https://ronanarraes.com/tags/julia/Recent content in Julia on Ronan Arraes Jardim Chagas, Ph.D.Hugoen-usMon, 10 Aug 2026 00:00:00 +0000https://ronanarraes.com/2026/08/satellitetoolbox-sgp4-performance/Mon, 10 Aug 2026 00:00:00 +0000https://ronanarraes.com/2026/08/satellitetoolbox-sgp4-performance/<p>The <a href="https://github.com/JuliaSpace/SatelliteToolbox.jl">SatelliteToolbox.jl</a> ecosystem is a set of packages for the Julia language that enables a wide range of analyses for space missions, from mission design studies to the day-to-day activities of an operational flight dynamics team.</p> <p>Among those activities, few are as demanding on a single algorithm as orbit propagation with SGP4/SDP4. The catalog of known space objects is distributed as mean elements — TLEs and, more recently, CCSDS orbit mean-elements messages (OMM) — and those elements only have meaning when propagated with the SGP4/SDP4 algorithm they were fitted for. Collision detection is the clearest example of why its performance matters: to screen a satellite for conjunctions, we must propagate its orbit against <strong>every object in the known space object database</strong> over the entire screening window, and repeat the whole process every time new element sets are published. At that scale, the cost of a single propagation call is multiplied by tens of millions, and the propagator&rsquo;s speed directly determines how often and how deeply an operations team can screen its fleet.</p>