Latitude optimized satellite constellation
A system can include a plurality of satellites synchronized in a Waves constellation tailored to maximize coverage of a target ground location at one or more predetermined latitudes with a minimal number of satellites. The plurality of satellites can orbit the Earth in a plurality of orbital planes evenly spaced in right ascension of ascending node. The plurality of satellites can be evenly spaced in true anomaly within each orbital plane. The Waves constellation can phase the plurality of orbital planes, such that satellites in neighboring orbital planes simultaneously cross the Equator together with synchronized true anomaly positions, all in ascending or descending motion, thereby forming a wave of satellites in all orbital planes that rise and fall together.
1 . A system comprising:
a plurality of satellites synchronized in a Waves constellation configured to separate northern, southern, or both satellite populations from equatorial satellite populations to provide non-equatorial coverage of a target ground location within a predetermined latitude band, wherein:
the plurality of satellites orbit a planetary body in a plurality of orbital planes evenly spaced in right ascension of ascending node,
the plurality of satellites are evenly spaced in true anomaly within each orbital plane,
the Waves constellation comprises a phasing of the plurality of orbital planes, such that satellites in neighboring orbital planes simultaneously cross an equator together with synchronized true anomaly positions, all in ascending or descending motion, thereby forming a wave of satellites in all orbital planes that rise and fall together, and
each satellite within the wave of satellites comprises neighboring satellites directly east and west at a same latitude due to the phasing such that the Waves constellation supports data links between the plurality of satellites within a single orbital plane, across orbital planes, or both among the wave.
2 . The system of claim 1 , wherein the plurality of orbital planes are evenly spaced in right ascension of ascending node so that as a first satellite in a first wave loses coverage of a target ground location at a predetermined latitude a second satellite in the first wave behind the first satellite in right ascension of ascending node resumes coverage of the target ground location.
3 . The system of claim 2 , wherein the first wave loses coverage of the target ground location as the first wave departs the predetermined latitude and a second wave resumes coverage of the target ground location at the predetermined latitude.
4 . The system of claim 1 , wherein the synchronized true anomaly positions allow satellites at a top and bottom of each orbit to fly in a coordinated manner over a maximum latitude and a minimum latitude, thereby providing maximum coverage of a target ground location at a predetermined latitude.
5 . The system of claim 1 , wherein an orbital overlap of satellites proportionally affects width of coverage of a target ground location at a predetermined latitude.
6 . The system of claim 1 , wherein the Waves constellation phases the plurality of orbital planes such that a predetermined latitude is covered by a number of satellites equal to the number of orbital planes.
7 . The system of claim 1 , wherein the Waves constellation phases the plurality of orbital planes so that a target ground location of a predetermined latitude remains in coverage for about 12% of an orbital period of a satellite.
8 . The system of claim 1 , wherein the plurality of satellites maximize a time for coverage of a target ground location at a predetermined latitude by orbiting in a same direction as a rotation of the planetary body.
9 . The system of claim 1 , wherein the Waves constellation consistently maintains at least one satellite in view of a predetermined latitude.
10 . The system of claim 1 , wherein the Waves constellation provides fractional coverage of 100% of latitudes between about 220 to about 50°.
11 . The system of claim 1 , wherein one or more additional Waves constellations, each at different inclinations, are stacked in layers to extend coverage of one or more predetermined latitudes.
12 . The system of claim 1 , wherein the data links are transmitted by a single antenna system with fixed pointing forward and aft.
13 . The system of claim 1 , wherein orbital parameters are tailored to adjust coverage of a target ground location at a predetermined latitude.
14 . The system of claim 13 , wherein the orbital parameters comprise a predetermined latitude, a predetermined altitude, and a predetermined inclination angle.
15 . The system of claim 1 , wherein the planetary body comprises the Earth.
16 . The system of claim 1 , wherein the data links comprise cross-link connections between a plurality of satellites that are co-planar across neighboring orbital planes when the co-planar satellites are at a minimum separation.
17 . The system of claim 1 , wherein the Waves constellation comprises an even number of a plurality of waves that are symmetric about the equator such that access behavior of the plurality of waves is mirrored at a Southern latitude band and a Northern latitude band.
18 . The system of claim 3 , wherein the first wave and the second wave are configured to be spaced in true anomaly at a transition time for the first wave to complete transit over the predetermined latitude band.
19 . The system of claim 8 , wherein each of the plurality of satellites are configured to fly with an eastward movement at a Northernmost part and a Southernmost part of a corresponding non-retrograde inclined orbit.
20 . The system of claim 19 , wherein an orbital path of each of the plurality of satellites is configured to align with a rotation of the planetary body when the corresponding satellite transitions between an ascending motion in a northern direction and a descending motion in a southern direction.