The previous level firmly established midline dynamics (neidan in Daoist yoga; awakening of kuṇḍalinī in Hindu yoga; completion stage practice of Tibetan Buddhism). This level expands the midline scope from inner (physical and nearby energy bodies) to outer (spacetime and higher dimensions). This corresponds to a yogi's gradual mastery of the mental plane (energy work can be effectively done simply by mental focus). Now, Vedic astrology focuses on Swarga loka proper (just the D27, Bhāṁśa and D30, Triṁśāṁśa, charts).

Nāda yōga — merging midline and near space with deeper space

Once a practitioner gains facility with coursing awareness into the space in the immediate vicinity of her or his physical body, the next step raises the ante. Here, the aim moves toward a higher (astral) energy body—one that provides access to lucid dreaming and full awareness during all phases of sleep. As this higher energy body switches online, the goal shifts up the ladder one more time—now, everyday awareness becomes the "sleep" that one sees through and gains mastery over.

The References page has some good suggestions for more advanced yogic practices and teachers that can help with this stage of the work. Tools especially helpful now include sound, mantra and phowa, which all can be used to churn the beginnings of an autonomous astral body.