lod_unit

lod_unit#

Initialization for the λ/D unit and equivalency conversion module.

This module makes available the lod unit, representing the ratio of wavelength to diameter (λ/D), and lod_eq(), a function providing an equivalency for converting between λ/D and standard angular units. These tools are designed to facilitate calculations and conversions in optical systems and astronomical observations where λ/D is a commonly used metric.

The module is built on the Astropy units and equivalencies framework, ensuring compatibility with the Astropy ecosystem.

When imported, this module automatically extends astropy’s units system to make the λ/D unit available through the standard astropy.units interface.

Available Items:

  • lod A unit representing λ/D.

  • lod_eq() A function to convert between λ/D and angular units, given wavelength and diameter.

Submodules#

Attributes#

lod

An astropy unit representing the ratio of wavelength to diameter (λ/D).

Functions#

lod_eq(lam, D)

Convert between λ/D and angular units.

Package Contents#

lod_unit.lod = None#

An astropy unit representing the ratio of wavelength to diameter (λ/D).

lod_unit.lod_eq(lam, D)[source]#

Convert between λ/D and angular units.

Function to allow conversion between λ/D and angular units natively with the astropy units package.

Args:
lam (Astropy Quantity):

Wavelength

D (Astropy Quantity):

Diameter

Returns:

An astropy Equivalency object to allow conversion between λ/D and angular units.

Usage:
>>> diam = 10*u.m
>>> lam = 500*u.nm
>>> angseparation = 3 * lod
>>> angseparation.to(u.arcsec, lod_eq(lam, diam))
    <Quantity 0.03093972 arcsec>
Parameters:

  • lam (astropy.units.Quantity)

  • D (astropy.units.Quantity)

Return type:

astropy.units.Equivalency