Patron of the mission Nanoracks
Mission organizers Vilniaus universitetas
Mission partners lrt.lt Delfi.lt

HAM Radio

Information for LituanicaSAT-1 signal reception and operation

  • FM Radio Beacon: 437.275 MHz reception. Call sign: LY5N
  • FM Voice Repeater: 145.950 MHz transmission (PL 67 Hz CTCSS) 435.180 MHz reception. Call sign: LY5N
  • AX.25 Packet Radio: 145.850 MHz uplink; 437.550 MHz downlink; 9600 baud FSK, FM .

Data submission form

 

 

Information about the structures of data protocols of LituanicaSAT-1

LituanicaSAT-1 FM Morse beacon:

 

The LituanicaSAT-1 nanosatellite carries a FM Morse beacon which periodically broadcasts it’s operational parameters to all the listeners on the ground. The beacon transmits data every 30 seconds at 437.275MHz with a power of 100mW and it’s signal is basically a FM modulated 600 Hz beep. FM modulation was chosen to support widely available cheap handheld radio receivers.

Here is the breakdown of the data which is transmitted to the ground during every cycle:

LY5N

V

PV1

PV2

PV3

BV

C

PC

SC

T

TS

BT

S

CH

 

  • LY5N – this is the amateur radio designated callsign of the satellite
  • V indicates the voltage part where data is represented in power of (milli)volts:
  1. PVx is the photovoltaic voltage of all three solar panel channels mV × 10-1;
  2. BV stands for battery voltage, mV× 10-2;
  • C indicates the current part:
  1. PC indicates input current from solar panels, mA
  2. SC indicates total system current, mA
  • T indicates the temperature part:
  1. TS is the temperature digit sign, either positive (P) or negative (N)
  2. BT indicates the temperature of the battery, in Celsius degrees
  3. S indicates the EPS subsystem output channel status mask (converted to decimal)

Eventually, sample data transmission could look like this: LY5N V 43 39 40 77 C 7 63 T P 26 S 38

Sample sound, which illustrates above data, can be played here: Beacon Sound Sample

Beginner listeners should also consider the Doppler effect and tune the reception frequency accordingly, as it will deviate approx. -10KHz to +10KHz throughout the orbital pass.

 

LituanicaSAT-1 Telemetry Packet Structure:

 

1 Byte 4 Bytes 60 Bytes 165 Bytes
Marker Time HK data Attitude data
Below is the detailed specification of the packet structure
NOTE:
All integers are in little-endian.
Structure defined here describes payload of an AX.25 frame
Telemetry is sent using UnNo.ed (UI) AX.25 frames every 15 s
Element Field Size Type Comments
LS1_TM Marker 1 byte unsigned integer Constant, 11100100 (binary)
Time 4 bytes unsigned integer Centi-seconds (1s / 100).
Housekeeping data 60 bytes See LS1_HK
Attitude 1 take 55 bytes See LS1_ATT First read.
Attitude 2 take 55 bytes See LS1_ATT Read after 100 ms
Attitude 3 take 55 bytes See LS1_ATT Read after next 100 ms
LS1_HK Power Mode 4 bits unsigned integer
Sat Mode 4 bits unsigned integer
EPS TM 43 bytes See LS1_EPS EPS housekeeping packet
Helium100 TM 16 bytes See LS1_HE Transceiver housekeeping
LS1_ATT HMC5883L Magnetometer 7 bytes See LS1_MAG Raw data from sensors.
MPU6000A Accelerometer 7 bytes See LS1_ACCEL Raw data from sensors.
MPU6000A Gyroscope 9 bytes See LS1_GYRO Raw data from sensors.
MPU9150A Accelerometer 7 bytes See LS1_ACCEL Raw data from sensors.
MPU9150A Gyroscope 9 bytes See LS1_GYRO Raw data from sensors.
AK8975 Magnetometer 7 bytes See LS1_MAG Raw data from sensors.
L3GD20 Gyroscope 9 bytes See LS1_GYRO Raw data from sensors.
LS1_EPS PV1 16 bits unsigned integer Photo-voltaic input no. 1 [mV]
PV2 16 bits unsigned integer Photo-voltaic input no. 2 [mV]
PV3 16 bits unsigned integer Photo-voltaic input no. 3 [mV]
PC 16 bits unsigned integer Total photo current [mA]
BV 16 bits unsigned integer Battery voltage [mV]
SC 16 bits unsigned integer Total system current [mA]
TempBC1 16 bits signed integer T of boost converter 1 [degC]
TempBC2 16 bits signed integer T of boost converter 2 [degC]
TempBC3 16 bits signed integer T of boost converter 3 [degC]
TempOB 16 bits signed integer T of onboard battery [degC]
BattTemp1 16 bits signed integer not used
BattTemp2 16 bits signed integer not used
Latchup50V1 16 bits unsigned integer No. of latch-ups on ch. 5V1
Latchup50V2 16 bits unsigned integer No. of latch-ups on ch. 5V2
Latchup50V3 16 bits unsigned integer No. of latch-ups on ch. 5V3
Latchup33V1 16 bits unsigned integer No. of latch-ups ch. 3.3V1
Latchup33V2 16 bits unsigned integer No. of latch-ups ch. 3.3V2
Latchup33V3 16 bits unsigned integer No. of latch-ups ch. 3.3V3
Reset 8 bits unsigned integer Cause of last EPS reset
Bootcount 16 bits unsigned integer No. of EPS reboots
SwErrors 16 bits unsigned integer No. of errors eps software
PPTMode 8 bits unsigned integer 0=HW, 1=MPPT, 2=SWPPT
ChannelStatus50V1 1 bit boolean Depl. Mech., 1=on, 0=off
ChannelStatus50V2 1 bit boolean Rx + Tx, 1=on, 0=off
ChannelStatus50V3 1 bit boolean FM Transp., 1=on, 0=off
ChannelStatus33V1 1 bit boolean FM Beacon, 1=on, 0=off
ChannelStatus33V2 1 bit boolean OBC, 1=on, 0=off
ChannelStatus33V3 1 bit boolean Radio Rx, 1=on, 0=off
ChannelStatusQS 1 bit boolean not used
ChannelStatusQH 1 bit boolean not used
LS1_HE OpCounter 16 bits unsigned integer
MSP430Temp 16 bits signed integer
TimeCount1 8 bits unsigned integer
TimeCount2 8 bits unsigned integer
TimeCount3 8 bits unsigned integer
RSSI 8 bits unsigned integer
BytesReceived 32 bits unsigned integer
BytesTransmitted 32 bits unsigned integer
LS1_MAG X 16 bits signed integer
Y 16 bits signed integer
Z 16 bits signed integer
Gain 8 bits unsigned integer
LS1_ACCEL X 16 bits signed integer
Y 16 bits signed integer
Z 16 bits signed integer
Gain 8 bits unsigned integer
LS1_GYRO X 16 bits signed integer
Y 16 bits signed integer
Z 16 bits signed integer
Temp 16 bits signed integer
Gain 8 bits unsigned integer