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OpTA: what I'm building

I’m in my last semester of grad school, and I wanted to build something for my thesis. So I’m building this:

OpTA (Optical Transit Array) is a low-cost, open-source system for tracking Earth orbital objects from the ground. The goal: design, build, and verify an autonomous optical array that produces satellite tracklets with accuracy suitable for initial orbit determination at a total hardware cost accessible to individual operators.

Meteor networks proved that distributed, community-run optical arrays work. Space Situational Awareness tracking hasn’t caught up. OpTA is meant to close that gap and democratize access to space tracking data for everyone.

Follow the build in my logbook

What it does

Each node is a fixed camera that stares at a patch of sky. As satellites transit, the pipeline detects them across frames, plate-solves against a star catalog, and outputs timestamped RA/Dec tracklets for orbit determination. Operation is fully autonomous: starts recording at dusk, runs until dawn, no human in the loop.

What I want to achieve

  • Tracklets with measured positional residuals against reference orbits
  • Dusk-to-dawn acquisition with zero manual steps
  • Total array hardware cost <$3,000 USD

Structure

A node is a single camera unit. An array is one or more nodes at a site sharing compute, GNSS timing, and power. A network is arrays at multiple sites contributing to a shared pool.

My thesis is scoped to be one validated node. A full array comes next if that holds up.

Where it stands

Currently working on the pre-study: proving the physics, sizing the hardware, defining interfaces. The key question right now is whether we can detect the targets we care about with hardware we can afford.

Thank’s to Prof. Benedikt Soja for supervising, and to the cohort, lecturers, study-coordinators and administration people at ETH Zürich for making this possible.

Prior art

A few projects shaped how I think about this:

  • Meteor networks: built for meteors, but proved that distributed, community-run optical arrays are viable at scale. The core concept carries over directly.
  • Project Luciole: the closest analogue to OpTA. Not open-source, but the architecture is similar. They operate at high latitudes, targeting sun-synchronous orbits where phase angles are favorable.
  • Slingshot Aerospace: assessed the feasibility of all-sky electro-optical tracking of mega-constellations in LEO, then built on it commercially with their Horus wide-field staring fence and Argus long-range telescope. A US commercial system, but strong evidence that the concept works and has a market.

#space-domain-awareness #satellite-tracking #orbit-determination #astrometry #optical-sensor #open-source #geodesy #computer-vision #hardware #thesis #ETHZurich