goal: Track and decode telemetry from thousands of satellites (CubeSats, NOAA weather sats, ISS) that professional networks ignore.
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The Hardware: A $30 RTL-SDR (software-defined radio) dongle + a homemade antenna made of coat hangers or measuring tape + a Raspberry Pi.1
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Why it’s cool: It is the largest ground station network in the world. When a university launches a student satellite, they often rely on SatNOGS to tell them "is it alive?" because they can't afford a professional ground station.
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Your "In": You can build a receiving station for under $100 and automatically upload data to their global database.
B. CREDO (Cosmic-Ray Extremely Distributed Observatory)¶
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The Goal: Detect "Super-Preshowers"—massive cosmic ray cascades that span the size of a continent, potentially revealing Dark Matter interactions.2
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The Hardware: Your Smartphone.
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Relation to CRAYFIS: CREDO is the modern, active successor to the ideas pioneered by CRAYFIS. It runs as a background app, waking up when your phone is charging and dark to count particle hits.3
C. Radio SkyPipe / Radio Jove¶
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The Goal: Monitor solar storms and Jupiter's magnetic storms.
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The Hardware: A simple wire dipole antenna and a sound-card interface.
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Why it’s cool: While optical telescopes need clear skies, these radio networks run 24/7 through clouds and rain. They create a "seismograph" of the sun's magnetic activity.
2. The Story of CRAYFIS (and why it matters)¶
CRAYFIS stood for Cosmic RAys Found In Smartphones.4
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The Physics: When a high-energy particle (like a muon from a cosmic ray shower) hits a silicon camera sensor, it doesn't create a "picture" of an object. Instead, it deposits a tiny electric charge directly into a pixel, creating a bright white dot (a "hot pixel") on a black background.
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The Innovation: Before CRAYFIS (c. 2014), scientists thought you needed massive water tanks or lead plates to detect these. CRAYFIS proved that while a single phone camera is tiny, a million phones spread over a city creates a virtual detector surface area larger than the CERN Large Hadron Collider.
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The Status: The original CRAYFIS project is largely inactive/dormant, having served its purpose as a proof-of-concept. The baton has been passed to CREDO and DECO, which are active apps you can download today to do the exact same science.