nenupy.io.tf_utils.bandpass_correction_coefficients

nenupy.io.tf_utils.bandpass_correction_coefficients(frequency, lna_filter)[source]

Compute the coefficients to modify the shape of the bandpass response. The bandpass response (see get_bandpass()) has been computed for NenuFAR. It has been noted that the real subband shapes differ from the theoretical model. This deformation is chromatic and depends on the selected high-pass filter. As a study realized on April 2026, the subbands are assumed to be deformed as \({\rm slope} \times {\rm bandpass} + {\rm yintercept}\). Coefficients \({\rm slope} (\nu, {\rm filter})\) and \({\rm yintercept} (\nu, {\rm filter})\) were derived from real data.

Parameters:

frequency (Quantity) – Frequency at which the coefficients are computed. The lower the frequency, the higher the deformation.
lna_filter (int) – NenuFAR high-pass filter used during the observation. The higher the high-pass filter, the stronger the shape deformation.

Returns:

\({\rm slope}\) and \({\rm yintercept}\) for the selected frequency and lna_filter.

Return type:

[ndarray, ndarray]

Raises:

ValueError – If the selected filter is different than 0, 1, 2 or 3 (corresponding to a 10, 15, 20, 25 MHz high-pass filter).