WhizWheel by AstroGrad

Last crawled date: 3 years, 1 month ago

This WhizWheel is used to visualize a satellite in orbit based on the common orbital elements (COEs). The first five COEs (defined below) are assumed to be fixed for simple orbital motion. Once once you visualize those parameters, you've successfully simulated the orbit any given satellite is flying in. I printed this example at 120% the original size. I have created a plastic pin to hold the orbit onto the center of the orbital plane. A screw can also be used to attach the orbit as shown. The pin, or screw, represents the Earth at a focus of the orbit.
To visualize a satellite in orbit, you'll need the following COEs (a,e, i, RAAN, ArgP, v) to describe the size, shape, tilt, swivel, twist, and position of a satellite in an inertial coordinate frame. The size (a) and shape (e) of any orbit are defined by the semi-major axis and eccentricity respectively. These parameters define the orbit piece which is attached to the center of the whizWheel. A highly eccentric orbit is provided here to help with visualization.
The size or shape orbit can be modified if desired, but not recommended. The outer square of the WhizWheel represents the inertial coordinate frame on the plane of the elliptic. The first of the inner gimbals represents the location of the right ascension of the accenting node (RAAN). Simply swivel the n vector (pointing to the node) from I (the inertial axis on the outer frame) by the RAAN in degrees. The inclination, or tilt of an orbit, is represented by the next innermost gimbals. Simply tilt the orbital plane by your inclination (i) in degrees -- press down on the 270 degree simple for an accurate representation of the direction of tilt. The angle to perigee (the point of closest approach to the earth) is visualized by twisting the attached orbit so that the perigee points to the angle defined by the argument of perigee (ArgP). Once all of these COEs have been simulated on the WhizWheel you have successfully defined the simple orbital motion of a satellite around Earth. The final COE is the true anomaly (v), which defines the position of a satellite at a specific moment in time as measured from perigee. In simple orbital motion, this is the only COE which changes with time.
For a low Earth orbit a satellite may complete an orbit in roughly 90 minutes. But, out at geosynchronous orbit the satellite takes 24 hours to complete an orbit. The WhizWheel is a useful tool for visualizing any satellite in Earth orbit.