Skip to main content
added 244 characters in body
Source Link
uhoh
  • 151k
  • 56
  • 505
  • 1.6k

This is a total coincidence, but I just ran across this introduction to the paper "New Synchronous Orbits Using the Geomagnetic Lorentz Force" New Synchronous Orbits Using the Geomagnetic Lorentz Force(1, 2) (Brett Streetman and Mason A. Peck: Journal of Guidance, Control, and dynamics, Vol. 30, No. 6, November–December 2007):

In a repeat-groundtrack orbit, the subsatellite point traces out a recurring pattern in some integer number of orbital periods. Traditionally, these orbits are achieved by adjusting the period of a satellite such that it completes an integer number of revolutions in exactly an integer number of sidereal Earth days.

So it seems that the term "repeat-groundtrack orbit" might be a suitably all-encompassing term for Earth orbits with rational number multiples of 1 sidereal day.

Here is a bit more of the first paragraph in case someone is interested...

Geostationary and geosynchronous Earth orbits (GEOs) are perhaps the most familiar and useful examples. These orbits have a mean motion equal to the spin rate of the Earth. We shall refer to orbits that repeat their groundtrack every orbital period as GT-1 orbits. Thus, all trajectories in GEO are in the GT-1 class. A more general class, the GT-x orbit, repeats its groundtrack every x revolutions. For example, satellites in the GPS constellation are in 12 sidereal hour orbits and can thus be considered GT-2 satellites. Many low-Earth-orbit (LEO) imaging satellites designed for full-Earth coverage also use repeat-track orbits. Every 16 days, over the course of 233 orbits, Landsat 7 covers the full Earth, making it a GT-233 satellite...

This is a total coincidence, but I just ran across this introduction to the paper New Synchronous Orbits Using the Geomagnetic Lorentz Force (Brett Streetman and Mason A. Peck: Journal of Guidance, Control, and dynamics, Vol. 30, No. 6, November–December 2007):

In a repeat-groundtrack orbit, the subsatellite point traces out a recurring pattern in some integer number of orbital periods. Traditionally, these orbits are achieved by adjusting the period of a satellite such that it completes an integer number of revolutions in exactly an integer number of sidereal Earth days.

So it seems that the term "repeat-groundtrack orbit" might be a suitably all-encompassing term for Earth orbits with rational number multiples of 1 sidereal day.

Here is a bit more of the first paragraph in case someone is interested...

Geostationary and geosynchronous Earth orbits (GEOs) are perhaps the most familiar and useful examples. These orbits have a mean motion equal to the spin rate of the Earth. We shall refer to orbits that repeat their groundtrack every orbital period as GT-1 orbits. Thus, all trajectories in GEO are in the GT-1 class. A more general class, the GT-x orbit, repeats its groundtrack every x revolutions. For example, satellites in the GPS constellation are in 12 sidereal hour orbits and can thus be considered GT-2 satellites. Many low-Earth-orbit (LEO) imaging satellites designed for full-Earth coverage also use repeat-track orbits. Every 16 days, over the course of 233 orbits, Landsat 7 covers the full Earth, making it a GT-233 satellite...

This is a total coincidence, but I just ran across this introduction to the paper "New Synchronous Orbits Using the Geomagnetic Lorentz Force" (1, 2) (Brett Streetman and Mason A. Peck: Journal of Guidance, Control, and dynamics, Vol. 30, No. 6, November–December 2007):

In a repeat-groundtrack orbit, the subsatellite point traces out a recurring pattern in some integer number of orbital periods. Traditionally, these orbits are achieved by adjusting the period of a satellite such that it completes an integer number of revolutions in exactly an integer number of sidereal Earth days.

So it seems that the term "repeat-groundtrack orbit" might be a suitably all-encompassing term for Earth orbits with rational number multiples of 1 sidereal day.

Here is a bit more of the first paragraph in case someone is interested...

Geostationary and geosynchronous Earth orbits (GEOs) are perhaps the most familiar and useful examples. These orbits have a mean motion equal to the spin rate of the Earth. We shall refer to orbits that repeat their groundtrack every orbital period as GT-1 orbits. Thus, all trajectories in GEO are in the GT-1 class. A more general class, the GT-x orbit, repeats its groundtrack every x revolutions. For example, satellites in the GPS constellation are in 12 sidereal hour orbits and can thus be considered GT-2 satellites. Many low-Earth-orbit (LEO) imaging satellites designed for full-Earth coverage also use repeat-track orbits. Every 16 days, over the course of 233 orbits, Landsat 7 covers the full Earth, making it a GT-233 satellite...

Source Link
uhoh
  • 151k
  • 56
  • 505
  • 1.6k

This is a total coincidence, but I just ran across this introduction to the paper New Synchronous Orbits Using the Geomagnetic Lorentz Force (Brett Streetman and Mason A. Peck: Journal of Guidance, Control, and dynamics, Vol. 30, No. 6, November–December 2007):

In a repeat-groundtrack orbit, the subsatellite point traces out a recurring pattern in some integer number of orbital periods. Traditionally, these orbits are achieved by adjusting the period of a satellite such that it completes an integer number of revolutions in exactly an integer number of sidereal Earth days.

So it seems that the term "repeat-groundtrack orbit" might be a suitably all-encompassing term for Earth orbits with rational number multiples of 1 sidereal day.

Here is a bit more of the first paragraph in case someone is interested...

Geostationary and geosynchronous Earth orbits (GEOs) are perhaps the most familiar and useful examples. These orbits have a mean motion equal to the spin rate of the Earth. We shall refer to orbits that repeat their groundtrack every orbital period as GT-1 orbits. Thus, all trajectories in GEO are in the GT-1 class. A more general class, the GT-x orbit, repeats its groundtrack every x revolutions. For example, satellites in the GPS constellation are in 12 sidereal hour orbits and can thus be considered GT-2 satellites. Many low-Earth-orbit (LEO) imaging satellites designed for full-Earth coverage also use repeat-track orbits. Every 16 days, over the course of 233 orbits, Landsat 7 covers the full Earth, making it a GT-233 satellite...