CATARINA – A1 communicates through VHF and UHF bands
CATARINA – A1
The Catarina Constellation encompasses a set of satellites with the goal to provide services, mainly, to the civil defence, contributing to the country’s sustainable socioeconomic development agenda. Some of the Catarina Constellation satellites will provide a global coverage amateur radio service. The provided service is a digital store-and-forward repeater where digital frames will be stored and relayed by the satellite. All people involved in the service operation will be required to have an amateur radio license. The constellation has institutional support from the Brazilian Space Agency.
The beacon is sent periodically and it provides the satellite basic statistics and data.
The downlink provides complete satellite packets. The uplink allows telecommands to be received.
Open to the ham radio community, there are three open commands: ping, data request and message broadcast.
CATARINA – A1 uses two different protocols: NGHam and SBCD. Both for VHF and only NGHam for UHF.
Using the CATARINA – A1 custom-made software, it is possible to process and decode the collected data.
NORAR ID:
International Designator:
Altitude: 550km;
Inclination: 97.9°;
Cycle Repetition: 31 days;
Orbit Period: 5878.8 seconds;
Ascending Node Local Time: 10:30 a.m.
Parameter | Value |
---|---|
Frequency | 468 MHz |
Modulation | GMSK |
Protocol | NGHam |
Deviation | 10 kHz |
Baudrate | 4800 bps |
Output Power | 30 dBm (1 W) |
Field | Offset | Length [bytes] | Content |
---|---|---|---|
Flags | 0 | 2 | Variable |
OBDH Status | 2 | 6 | Variable |
IMU Accelerometer | 8 | 12 | Variable |
IMU Gyroscope | 20 | 12 | Variable |
OBDH Misc. | 32 | 6 | Variable |
OBDH Uptime | 38 | 4 | Variable |
Solar Panel Sensors | 42 | 12 | Variable |
Main Radio | 54 | 19 | Variable |
Solar Panels Data | 73 | 18 | Variable |
EPS Misc. | 91 | 8 | Variable |
Battery Monitor | 99 | 21 | Variable |
Temperatures | 120 | 21 | Variable |
Energy Level | 141 | 1 | Variable |
RUSH Data | 142 | 40 | Variable |
Payload X | 182 | 7 | Variable |
There are three types of uplink packets: Data request, ping and message broadcast. Each one is described in the table below:
Command | Length [bytes] | Content |
---|---|---|
Data request | 8 | “dr” + flags |
Ping | 8 | “pg” + requester callsign |
Message broadcast | Up to 28 | “br” + requester callsign + message |
Module | Duty Cycle (100%) | Power (mW) |
---|---|---|
OBDH | 100 | 115 |
TTC (radio 1 RX) | 95 | 65 |
TTC (radio 1 TX) | 5 | 3250 |
TTC (radio 2 RX) | 95 | 65 |
TTC (radio 2 TX) | 5 | 3250 |
EPS | 100 | 320 |
BAT (idle) | 90 | 0 |
BAT (heater full) | 10 | 5000 |
Antenna (deployment) | 0 | 1800 |
Antenna (deployed) | 100 | 35 |
Payload EDC | 0 | 1250 |
Radiation instrument | 100 | 1000 |
Average | 1762 mW |
Module | Duty Cycle (100%) | Power (mW) |
---|---|---|
OBDH | 100 | 115 |
TTC (radio 1 RX) | 95 | 65 |
TTC (radio 1 TX) | 5 | 3250 |
TTC (radio 2 RX) | 95 | 65 |
TTC (radio 2 TX) | 5 | 3250 |
EPS | 100 | 320 |
BAT (idle) | 90 | 0 |
BAT (heater full) | 10 | 5000 |
Antenna (deployment) | 0 | 1800 |
Antenna (deployed) | 100 | 35 |
Payload EDC | 0 | 1250 |
Radiation instrument | 100 | 1000 |
Average | 2387 mW |
Module | Duty Cycle (100%) | Power (mW) |
OBDH | 100 | 115 |
TTC (radio 1 RX) | 95 | 65 |
TTC (radio 1 TX) | 5 | 3250 |
TTC (radio 2 RX) | 95 | 65 |
TTC (radio 2 TX) | 5 | 3250 |
EPS | 100 | 320 |
BAT (idle) | 90 | 0 |
BAT (heater full) | 10 | 5000 |
Antenna (deployment) | 0 | 1800 |
Antenna (deployed) | 100 | 35 |
Payload EDC | 0 | 1250 |
Radiation instrument | 0 | 1000 |
Average | 1387 mW |
Operating mode | Power Budget |
---|---|
Nominal operation mode – EDC activated | 2.188 W |
Nominal operation mode – EDC deactivated | 1.563 W |
Emergency mode | 2.563 W |