Skip to main content
Version: 4.10

Sensors

Sensors

Sensors are used by Algorithms to quantify position, velocity, and attitude. Different Algorithms require different types of sensors. The available types are: Optical Attitude (e.g. Star Tracker), Position (e.g. GPS), Direction (e.g. Earth Sensor), Angular Velocity (e.g. Gyroscope), and Vector (e.g. Magnetic Field Sensor).

Any sensor can be associated to a set of Conditions. The sensor will only produce data if all of the Conditions are valid. If no Conditions are selected, the Sensor will always produce data.

Optical Attitude Sensor

These are used for Attitude Determination. To model an optical attitude sensor, the simulation requires the user to provide inputs on planar and roll accuracy. One Sigma Cross-Axis Error is the sensor’s cross-axis standard deviation for attitude, and the One Sigma Boresight-Axis Error is the radial error (standard deviation) around the center vector of the sensor.

Position Sensor

Position sensors provide a 3D-vector position estimate for the satellite; these are used for Orbit Determination. Input the standard deviation of distance error, assumed to be the same for each dimension.

Direction Sensor

Direction sensors provide information on the orientation of an external reference with respect to the satellite; these are used for Attitude Determination. Input a Reference Vector and the angle error (standard deviation) between the actual direction and measured.

Angular Velocity Sensor

Angular velocity sensors measure the angular rate of the spacecraft in the body frame; these are used for Attitude Determination. Input the standard deviation of the error.

Target Attitude Sensor

Target attitude sensors provide a quaternion estimate of a target's orientation with respect to the observer's body frame. These require a Space Target, a One Sigma Boresight-Axis Error, and a One Sigma Cross-Axis Error.

Target Position Sensor

Target position sensors provide a 3D-vector position estimate of a target's position with respect to the observer's body frame. These require a Space Target and a One Sigma Distance Error.

Target Range Sensor

Target range sensors provide a scalar magnitude estimate of the distance between an observer and a target. These require a Space Target and a One Sigma Distance Error.

Target Range Rate Sensor

Target range rate sensors provide a scalar estimate of the change in range between an observer and a target. These require a Space Target and a One Sigma Velocity Error.

Vector Sensor

Vector sensors provide information on the orientation and magnitude of an external reference vector with respect to the satellite; these are used for Attitude Determination. Input a Reference Vector for the vector sensor to measure, the standard deviation of the error and optional select an FoV to limit sense scope and direction. Adding an FoV is equivalent to associating a vector in FoV Condition.