TIP (antenna tipping or ``skydip'') observations are done to measure the transmission of the Earth's athmosphere, by taking data at several points with the same azimuth but different elevations, spaced by equal steps in ``air mass''.
It is ESSENTIAL that the switching mode is TOTAL POWER during TIP.
This is in particular an important step in the calibration of observations with the bolometer.
The basic parameters of this observing mode and its options are: the azimuth, the range and step in airmass, and the time per subscan.