An analytical method to determine the minimum inclination and number of satellites needed to cover a specific latitudinal band continuously using a specific sensor FOV.
The Walker notation is the mathematical baseline for distributing satellites uniformly across multiple planes to optimize global coverage. Notated as = Total number of satellites in the constellation. = Number of equally spaced orbital planes.
Coverage is often considered the driving requirement. The entire constellation's size, cost, and complexity are dictated by the needed frequency and duration of access to specific ground points. An analytical method to determine the minimum inclination
Digital versions of Wertz's book and related worksheets can sometimes be found on academic hosting sites like (43MB file). Supporting Guides:
Higher radiation exposure (Van Allen belts), higher launch cost than LEO Broadcast TV, weather monitoring, missile warning = Number of equally spaced orbital planes
Highly stable orbits ideal for Positioning, Navigation, and Timing (PNT) architectures like GPS, GLONASS, and Galileo. They strike a balance between coverage footprint and signal attenuation. Geostationary and Geosynchronous Orbits (GEO/GSO) Altitude: Exactly 35,786 km.
Use tradespace exploration software to balance cost (number of launches) against performance (revisit frequency). 4. Constellation Management and Operations Digital versions of Wertz's book and related worksheets
A specific type of LEO where the satellite passes over any given point of the Earth's surface at the same local solar time. This is the best choice for missions requiring consistent lighting.
Do not experience atmospheric drag. At end-of-life, they use remaining propellant to boost themselves into a "Graveyard Orbit" located approximately 300 km above the active GEO belt to clear the operational lane for future missions. Finding Advanced Design Resources and PDFs
Think of it as the advanced sequel to two other foundational texts in the field: Spacecraft Attitude Determination and Control (SADC) and Space Mission Analysis and Design (SMAD). While those books provide the essential introduction to mission engineering, OCDM provides the much deeper detail, particularly on the key topic of . Where SADC and SMAD get you started, OCDM is the resource you turn to for the complex, real-world engineering challenges of requirements definition, mission geometry, orbit and constellation design, relative motion of satellites, observation and measurement systems engineering, and orbit control and management.