FIR
Description
A finite impulse response (FIR) filter is a filter whose impulse response (or response to any finite length input) is of finite duration, because it settles to zero in finite time.
The impulse response (that is, the output in response to a Kronecker delta input) of an Nth-order discrete-time FIR filter lasts exactly N + 1 samples (from first nonzero element through last nonzero element) before it then settles to zero. FIR filters can be discrete-time or continuous-time, and digital or analog.
Alternatively, FIR filters in obsinfo are also commonly documented using the Coefficients class, though FIR has the advantage of allowing representation of symmetric FIR coefficients without repeating them.
For a more detailed discussion, click here.
Python class:
FIR
YAML / JSON label:
FIR
Corresponding StationXML structure
FIR
Object Hierarchy
Superclass
Subclasses
None
Relationships
Is nested in Stage
Attributes
Name |
Type |
Required |
Default |
Equivalent StationXML |
Remarks |
symmetry |
|
Y |
None |
||
coefficients |
List of numbers |
N |
None |
||
coefficient_divisor |
number |
N |
1.0 |
NOT USED |
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 filter information file https://www.gitlab.com/resif/obsinfo/-/tree/master/obsinfo/_examples/Information_Files/instrumentation/dataloggers/responses/FIR/TexasInstruments_ADS1281_FIR1.filter.yaml
--
format_version: "0.107"
filter:
type: "FIR"
symmetry: "NONE"
delay.samples: 5
coefficient_divisor: 512
coefficients:
- 3
- 0
- -25
- 0
- 150
- 256
- 150
- 0
- -25
- 0
- 3