For orbit calculation, see Earth Orientation Parameters (EOP). Polar motion is the movement of the rotation axis with respect to the crust of the Earth [1]. Components Polar motion consits of two major motions: Chandler wobble and annual wobble. Chandler wobble is the free motion with the period of about 435 days. Annual wobble is […]
Legendre Polynomials are the coefficients of the power series of the following generator function: [1] \[\frac{1}{\sqrt{1-2xz+z^2}} = \sum\limits_{n=0}^{\infty}P_l[x]z^n\] where \(P_l[x]\) is Legendre Polynomials at \(l\) th order. Taylor series is: \[\frac{1}{\sqrt{1-(2xz-z^2)}} = 1 + \frac{1}{2}(2xz-z^2) + \frac{1\cdot 3}{2\cdot 4}(2xz-z^2)^2 + \frac{1\cdot 3\cdot 5}{2\cdot 4\cdot 6}(2xz-z^2)^3 + \cdots\] after rearranging, \[=1 + xz + \frac{1}{2}(3x^2-1)z^2 +
What is Carrier-to-Noise Density Ratio (C/N0)? Carrier-to-noise density ratio (C/N0) is the ratio of carrier power to noise power density and denotes the strength of the power of carrier wave relative to the noise. C/N0 is often used in calculating link budget, and it describes the clarity of signal. Thus, the receiver should keep the
Magnetorquer is the actuator to control the attitude satellites by magnetic force generated from coil.
Momentum wheel is the actuator on satellites, which stabilize the attirude of satellites.
Reaction wheel is the actuator to control the attitude of satellites, which changes its number of revolutions to change attitude.
Bias momentum is one of the type of attitude control methods. bias momentum uses momentum wheel and effect of gyro stabilization.
Electrical Power Subsystem (EPS) manages the power of satellites. Satellites have solar panels to generate electricity, and battery to store the energy. EPS should design the circuit to control and distribute power.