Processing GPI Data, Step by Step

Let’s consider in turn each major topic that must be addressed during the processing of GPI data.

Note

Our goal here is not to document pipeline software (though that will be discussed) but rather to document our understanding of the properties and performance of the instrument itself, in terms of their effects on data processing. This document is not intended as a complete guide to achieving science-grade calibrations of your GPI science data! Not yet anyway. For now this is just a first draft discussion of what the different calibration files are, why they are required, and how you might go about generating them.

In many cases, the Data Parser will automatically generate a good set of recipes for reducing some/all of your calibration files.

This page takes the alternate approach, of describing what you need to know in order to perform the process yourself, understand how it all works, etc.

Caution

This documentation is still incomplete and a work in progress!

• Darks
• Thermal/Sky Backgrounds
• Bad Pixels
• Destriping and Microphonics
• Saturation and Nonlinearity
• Persistence
• Flat Fielding
• Flat Fielding: Lenslet Array Flat
• Wavelength Calibration
• Datacube Extraction
• Satellite Spot Calibrations
• Astrometric Calibration and Distortion Correction
• Photometric Calibration
• PSF Subtractions
• Spectral Extraction of Companions

If you’re interested in GPI polarimetry, then you should also consult

• Polarimetric Spot Location Calibration
• Instrument Polarization
• Polarization Sequence Combination