Frequency Domain Processing
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The frequency domain processing components provide builders for operators that 
handle frequency-domain filtering, correction, and processing operations in 
VLBI fringe fitting.

:hops:`MHO_NotchesBuilder`
--------------------------

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Class                                           :hops:`MHO_NotchesBuilder`
Primary Functionality                           Builds a notches (frequency cut) operator
Key Features                                    | Constructs and adds MHO_Notches operator to toolbox
                                                | Implements frequency domain filtering/cutting
                                                | Returns bool indicating construction success
                                                | Removes specific frequency ranges from data
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The :hops:`MHO_NotchesBuilder` class builds a notches operator that performs frequency 
domain filtering by removing specific frequency ranges from the data. This is essential 
for eliminating radio frequency interference (RFI) and other unwanted signals that 
can contaminate VLBI observations.

The builder constructs the MHO_Notches operator and provides boolean feedback on 
the success of the construction process.

:hops:`MHO_PassbandBuilder`
---------------------------

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Class                                           :hops:`MHO_PassbandBuilder`
Primary Functionality                           Builds a passband (frequency chunk excision) operator
Key Features                                    | Constructs and initializes passband operator
                                                | Handles frequency domain filtering/excision
                                                | Returns bool indicating construction success/failure
                                                | Defines usable frequency ranges
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The :hops:`MHO_PassbandBuilder` class builds a passband operator that defines the 
usable frequency ranges for fringe fitting by excising frequency chunks that should 
not be used in the analysis. This is complementary to the notches operator and 
helps define the clean frequency ranges for processing.

The builder provides boolean feedback on the success or failure of the operator 
construction process.

:hops:`MHO_DCBlockBuilder`
--------------------------

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Class                                           :hops:`MHO_DCBlockBuilder`
Primary Functionality                           Builds a DC block operator
Key Features                                    | Constructs and adds MHO_DCBlock operator to toolbox
                                                | Inherits from MHO_OperatorBuilder
                                                | Implements DC blocking functionality
                                                | Removes DC component from frequency domain data
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The :hops:`MHO_DCBlockBuilder` class builds a DC block operator that removes the 
DC component from frequency domain data. This is important for eliminating DC 
offsets that can affect the quality of fringe fitting and correlation analysis.

The builder constructs the MHO_DCBlock operator and adds it to the processing 
toolbox for frequency domain DC removal.

:hops:`MHO_LSBOffsetBuilder`
----------------------------

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Class                                           :hops:`MHO_LSBOffsetBuilder`
Primary Functionality                           Builds a LSB (lower side band) offset operator
Key Features                                    | Constructs and initializes MHO_LSBOffset operator
                                                | ExtractStationIdentifier() method for station identification
                                                | Handles lower side band offset corrections
                                                | Compensates for frequency-dependent effects
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The :hops:`MHO_LSBOffsetBuilder` class builds a lower side band (LSB) offset operator 
that handles frequency-dependent corrections for the lower side band in heterodyne 
receiver systems. This correction is essential for maintaining proper frequency 
calibration in dual-sideband VLBI observations.

The builder includes station identification capabilities to ensure corrections are 
applied to the appropriate station's data streams.