What does the concept of Arudha Pada mean in Jyotisha?
How is it calculated?
What are its practical applications?
The word आरूढ (Arudha) in Sanskrit means something that has risen.
It is derived from the root आरूह् which means ascending.
The concept of Arudha Pada in Jyotisha refers to the physical manifestation of a house i.e. the Arudha of a house represents the tangible manifestation of that house in the world of Maya.
Bhavas (houses) are considered inanimate in themselves e.g. the panchama bhava is associated with the abilities of a person. The Arudha of the 5th house, called A5 in short, refers to the tangible things used to judge one's ability.
Steps to find the Arudha of a house:
Find the sign of the house
Find where the Lord of that house is placed.
Count the distance of the Lord from its house.
If the distance is n, then the nth house from the Lord is the Arudha of the house.
Let us take an example. Say, we need to find A3 or Arudha of the third house.
Lets say that A3 has Libra sign
Say, the lord Venus is sitting in Capricorn
Hence, the lord is in the 4th house from its sign.
Hence, the 4th from the lord i.e the house containing Aries will be the Arudha of the third house. In this case, this is the 9th house.
If the Arudha turns out be the same house (for which Arudha was to be calculated) or 7th from it, that is considered invalid. In such a case, take the KarmaSthana (10th house) from the result calculated in Step 4.
For Aquarius and Scorpio, Rahu and Ketu are also taken as lords. Hence, if they are stronger, one view is to take them as the Lord to find Arudha. Although, there are disagreements to this view.
D-24 or ChaturVimsaAmsa is considered the Varga (division) associated with learning. Hence, 5th house in D24 would represent to ability to learn. A5 would refer to the tangible results of one's learning. This could be trophies, scholarships etc.
Shri PVR Rao says that some astrologers consider this as a part of Jaimini school of astrology. Although, he mentions that Maharishi Parashara talks about Arudha Pada in detail in Brihat Parashara Hora Shastra.
Excerpts from a video lecture by Shri PVR Rao: https://www.youtube.com/watch?v=nwoKpZj938s&index=8&list=PL8yOO2xYRcZt_P1ah4p2DJEOyEOVFJ3Bg