Chapter 9. Understanding the uncertainty table information in your data

Table of Contents

9.1. Uncertainty model
9.2. Flux calibration uncertainty budget

Last updated: 4 November, 2015

9.1. Uncertainty model

The HIFI flux calibration uncertainty is broken-down between the various components entering the general calibration equation (see Ossenkopf 2003, ALMA memo no. 442.1). For each component, the uncertainty is given as coefficients of a polynomial describing the possible dependency on the Intermediate Frequency (IF). In almost all cases, however, the uncertainty is flat over the IF and only the first coefficient is non-zero.

Uncertainties are LO-frequency dependent and given in percentages. Note that some uncertainties apply directly to the Level 2 or Level 2.5 products calibrated in Ta*, while some others will only apply to data converted into a certain intensity scale (see Chapter 18) - see the following section for more details.

Table containing the uncertainty model (values are in percentages) (for the V polarisation in this example)

Figure 9.1. Table containing the uncertainty model (values are in percentages) (for the V polarisation in this example)