Skip to main content Skip to secondary navigation

Project: Angles-only Absolute and Relative Trajectory Measurement System (ARTMS)

Main content start

Angles-only navigation, in which observer spacecraft with onboard cameras obtain bearing angles to target space objects, is compelling for many distributed space systems. Cameras are accurate, low size-weight-power-cost sensors which may track cooperative and noncooperative targets with reduced reliance on external measurement sources. However, the lack of range information provided by measurements has limited the performance and autonomy of prior flight tests.

In response, the Space Rendezvous Laboratory (SLAB) has developed the angles-only Absolute and Relative Trajectory Measurement System (ARTMS). ARTMS applies innovative algorithms within a multi-agent framework to estimate the orbits of multiple observers and targets autonomously onboard in real-time. It provides autonomous, robust, scalable absolute and relative navigation using low-cost smallsat hardware with minimal reliance on maneuvers and ground interaction. ARTMS applies three core algorithms to 1) track multiple targets in camera images without prior relative orbit knowledge; 2) generate initial orbit estimates for the observer and its targets; and 3) refine system orbit and auxiliary state estimates by seamlessly fusing measurements from multiple observers shared over an inter-satellite link.

ARTMS is being flight-tested on board the NASA Starling mission, which launched in July 2023, and is conducting the first-ever demonstrations of angles-only navigation for a swarm of spacecraft in orbit. It has also been proposed as an enabler for space domain awareness objectives and future swarm and constellation missions in deep space.

Jointly, SLAB has developed the Optical Stimulator (OS), a variable magnification hardware-in-the-loop testbed for optical navigation. The OS consists of a camera under test, two lenses, and a microdisplay. A synthetic space scene is shown on the display, and component positions are adjusted and calibrated such that the images taken by the camera match what would be observed in orbit. Algorithms can therefore be verified under realistic image and noise characteristics.

Return to projects page

Related Publications

Kruger, J., D’Amico, S.;            
Observability Analysis and Optimization for Angles-Only Navigation of Distributed Space Systems;  
Advances in Space Research (2023).

Kruger, J., Koenig, A. W., D’Amico, S.;  
The Starling Formation-Flying Optical Experiment (StarFOX): System Design, Experiment Design and Pre-Flight Verification;  
Journal of Spacecraft and Rockets (2023).

Kruger, J., D'Amico, S., Roscoe, C., Westphal, J.; 
Angles-Only Tracking and Navigation for Approach and Rendezvous in Geosynchronous Orbits;  
33rd AAS/AIAA Space Flight Mechanics Meeting, Austin, TX, January 15-19, 2023.

Kruger, J., D'Amico, S.;
Observability Analysis and Optimization for Angles-Only Navigation of Distributed Space Systems;
11th International Workshop on Satellite Constellations & Formation Flying, Milano, Italy, June 7-10 (2022).

Iiyama, K., Kruger, J., D'Amico, S.;
Autonomous Distributed Angles-Only Navigation and Timekeeping in Lunar Orbit ;
ION International Technical Meeting, Long Beach, California, January 24-27 (2022).

Kruger, J., D'Amico, S.;
Autonomous Angles-Only Multitarget Tracking for Spacecraft Swarms;
Acta Astronautica, Volume 189, September 2021, pp. 514-529. DOI:

Sullivan, J., Koenig, A. W., Kruger, J., D'Amico, S.;
Generalized Angles-Only Navigation Architecture for Autonomous Distributed Space Systems;
Journal of Guidance, Control, and Dynamics, Vol. 44, No. 6 (2021), pp. 1087-1105. DOI: doi/abs/10.2514/1.G005439

Koenig A. W., Kruger J., Sullivan J., D'Amico S.;
ARTMS: Enabling Autonomous Distributed Angles-Only Orbit Estimation for Spacecraft Swarms;
2021 American Control Conference, New Orleans, Louisiana, May 26-28 (2021).

Kruger J., Wallace K., Koenig A. W., D'Amico S.;
Autonomous Angles-Only Navigation for Spacecraft Swarms around Planetary Bodies;
IEEE Aerospace Conference, Yellowstone Conference Center, Big Sky, Montana, March 6-13 (2021).

Koenig A. W., D'Amico S.;
Observability-Aware Numerical Algorithm for Angles-Only Initial Relative Orbit Determination;
2020 AAS/AIAA Astrodynamics Specialist Conference, South Lake Tahoe, California, August 9 - 13 (2020).

Sullivan J.;
Nonlinear Angles-Only Orbit Estimation for Autonomous Distributed Space Systems;
Stanford University, PhD Thesis (2020).

Beierle C., D'Amico S.;
Variable Magnification Optical Stimulator for Training and Validation of Spaceborne Vision-Based Navigation;
Journal of Spacecraft and Rockets (2019). DOI: 10.2514/1.A34337

Beierle C.;
High Fidelity Validation of Vision-Based Sensors and Algorithms for Spaceborne Navigation;
Stanford University, PhD Thesis (2019).

Sullivan J., Lovell A., D'Amico S.;
Angles-Only Navigation for Autonomous On-Orbit Space Situational Awareness Applications;
2018 AAS/AIAA Astrodynamics Specialist Conference, Snowbird, UT, August 19-23 (2018).

Sanchez H., McIntosh D., Cannon H., Pires C., Sullivan J., O'Connor B., D'Amico S.;
Starling1: Swarm Technology Demonstration;
32nd Annual Small Satellite Conference, AIAA/USU, SSC18-VII-08, Logan, UT, August 4-9 (2018).

Sullivan J., D’Amico S.;
Nonlinear Kalman Filtering for Improved Angles-Only Navigation Using Relative Orbital Elements;
Journal of Guidance, Control, and Dynamics, Vol. 40, No. 9, pp. 2183-2200 (September 2017).