Since Rahu and Ketu are shadow planets they are studied based on the planets that are aspecting them or conjunct with them.
However, Professor Krishnamurthy went one step further than his friends. They explored using stellar astrology methods to interpret the birth chart. The initial idea was conceived by his friends the Late R. KP astrology is the brainchild of Late Professor Kuthur Subbaiyer Krishnamurthy (1908- 1972). This amalgamation of methods also adds its own unique rules, steps and methods to analyse a birth chart. It also uses certain methods that are used in Western astrology. It is a more detailed system that is built on the foundation of Vedic astrology. Though the basic definitions of Rashis, planets and the Zodiac are the same, the methods and rules of interpretation in KP astrology differ.
However, there are many different systems and schools of astrology that also give excellent results. The most widely practised system of Vedic astrology is the Parashari method.