  This paper presents a unique approach to the problem of calculating revisit
time metrics for different satellite orbits, sensor geometries, and
constellation configurations with application to early lifecycle design and
optimisation processes for Earth observation missions. The developed
semi-analytical approach uses an elliptical projected footprint geometry to
provide an accuracy similar to that of industry standard numerical orbit
simulation software but with an efficiency of published analytical methods.
Using the developed method, extensive plots of maximum revisit time are
presented for varying altitude, inclination, target latitudes, sensor
capabilities, and constellation configuration, providing valuable reference for
Earth observation system design.
