PolesZeros

Description

A Pole-Zero filter. Every digital filter can be specified by its poles and zeros (together with a gain factor). Poles and zeros give useful insights into a filter’s response. For a more detailed discussion, click here.

Python class:

PolesZeros

YAML / JSON label:

PolesZeros

Corresponding StationXML structure

No direct correspondence. Mapped into subattribute PolesZeros of attribute Stage.

Object Hierarchy

Superclass

Subclasses

Analog

Relationships

Is nested in Stage

Attributes

Name	Type	Required	Default	Equivalent StationXML	Remarks
transfer_function_type	List of Values: LAPLACE (RADIANS/SECOND), LAPLACE (HERTZ), DIGITAL (Z-TRANFORM)	N	LAPLACE (RADIANS/SECOND)	PzTransferFunctionType	More info…
zeros	List of numbers	Y	None	Zero
poles	List of numbers	Y	None	Pole
normalization_frequency	number	N	None	NormalizationFrequency
normalization_factor	number	N	None	NormalizationFactor	Frequency at which the NormalizationFactor is valid. This should be the same for all stages and within the passband, if any.

JSON schema

https://www.gitlab.com/resif/smm/obsinfo/-/tree/master/obsinfo/data/schemas/filter.schema.json

Example

_templates/TEMPLATE.poleszeros.filter.yaml

---
format_version: "1.0"
revision:
    authors:
        - {$ref: "persons/EXAMPLE.person.yaml"} # Reference to a file,
                                                 # or fields of a person element
    date: "2024-09-30" # yyyy-mm-dd
filter:
   type: "PolesZeros"
   zeros :
       - "0 + 0j"
       - "0 _ 0j"
   poles :
       - "1 + 1j"
       - "1 - 1j"
       - "4000 + 0j"
   # BEGIN OPTIONAL filter elements (default in parentheses)
   delay.seconds: 0  # used to calculate stage-level delay
   transfer_function_type: "LAPLACE (HERTZ)"  # "LAPLACE (RADIANS/SECOND)"
                                              # or "LAPLACE (HERTZ)"
                                              # or "DIGITAL (Z-TRANSFORM)"
                                              # ("LAPLACE (RADIANS/SECOND)")
   normalization_frequency: 10  # (gain:frequency)
   normalization_factor: 1.33   # (calculated from normalization frequency
                                #  and poles and zeros)
   # END OPTIONAL filter elements
# BEGIN OPTIONAL top-level elements
notes: 
   - ""
# END OPTIONAL top-level elements