get_source_nefd

sofia_redux.scan.channels.channel_numba_functions.get_source_nefd(filtered_source_gains, weight, variance, flags, integration_time, integration_gain)

Return the source Noise-Equivalent-Flux-Density (NEFD).

The source NEFD is given as:

nefd = sqrt(n * t / sum(g^2 / v)) / abs(integration_gain)

where n are the number of mapping channels (unflagged and positive weights), t is the integration time, g is the source gain, and v is the channel variance.

Parameters:

filtered_source_gainsnumpy.ndarray (float)

The filtered source gains of shape (n_channels,) which is the product of channel coupling, gain, and source filtering.

weightnumpy.ndarray (float)

The channel weights of shape (n_channels,).

variancenumpy.ndarray (float)

The channel variances of shape (n_channels,).

flagsnumpy.ndarray (int)

The channel flags of shape (n_channels,) where non-zero values are not included in the calculation.

integration_timefloat

The integration time in arbitrary units (numba). Remember to reconvert after.

integration_gainfloat

The integration gain factor.

Returns:

nefdfloat

The source NEFD