FITS Assembler

L0 FITS Format

As per Data Format, the post-observation 'Level 0' (L0) format expected by the DRP is:

There is one L0 FITS per observation.
It contains all the raw data from the observation.

Background Infrastructure

Proposed directory structure for KPF:

kpf-asl-prime → KPF FITS Main Directory → L0 FITS Directory

→ Sub-FITS Directory → Green

→ Red

→ Ca_HK

→ ExpMeter

→ Guidecam

→ Solar_Irrad

The sub-FITS directories will hold the separate FITS from each subsystem before L0 assembly

Final L0 Filename

As per KPF File Names, the L0 Filename expected by DRP is:

Notes on obsID

The KPF “Observation ID” (obsID) will be stored in a keyword. It will be an integer that is incremented at the start of each new KPF observation/exposure.

Each subsystem will take this obsID and:

• place it within the head of each sub-FITS

• use it within the sub-FITS filenames (“prefix_obsID.FITS”)

This allows for straightforward assembly of the sub-FITS into L0 FITS (assembler only needs to look at filenames).

However, placing the obsID into the headers as well maintains obsID traceability after the L0 is created and the sub-FITS filenames are lost.

sub-FITS

•We’d like each separate HDU and sub-FITS to be stand-alone, and have all of the relevant information within. 

At end of exposure

get current obsID from keyword

Go into each sub-dir and look for FITS with this number within

Filenames

Suggested filenames for the sub-fits are: