To determine Right Ascension (RA) and Declination (DEC) from Keplerian elements, one must start with key parameters such as semimajor axis, inclination, eccentricity, longitude of the ascending node, longitude of periapsis, and mean longitude. These elements are used to calculate mean anomaly, eccentric anomaly, true anomaly, and radius. The conversion from these anomalies to RA and DEC involves applying specific mathematical transformations that relate the orbital parameters to celestial coordinates. Understanding the relationships between these elements is crucial for accurate celestial navigation and positioning. Ultimately, the process requires a solid grasp of both orbital mechanics and spherical astronomy.