If chopping was not used, then the most basic way of taking IR spectra is to observe the target along two slit positions. The sky is then removed by a process which is sometimes called double sky subtraction. The basic steps of how to reduce these type of data are:

- Dark subtraction
- Ghost removal *
- Non-linearity correction *
- Flat Fielding
- First sky subtraction
- Distortion Correction and wavelength calibration
- Registration and stacking
- Extraction
- Telluric line correction
- Flux calibration

For frames taken with chopping, the basic steps are:

- Ghost removal *
- Non-linearity correction *
- Flat Fielding
- A-B Subtraction
- Slit Curvature Correction and wavelength calibration
- Registration and stacking
- Extraction
- Telluric line correction
- Flux calibration

Steps that are marked with an asterisk have not been thoroughly tested.

- Dark subtraction
- Non-linearity correction
- Flat fielding
- First Sky subtraction - non chopping only
- A-B Subtraction - chopping only
- Slit curvature correction and wavelength calibration
- Combining 2d spectra - non chopping
- Combining 2d spectra - chopping
- Extraction
- Removing telluric lines
- Flux calibration