SensitivityAnalyzer

SensitivityAnalyzer.

Analyzer for telescope sensitivity.

DocLib 792 describes this analyzer and the associated theremin graph.

Metrics

dias_data_<task name>_average_sensitivity

RMS of thermal noise, averaged over inter-cylinder baselines, all frequencies, and 1.5 hours.

Labels
pol : Polarization of the feeds averaged (EW/NS).

Output Data

h5 file, containing noise rms (Jy), averaged over all feeds for each polarization, as a function of frequency and time. The input file is the chime stacked dataset.

File naming

<TIME>_<output_suffix>.h5 TIME is a unix timestamp of the first time record in each file and output_suffix is the value of the config variable with the same name. Output file is created for each input file read.

Indexes

freq
Frequency indexes.
pol
Two polarizations for the feeds, index 0 is E-W polarization and index 1 is N-S polarization.
time
Unix time at which data is recorded.

Datasets

rms
Noise rms, computed from the fast cadence data, as a function of frequency and time.
count
Normalization to the summed and weighted noise variance.

Attributes for output dataset

instrument_name
Correlator for the acquired (chime).
collection_server
Machine at which the script is run.
system_user
User account running the script.
git_version_tag
Version of code used.

Config Variables

dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.correlator

Source of the input data

Type:str
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.output_suffix

Suffix for the output file

Type:str
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.acq_suffix

Type of dataset to be read

Type:str
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.nfreq_per_block

number of frequency channels to be run in one block loading all frequency channels at the same time leads to memory error

Type:int
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.include_auto

option to include autocorrelation

Type:bool
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.include_intracyl

option in include intracylinder baselines

Type:bool
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.include_crosspol

option to include crosspol data

Type:bool
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.sep_cyl

option to preserve cylinder pairs

Type:bool
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.cyl_start_char

Starting character for the cylinders (ASCII)

Type:int
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.cyl_start_num

Offset for CHIME cylinders (due to inital numbers allotted to pathfinder)

Type:int
dias.analyzers.sensitivity_analyzer.SensitivityAnalyzer.lag

Number of hours before time of script execution for searching the files

Type:timedelta

Additionally, the config parameters of the base class are expected in the task file

dias.analyzer.Analyzer(name, write_dir, …) Base class for all dias analyzers.