IMU Calibration Routine
Periodic In-Situ IMU Bias/Scale Calibration
The periodic in-situ IMU calibration routine is a navigation software process stored on radiation-hardened NOR flash that recalibrates inertial measurement unit bias and scale factors. Operating at 0.5 watts, it executes automated routines at 30-day intervals defined by Allan deviation thresholds. The routine derives bias corrections from static dwells paired with star tracker pose measurements, and computes scale factors through controlled rotational maneuvers. To maintain navigational performance across a 100-year mission lifetime where hardware aging degrades sensor accuracy, the software utilizes the lunar surface gravity of 1.62 m/s² as a stable, in-situ accelerometer scale reference.
Software routine periodically calibrating IMU bias/scale factors via star tracker pose, known-orientation maneuvers, and gravity reference.
Purpose
Software routine periodically calibrating IMU bias/scale factors via star tracker pose, known-orientation maneuvers, and gravity reference.
Context
Child of L2-NAV-IMU within the Lunar Ark system
Principles
- ▸Bias estimation from static dwell + star tracker
- ▸Scale-factor estimation from controlled rotation maneuvers
- ▸Lunar gravity (1.62 m/s^2) as accelerometer scale reference
- ▸Calibration interval driven by Allan deviation thresholds
- ▸Calibration history logged to L1-DVT
Typical implementations
- ▸Spacecraft IMU calibration heritage
- ▸Aerospace tactical-grade calibration procedures
- ▸ESA AOCS calibration philosophy
Lunar considerations
- ▸Long-mission calibration accommodates sensor aging
- ▸Automated maneuvers driven by L2-CDH-AUTO
- ▸ML-augmented calibration as data accumulates
Specifications
Functional
| primary function | Software routine periodically calibrating IMU bias/scale factors via star tracker pose, known-orientation maneuvers, and gravity reference. |
| calibration interval days | 30 |
Physical
| mass kg | 0 |
| materials | Code on rad-hard NOR flash |
| vacuum compatibility | True |
Operational
| power consumption w | 0.5 |
| thermal range c | -40, 70 |
| lifetime years | 100 |
| mtbf hours | 500000 |
Interfaces
Provides
- Updated calibration parameters
- Calibration history
Requires
- Reference pose during calibration
Cite this entry
Lunar Ark Codex. "IMU Calibration Routine" (L3-NAV-IMU-CAL). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-NAV-IMU-CAL
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.