6.3.1 Bias and bias non-uniformity
The special bias non-uniformity calibration sequences were acquired six times during the 22 months covered by the DR2 data and nine times during the 34 months covered by DR3 data. Only one set of coefficients (the most frequently tested one that was obtained during commissioning) was used to correct the entire DR2 RVS dataset. Analysis of the nine sequences revealed a long-term trend in one of the coefficients. Therefore, the closest-in-time set of coefficients are used to correct the DR3 RVS dataset.