Reception

We are inviting all radio-amateurs and satellite enthusiasts around the world to help us receive QUBIK twins while in orbit. This is what you need to know about reception of QUBIK signals:

Beacons

QUBIK-1 and QUBIK-2 will be beaconing 30 minutes after deployment at the same frequency (this is part of the experimentation) 435.240 Mhz.

The satellites are programmed with a specific beaconing pattern to enable various Experiments for LEOP orbit determination and identification.

The default beaconing pattern is as follows:

PA

Power

Telemetry Type

Modulation

Encoding

Baud

ms

sec delay

1

1

-2

Basic

GFSK

RS

9600

220

30

2

1

-2

Basic

BPSK-RES

CC12RS

9600

1300

30

3

1

-2

Basic

GFSK

RS

9600

220

30

4

1

-2

Basic

GFSK

CC12RS

9600

400

30

5

1

-2

Basic

GFSK

RS

9600

220

30

6

1

-2

Basic

BPSK-RES

CC12RS

9600

1300

30

7

1

-2

Basic

GFSK

RS

9600

220

30

8

1

-2

Basic

GFSK

CC12RS

9600

400

30

9

1

-2

Basic

GFSK

RS

9600

220

30

10

1

-2

Basic

BPSK-RES

CC12RS

9600

1300

30

11

1

-2

Basic

GFSK

RS

9600

220

30

12

0

15

Basic

RILDOS

RAW

125000

2500

30

All modulations regardless of their encoding and baud rate are CCSDS TM Space Data Link packets with a specific payload (the actual telemetry).

The Telemetry structure is as follows:

Category

Field

Details

Size

Unit

Power

Current

Instantaneous

16

s2

mA

Power

Voltage

Instantaneous

16

u2

mV

Power

Die Temperature

Instantaneous

8

s1

C

Power

Battery Temperature

Instantaneous

8

s1

C

Power

Current

Min

16

s2

mA

Power

Voltage

Min

16

u2

mV

Power

Battery Temperature

Min

8

s1

C

Power

Current

Max

16

s2

mA

Power

Voltage

Max

16

u2

mV

Power

Battery Temperature

Max

8

s1

C

Power

Current

Average

16

s2

mA

Power

Voltage

Average

16

u2

mV

Power

Battery Temperature

Average

8

s1

C

Power

Time to empty

16

u2

min

Power

Remaining capacity

16

s2

mAh

Power

Full capacity

16

s2

mAh

Power

State of charge (%)

8

s1

%

Antenna

Antenna Deploy Test voltage

Acquired once on antenna deployment

16

s2

mV

Antenna

Antenna Deploy Test current

Acquired once on antenna deployment

16

s2

mA

Antenna

Antenna Deploy Test result

Acquired once on antenna deployment

8

u1

n/a

Antenna

Antenna Deploy average voltage

Acquired once on antenna deployment

16

s2

mV

Antenna

Antenna Deploy average current

Acquired once on antenna deployment

16

s2

mA

Antenna

Antenna Deploy duration

Acquired once on antenna deployment

8

u1

s

Antenna

Antenna Deploy status

Acquired once on antenna deployment

8

u1

n/a

Antenna

Antenna Deploy retries

Acquired during antenna deployment

8

u1

n/a

MCU

Uptime

32

u4

secs

MCU

Internal Temperature

8

s1

C

MCU

RTC Battery Voltage

16

u2

mV

Operational

First Deploy

8

u1

n/a

Operational

Antenna first Deploy

8

u1

n/a

Statistics

Reasons of reset

8

u1

Statistics

Dropped Frames

16

u2

Statistics

low_power_counter

16

u2

Statistics

independent_watchdog_counter

16

u2

Statistics

software_counter

16

u2

Statistics

brownout_counter

16

u2

Status

Power Save

8

u1

n/a

Status

Power Monitor Fail

8

u1

n/a

OSDLP

CLCW per VC

160

20

Radio

Tx Frames

16

u2

Radio

Rx Frames

16

u2

Radio

Rx corrected bits

32

u4

Radio

RSSI

8

s1

dB

Radio

Frequency tracking

16

s2

Radio

AGC

8

s1

Radio

Data rate Tracking

32

s4

Radio

Phase Tracking

16

s2

Radio

RF Freq Tracking

32

s4

Radio

Rx-Tx turnaround

16

u2

ms

The kaitai struct for the whole PDU can be found here .

How to receive

The easiest way to receive is by setting up a SatNOGS station. SatNOGS is already setup for QUBIK tracking, demodulating, decoding and forwarding to the appropriate dashboard at dashboards.satnogs.org . Learn how to setup a SatNOGS station.