LOCOOS Navigator

The LOCOOS Navigator regroups in a standalone package configurable and accurate attitude and orbit determination capabilities for satellite platform ranging from very small to large platforms.

The LOCOOS Navigator is a self-contained software module for three-axis stabilized spacecraft on low Earth orbit providing navigation information in its outputs:

  • estimates of the spacecraft position,
  • estimates of the spacecraft orientation,
  • time data,
  • Sun ephemeris,
  • Earth ephemeris.

The LOCOOS Navigator fuses optimally a large number of potential (User-chosen) sensor measurements:

  • Magnetometers,
  • temperature sensors,
  • solar-array current sensors,
  • light (Sun presence) sensors,
  • single-axis Sun sensors,
  • two-axis Sun sensors,
  • Earth horizon sensors,
  • star sensors,
  • inertia/reaction wheel tachometers,
  • attitude rate sensors,
  • accelerometers,
  • Global Positioning System (GPS),
  • NORAD Two-Line Elements (TLE).
LOCOOS Navigator Schematic

LOCOOS Navigator Schematic

The LOCOOS Navigator:

  • provides attitude and position estimates using any combination of the above sensors under condition of sufficient attitude and position observability. In addition to providing attitude and position estimates using any sensor combination, the LOCOOS Navigator has the particularity of being able to provide these estimates using only low-cost sensors. For example, for orbits with an inclination greater than 35 degrees, the LOCOOS Navigator can provide attitude and position estimation based only on magnetometer measurements.
  • is based on Unscented Kalman Filter technology. As such, it can propagate attitude or position during temporary sensor failure. It also adapts autonomously to the sensors available at any given time. It can cope with any individual sensor update rate.
  • has been designed in such a way to be easily customisable to any platform (nano-satellites as well as larger platforms), to various sensor interfaces and to implementation on various processing unit.
  • may be used as the primary mean for on-board position and attitude estimation or as a backup to another primary system in case of failure.