Compensation¶

class lsst.ts.hexapod.Compensation(*, elevation_coeffs, temperature_coeffs, min_temperature, max_temperature)¶

Bases: object

Compute hexapod compensation for elevation, azimuth, and temperature.

The compensation is computed as offsets for x, y, z, u, v, w.

Parameters:

elevation_coeffs : list [list [float]]

Elevation CosinePolynomial coefficients, as a sequence of 6 coefficient sequences, for x, y, z, u, v, w. Each coefficient sequence must contain at least one element. Here is an example showing valid, though unrealistic, values:

elevation_coeffs=[
    [0.11, 0.012],
    [0.21],
    [0.31, 0.032, -0.0033],
    [0.000042, 0.000042],
    [0.000052, 0.000052],
    [0.000062],
]

temperature_coeffs : list [list [float]]

Temperature RangedPolynomial coefficients, with the same format as elevation_coeffs.

min_temperature : float

Minimum temperature for which temperature_coeffs is valid.

max_temperature : float

Maximum temperature for which temperature_coeffs is valid.

Raises:

ValueError: If elevation_coeffs, azimuth_coeffs or temperature_coeffs is not a sequence of 6 items, or if any item is not a sequence of floats with at least 1 element.

Methods Summary

get_offsets(elevation, azimuth, temperature) Get compensation offsets.

Methods Documentation

get_offsets(elevation, azimuth, temperature)¶

Get compensation offsets.

Parameters:	elevation : `float` Telescope elevation (deg). Must be in range [0, 90]. azimuth : `float` Telescope azimuth (deg). There are no range limits; azimuth is wrapped as needed. temperature : `float` Ambient temperature (C). There are no range limits; see `RangedPolynomial` for details.
Returns:	offsets : `list` [`float`] Offsets for x, y, z (um), u, v, w (deg), such that compensated value = nominal value + offsets.
Raises:	ValueError If elevation not in range [0, 90].

Navigation

Compensation¶