Thinking Map of Kepler's Elements by Solomon Washington

Eccentricity

3076152 — 2020-09-28 13:25:32 UTC

(e)
describes the roundness
a - semi-major axis
b - semi-minor axis

e = 0 - circular orbit

e > 1 - not a complete orbit (non-closed orbit)

Orbit - a closed path around which a planet or satellite travels

3076152 — 2020-09-28 13:33:05 UTC

Keplerian Elements

3076152 — 2020-09-28 13:41:00 UTC

Two describe size and shape
Three describe orientation
One describes location within orbit
Plus time stamp

Semi-Major Axis

3076152 — 2020-09-28 14:02:32 UTC

(a)
describes the size of the ellipse
half of the largest diameter
from the center (most likely not central body)

Apogee - point of orbit farthest from Earth
Perigee - point of orbit closest to Earth
Altitude - distance from surface of Earth to either of these
in circles, apogee and perigee are the same and are undefined
Earth radius - 6378 km
Gravitational Constant = 6.67*10^-11 m^3/kg*s^2
Mass of Central Bodies - (M) = 5.98*10^24
Only orbital parameter that determines the orbital period (T) = calculated in seconds

Inclination

3076152 — 2020-09-28 14:44:01 UTC

(i)
Angle between Earths' equatorial plane and the plane of the orbit
height of inclination is the height of the ground trace

Ground Trace

3076152 — 2020-09-28 14:57:44 UTC

given ground trace, period and inclination can be found
top or bottom degree = inclination
the trace gap = way to determine orbit period
4 minutes per degree
gap degrees * 4 = period (T)

Right Ascension of the Ascending Node

3076152 — 2020-09-28 15:01:22 UTC

(RAAN, Ω)
the rotation or twist about the earth (yaw)
angle measure along equatorial point in space (Vernal equinox) and the point where the motion is from south to north across the equator (ascending node)
measured in degrees
Ascending - from south to north (up)
Omega = 0 when ascending node is aligned with vernal equinox

Argument of Perigee

3076152 — 2020-09-28 15:11:00 UTC

(funky w)
describes the orientation of the apogee and perigee
angle from the ascending node to the perigee point
measured in degrees (0 < w < 359)
only exists when perigee exists

True Anomaly

3076152 — 2020-09-28 15:16:02 UTC

(v, but it's a oopsulawn)
once orbit completely described, satellite's location on that orbit
measured in degrees
perigee = 0 degrees
apogee = 180 degrees

Epoch (time stamp)

3076152 — 2020-09-28 15:19:25 UTC

describes when the set of values was accurate for the satellite (snapshot)

3076152 — 2020-09-28 16:33:26 UTC

1st Law

3076152 — 2020-09-30 14:34:19 UTC

Satellites travel around Earth in an elliptical path. Earth at a foci

3rd Law

3076152 — 2020-09-30 14:34:53 UTC

The time it takes to complete an orbital period is related to it's semi-major axis

2nd

3076152 — 2020-09-30 14:37:27 UTC

A line drawn between Earth and a satellite will sweep out equal areas during equal time periods anywhere along the orbit
At the perigee a satellite is moving the fastest
At apogee a satellite is moving the slowest