FAQ

1. What is TT&C? What is it for?
Telemetry, Tracking and Command is the communication module of FloripaSat, whose function is to make the communication between Ground Station and the satellite. It's very important too, because TT&C is responsible for receiving and processing commands from ground station.

2. What is the function of the beacon signal? What data is present?
The beacon is a sub-module and is responsible for periodically transmitting (every 10 seconds in energy level 1 or 2) some basic telemetry and the identification data (ID). The beacon will transmit all the time, except if the satellite is in hibernation or shutdown mode. The data is listed on this link and was added because it has fundamental informations.

3. Which frequencies are used by the TTC?
The frequencies used are:

• 145,9 Mhz to beacon;
• 437,9 Mhz to telemetry.

4. What is the minimum power needed to transmit from TTC?
The CubeSat will have the RF power output to the transmitting antenna input no greater than 1,5 W. But, it will have the RF power output to the transmitting antenna input no less than 1,0 W (or 30 dBm).

4. What is the transmission rate?
The TTC transmits data at a baud rate of 1200 bps.

5. What modulation/protocol is used?
This module shall modulate and demodulate information using GFSK. The TT&C beacon shall transmit packet in both NGHam and AX.25 protocols. It's important to have two protocols to compare the performance.

6. There is some kind of data verification when some transmission is received?
Yes.

7. What is the maximum range needed to receive the TTC signals?
The maximum range is about __km.

8. Into which parts the TT&C module is divided?
The TT&C board can be divided in six sub-parts:

• The microcontroller, which will be called “uC”;
• The radio transceiver, which will be called “radio”;
• The radio transmitter one, which will be called “Beacon 1”;
• The radio transmitter two, which will be called “Beacon 2”;
• The radio transmitter three, which will be called “Beacon 3”;