ra769_limits#

pycraf.protection.ra769_limits(mode='continuum', scale='dB', integ_time=<Quantity 2000. s>)[source]#

Limits for spectral line, continuum, and VLBI observations according to ITU-R Rec RA.769.

Parameters:

modestr, optional

Observing mode: ‘continuum’, ‘spectroscopy’, or ‘vlbi’ (default: ‘continuum’)

scalestr, optional

Default scale to use: ‘linear’, ‘dB’ (default: ‘linear’)

integ_timeQuantity, optional

Integration time [s] (default: 2000)

Note, if mode='vlbi' integration time is irrelevant, because the limits are based on 1% of the receiver noise plus antenna temperature.

Returns:

ra769_limitsTable

A table with the following columns:

“frequency” [MHz]
“bandwidth” [MHz]
“T_A” [K]
“T_rx” [K]
“T_rms” [K]
“P_rms_nu” [W/Hz, dB(W/Hz)]
“Plim” [W, dB(W)]
“Plim_nu” [W/Hz, dB(W/Hz)]
“Slim” [W/m^2, dB(W/m^2)]
“Slim_nu” [Jy, dB(W/m^2/Hz)]
“Efield” [uV/m, db(uV^2/m^2)]
“Efield_norm”, normalized to 1 MHz bandwidth [uV/m, db(uV^2/m^2)]

If mode='vlbi' the returned table has the following entries, only

“frequency” [MHz]
“bandwidth” [MHz]
“T_A” [K]
“T_rx” [K]
“Slim_nu” [Jy, dB(W/m^2/Hz)]

Notes

Because all columns are Astropy Quantities (see Quantity), one can easily convert between linear and log-scale at a later stage. the scale parameter just defines the scale to use initially.