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

Filter

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/obsinfo/-/tree/master/obsinfo/data/schemas/filter.schema.json

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

Example

In the filter information file https://www.gitlab.com/resif/obsinfo/-/tree/master/obsinfo/_examples/Information_Files/instrumentation/sensors/responses/PolesZeros/Trillium_T240_SN400-_generic.filter.yaml .

---
format_version: "0.110"
revision:
   date: "2018-06-01"
   authors:
       - {$ref: "authors/Wayne_Crawford.author.yaml#author"}

filter:
   type: "PolesZeros"
   transfer_function_type: "LAPLACE (RADIANS/SECOND)"
   zeros :
       -     [0.0,  0.0]
       -     [0.0,  0.0]
       -   [-72.5,  0.0]
       -  [-159.3,  0.0]
       -  [-251,    0.0]
       - [-3270.0,  0.0]
   poles :
       -    [-0.017699,    0.017604]
       -    [-0.017699,   -0.017604]
       -   [-85.3,         0.0]
       -  [-155.4,       210.8]
       -  [-155.4,      -210.8]
       -  [-713,           0]
       - [-1140,          -0]
       - [-4300,          -0]
       - [-5800,          -0]
       - [-4300,        4400]
       - [-4300,       -4400]
   offset: 0

notes:
   - poles et zeros d'un Trillium T240 no de serie 400+
   - d'apres le fichier Trillium240_UserGuide_15672R7.pdf de Nanometrics.

extras: None