SatelliteCameraViewer.ISSAttitude module

ISSAttitude - ISS International Space Station functions

class SatelliteCameraViewer.ISSAttitude.ISSAttitude[source]

Bases: object

ISSAttitude - ISS International Space Station functions

Methods

apply_tea_to_quaternion(q, tea_deg)

Apply TEA yaw/pitch/roll offsets to a base attitude quaternion.

docking_port_vector_eci(port_name, ...)

Body-frame unit vectors for ISS docking ports.

iss_in_eclipse(r_eci)

Returns True if ISS is in Earth's umbra (full shadow).

lvlh_frame(r_eci, v_eci)

propagate_from_tle(tle_line1, tle_line2)

solar_beta_angle(r_eci, v_eci)

In orbital mechanics, the beta angle (β) is the angle between a satellite's orbital plane around Earth and the geocentric position of the Sun.

tea_offsets_deg([port_config])

TEA values from NASA ISS Motion Control System documentation: Current +XVV TEA: yaw=-4 deg, roll=0.9 deg Pitch varies from -12 to -2 deg depending on visiting vehicles.

xvv_attitude_quaternion(r_eci, v_eci)

Construct quaternion for XVV attitude:

classmethod apply_tea_to_quaternion(q, tea_deg)[source]

Apply TEA yaw/pitch/roll offsets to a base attitude quaternion.

classmethod docking_port_vector_eci(port_name, quaternion_xyzw)[source]

Body-frame unit vectors for ISS docking ports. Based on ISS body axes defined in ESA reference frames.

Parameters:

port_name – ISS port name

classmethod iss_in_eclipse(r_eci)[source]

Returns True if ISS is in Earth’s umbra (full shadow).

Parameters:

r_eci – ISS position vector (km)

classmethod lvlh_frame(r_eci, v_eci)[source]
Parameters:
  • r_eci (float) – ECI position.

  • v_eci (float) – ECI velocity.

Returns:

Returns LVLH frame unit vectors from ECI position and velocity. Based on ESA ISS Reference Frames: Z_LVLH = -r_hat (nadir or -zenith) Y_LVLH = -h_hat (opposite orbit normal) X_LVLH = Y × Z (velocity direction)

Return type:

dict

classmethod propagate_from_tle(tle_line1: str, tle_line2: str)[source]
Parameters:
  • tle_line1 (str) – TLE line one.

  • tle_line2 (str) – TLE line one.

Returns:

A tuple (r_eci_km in Km, v_eci_km_s in Km/s) from a two-line TLE.

Return type:

(float, float)

classmethod solar_beta_angle(r_eci, v_eci)[source]

In orbital mechanics, the beta angle (β) is the angle between a satellite’s orbital plane around Earth and the geocentric position of the Sun. The beta angle determines the percentage of time that a satellite in low Earth orbit (LEO) spends in direct sunlight, absorbing solar radiation

Yearly Variation: The ISS beta angle fluctuates between roughly -75 and +75 degrees over a 60-day precession period and on an annual cycle.

classmethod tea_offsets_deg(port_config='DEFAULT')[source]

TEA values from NASA ISS Motion Control System documentation: Current +XVV TEA: yaw=-4 deg, roll=0.9 deg Pitch varies from -12 to -2 deg depending on visiting vehicles.

classmethod xvv_attitude_quaternion(r_eci, v_eci)[source]
Construct quaternion for XVV attitude:

+X = velocity direction +Z = nadir +Y = completes RH frame