Single Dish Calibration Techniques at Radio Wavelengths
  Calibrating telescope data is one of the most important issues an observer faces. In this chapter we describe a number of the methods which are commonly used to calibrate radio telescope data in the centimeter wavelength regime. This includes a discussion of the various methods often used in determining the temperature and gain of a telescope, as well as some of the more common difficulties which can be encountered. 
K. O'Neil