Aerospace Fundamentals

Core Aerospace Toolbox functions for unit conversions, time conversions, coordinate transformations, and rotation representations.

When to Use

• Converting between aerospace unit systems (SI, imperial, nautical)
• Computing Julian dates, modified Julian dates, decimal years, or TDB time
• Transforming positions between ECEF, ECI, LLA, or flat Earth frames
• Converting between geodetic and geocentric latitude
• Building DCMs for frame transformations (ECI↔ECEF, ECEF↔NED, body↔wind, body↔stability)
• Converting between Euler angles, DCMs, quaternions, and Rodrigues vectors
• Using the quaternion object for rotation math, interpolation, or composition
• Identifying which coordinate frame data is expressed in

When NOT to Use

• Atmosphere models (atmosisa, atmoscoesa), use matlab-compute-aerospace-environment
• Airspeed corrections (correctairspeed), not covered here
• Orbit propagation or satellite maneuvers, use Aerospace Toolbox, Aerospace Blockset or Satellite Communications Toolbox
• Navigation-specific transforms (lla2enu, lla2ned), use Navigation Toolbox
• Simulink blocks, use /model-based-design-core:building-simulink-models with Aerospace Blockset

Workflow

1. Identify the coordinate frame, Determine what frame your data is in and what frame you need. See references/coordinate-systems.md for frame definitions and decision guide.
2. Convert units first, Ensure inputs match the function's expected units before calling transforms.
3. Apply the transformation, Use the appropriate function with correct argument ordering.
4. Verify, Round-trip the result back to the original frame; error should be < 1e-10.

Key Functions

Unit Conversions