Ashley Raiteri
Engineering leader. I write about scaling teams, deploying agentic AI in production, and lessons from building startups.
The Magic of the Kalman Filter: How I Learned to Stop Worrying and Love Sensor Fusion
There’s a moment in every engineer’s career when you stumble onto an algorithm so elegant it feels like cheating. For me, that moment came in a windowless lab in Tucson, Arizona, staring at three separate navigation systems that couldn’t agree on where a missile was. I was a guidance software engineer at Raytheon, working on the Tomahawk cruise missile. My job was sensor fusion — taking the outputs of GPS, an inertial measurement unit (accelerometers and gyroscopes), and DSMAC (Digital Scene Matching Area Correlator, which is a fancy way of saying “a camera that compares what it sees to stored photos of the ground”) and turning them into a single, confident answer to the question every guidance system needs answered at every moment: where am I, and where am I going? ...