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Brahe

Units

Units¶

Enumerations for specifying angle formats and time systems.

Angle Format¶

The AngleFormat enumeration specifies whether angles are in radians or degrees.

AngleFormat ¶

AngleFormat()

Python wrapper for AngleFormat enum

Initialize instance.

RADIANS `class-attribute` ¶

RADIANS: Any = AngleFormat.Radians

Python wrapper for AngleFormat enum

DEGREES `class-attribute` ¶

DEGREES: Any = AngleFormat.Degrees

Python wrapper for AngleFormat enum

Usage Example¶

import brahe as bh
import numpy as np

# Create rotation with angle in degrees
q = bh.Quaternion.from_euler_axis(
    axis=np.array([0.0, 0.0, 1.0]),
    angle=90.0,
    angle_format=bh.AngleFormat.DEGREES
)

# Create rotation with angle in radians
q2 = bh.Quaternion.from_euler_axis(
    axis=np.array([0.0, 0.0, 1.0]),
    angle=np.pi/2,
    angle_format=bh.AngleFormat.RADIANS
)

Time System¶

The TimeSystem enumeration specifies the time reference system for epochs.

TimeSystem ¶

TimeSystem()

Enumeration of supported time systems.

Time systems define different conventions for measuring and representing time. Each system has specific uses in astrodynamics and timekeeping applications.

Initialize instance.

UTC `class-attribute` ¶

UTC: Any = TimeSystem.UTC

Enumeration of supported time systems.

Time systems define different conventions for measuring and representing time. Each system has specific uses in astrodynamics and timekeeping applications.

TAI `class-attribute` ¶

TAI: Any = TimeSystem.TAI

Enumeration of supported time systems.

Time systems define different conventions for measuring and representing time. Each system has specific uses in astrodynamics and timekeeping applications.

TT `class-attribute` ¶

TT: Any = TimeSystem.TT

Enumeration of supported time systems.

Time systems define different conventions for measuring and representing time. Each system has specific uses in astrodynamics and timekeeping applications.

GPS `class-attribute` ¶

GPS: Any = TimeSystem.GPS

Enumeration of supported time systems.

Time systems define different conventions for measuring and representing time. Each system has specific uses in astrodynamics and timekeeping applications.

UT1 `class-attribute` ¶

UT1: Any = TimeSystem.UT1

Enumeration of supported time systems.

Time systems define different conventions for measuring and representing time. Each system has specific uses in astrodynamics and timekeeping applications.

Time System Descriptions¶

UTC (Coordinated Universal Time): Civil time standard used worldwide. Includes leap seconds to keep within 0.9 seconds of UT1.
TAI (International Atomic Time): Continuous time scale based on atomic clocks. Currently 37 seconds ahead of UTC (as of 2024).
TT (Terrestrial Time): Theoretical time scale for solar system calculations. TT = TAI + 32.184 seconds.
GPS (Global Positioning System): Continuous time starting from GPS epoch (January 6, 1980). Does not include leap seconds.
UT1 (Universal Time 1): Based on Earth's rotation. Computed from UTC using Earth Orientation Parameters (EOP).

Usage Example¶

import brahe as bh

# Create epoch in different time systems
utc_epoch = bh.Epoch.from_datetime(2024, 1, 1, 0, 0, 0.0, 0.0, bh.TimeSystem.UTC)
tai_epoch = bh.Epoch.from_datetime(2024, 1, 1, 0, 0, 0.0, 0.0, bh.TimeSystem.TAI)
gps_epoch = bh.Epoch.from_datetime(2024, 1, 1, 0, 0, 0.0, 0.0, bh.TimeSystem.GPS)

# Time system is preserved in the epoch
print(utc_epoch.time_system)  # Output: UTC
print(tai_epoch.time_system)  # Output: TAI