What is attitude control of a satellite?

The attitude & orbit control system (AOCS) controls the attitude and position of a complete space vehicle or satellite. Based on this function, the spacecraft orients its solar generators, thermal radiators, thrusters and particularly its payload units, optical instruments and antennas.

What is attitude and orbit control subsystem?

Altitude and Orbit Control (AOC) subsystem consists of rocket motors, which are capable of placing the satellite into the right orbit, whenever it is deviated from the respective orbit. AOC subsystem is helpful in order to make the antennas, which are of narrow beam type points towards earth.

What is TTC in satellite communication?

Telemetry, Tracking and Command (TTC) are vital functions of a spacecraft. They allow data to be communicated between the ground and the spacecraft for spacecraft control and command. The communication is through a telecommunication link established between the control station on the ground and the satellite.

Which are used for attitude control?

Attitude can be described using a variety of methods; however, the most common are Rotation matrices, Quaternions, and Euler angles.

How does a Magnetorquer work?

Magnetorquers are essentially sets of electromagnets laid out to yield a rotationally asymmetric (anisotropic) magnetic field over an extended area. That field is controlled by switching current flow through the coils on or off, usually under computerized feedback control.

What is TTC and M?

Advertisements. Telemetry, Tracking, Commanding and Monitoring (TTCM) subsystem is present in both satellite and earth station. In general, satellite gets data through sensors. So, Telemetry subsystem present in the satellite sends this data to earth station(s).

What is a transponder in satellite communication?

The term “satellite transponder” refers collectively to a transmitter-receiver subsystem on board the satellite that processes, amplifies and retransmits a range of frequencies (the transponder bandwidth) to another location/terminal/antenna on the earth.

What is an attitude sensor?

an instrument for determining the angular deviations of the axes of a spacecraft from preset directions. Attitude sensors are distinguished according to the principle of acquisition and processing of information.

What is attitude in navigation?

Attitude provides information about an object’s orientation with respect to the local level frame (horizontal plane) and true north. GNSS attitude solutions typically consist of three components: roll, pitch and yaw.

What is a magnetic torque rod?

A magnetorquer or magnetic torquer (also known as a torque rod) is a satellite system for attitude control, detumbling, and stabilization built from electromagnetic coils.

What is a transponder in satellite TV?

Digital television allows us to be more efficient and enables us to bundle a number of television services together into what is known as a multiplex. Each multiplex can then be broadcast from a satellite using an individual frequency.

What are secondary antennas?

A secondary antenna has a greater beam width than the primary antenna and receives the same tracking signal from the satellite.

How many transponders are on a satellite?

The Boeing 702 series of satellites, in contrast, can have more than 100 transponders, and with the use of digital compression technology each transponder can have up to 16 channels, providing more than 1,600 TV channels through one satellite.

What is attitude and Orbit Control in satellites?

The satellites’ “attitude,” or orientation and orbit control are controlled by a system consisting of sensors, actuators and software. The Attitude and Orbit Control System provides three-axis stabilized Earth-pointing attitude control during all mission modes and measures spacecraft rates and orbital position.

What is meant by attitude relative to satellite communication?

The term attitude relative to satellite communication corresponds to the orientation of satellite (vehicle) in space. Attitude control is defined as controlling the orientation of the axis of satellites that are orbiting in space.

Why do satellites have different attitudes in space?

The reason for this is that space is regarded as quite a gigantic place and nasty as well. So, even after fixing the satellite at a specific attitude number of forces, called disturbance torques hold the ability to change the attitude unnecessarily.

What is the attitude accuracy of an antenna?

When the beam is emitted towards the target it makes a cone and the angular size of the cone formed is regarded as attitude accuracy denoted by ψ. So, in such a case, the control system must properly operate so that the emitted beam must be focussed towards the receiving antenna.