ska_ost_senscalc.utilities
Module holding functions that handle celestial emission, atmospheric behaviour and Telescope Parameters
- class ska_ost_senscalc.utilities.Atmosphere[source]
Class to handle atmospheric properties
- static calculate_Tatm(weather, obs_freq)[source]
Calculate Atmospheric Temperature
- Parameters:
weather (float) – PWV in mm
obs_freq (astropy.units.Quantity) – observing frequency
- Returns:
Brightness temperature of atmosphere
- Return type:
astropy.units.Quantity
- class ska_ost_senscalc.utilities.Celestial[source]
Class to handle Celestial emission
- class ska_ost_senscalc.utilities.TelParams[source]
Class for handling Telescope Parameters
- static calculate_Trcv(obs_freq, obs_band, dish_type)[source]
Calculate Receiver Temperature. Works using obs freq only, not band. For SKA1 where bands overlap e.g. band 1, 2, returns the value reflecting the better performer.
- static calculate_Tspl(dish_type)[source]
Calculate spillover temperature. This is signal from the ground that gets onto the detector. In reality it could depend on the alt/az pointing of the dish - for now it is assumed to be 3K for SKA1 and 4K for MeerKAT.
- Parameters:
dish_type (DishType) – the type of dish
- Returns:
T spillover
- Return type:
astropy.units.Quantity
- static calculate_dish_efficiency(obs_freq, dish_type)[source]
Calculate aperture efficiency taking into account losses from feedhorn illumination of the aperture, phase errors at the dish surface, and diffraction.
- Parameters:
obs_freq (astropy.units.Quantity) – the observing frequency
dish_type (DishType) – the type of dish
- Returns:
dish aperture efficiency
- Return type:
astropy.units.Quantity
- static dish_area(dish_type)[source]
Calculate geometric area of a specified dish type.
- Parameters:
dish_type (DishType) – the type of dish
- Returns:
the dish area
- Return type:
astropy.units.Quantity
- static dish_fwhm(obs_freq, dish_type)[source]
Calculate the full-width at half-maximum (FWHM) of the dish at the observing frequency.
- Parameters:
obs_freq (astropy.units.Quantity) – the observing frequency
dish_type (DishType) – the type of dish
- Returns:
the fwhm
- Return type:
astropy.units.Quantity
- class ska_ost_senscalc.utilities.Telescope(value)[source]
Enumeration for the different telescope types
- class ska_ost_senscalc.utilities.Utilities[source]
Class to contain generally useful methods
- static Tx(freq, T)[source]
Function to apply correction to Rayleigh-Jeans temperature to describe the roll-off at high frequency of ‘Johnson noise’ in a resistor. Typically denoted by adding a subscript “x” to the temperature
- Parameters:
freq (astropy.units.Quantity) – the frequency
T (astropy.units.Quantity) – the temperature
- Returns:
the corrected temperature
- Return type:
astropy.units.Quantity
- static sensible_units(flux)[source]
Function to set fluxes to sensible units, where ‘sensible’ means that the numerical value lies between 0.1 and 100
- Parameters:
flux (astropy.units.Quantity) – the flux to be converted
- Returns:
the flux with value between 0.1 and 100 units
- Return type:
astropy.units.Quantity
- static to_astropy(quantity, unit)[source]
Convert input to astropy quantity with SKA standard unit
- Parameters:
quantity (scalar or astropy.units.Quantity) – the value to be converted
unit (astropy unit) – the standard unit to use
- Returns:
the quantity in SKA standard units
- Return type:
astropy.units.Quantity