Low Cost Satellite Constellation Design Using Walker's Method for a Specified Launch Station

Satellite constellation is IRNSS, consists of 7 satellites which provides regional coverage only. The objective of this work is to design a satellite constellation for worldwide coverage, from a specified launch station and schedule the launch date and time of the satellites. Satellite constellations were developed using the Walker's method, by varying the height, inclination, orbital plane, phasing parameter using the System Tool Kit (STK) software and select the suitable one based on the parameter Geometric Dilution of Precision (GDOP). The value of GDOP should be minimum for better constellation. Satellite constellation design at a height of 23000 km, gives an arrangement of 30 satellites in 10 orbital plane, with phasing parameter 6 and inclination of 45 degree. In Walker's method, satellites are arranged uniformly at an equal altitude and inclination. Compared to polar constellation method coverage using Walker constellation method is more in the equatorial plane, also the number of satellites required per plane is low. The proposed satellite constellation gives GDOP value 2.8, hence satellite constellation is better.