1. DESIGN AND IMPLEMENTATION OF SOFTWARE SOLUTIONS
FOR SATELLITE GROUND SEGMENT,
WITH APPLICATION TO THE ESEO MISSION
PhD Candidate: Marco Bosco
Supervisor:
Prof. Paolo Tortora
Forlì - 06/05/2016
DOTTORATO DI RICERCA IN
MECCANICA E SCIENZE AVANZATE DELL’INGEGNERIA
CICLO XXVIII
Coordinator:
Prof. Vincenzo Parenti Castelli
Settore Concorsuale di Afferenza: 09/A1 Ingegneria Aeronautica, Aerospaziale e Navale
Settore Scientifico Disciplinare: ING-IND/05 Impianti e Sistemi Aerospaziali
Alma Mater Studiorum – Università di Bologna

2.  Introduction to Satellite Ground Segment
 The European Student Earth Orbiter (ESEO) Project
 Ground Segment
 Forlì SDR-based Ground Station
 Mission Control System: S/C M&C, TM Analysis, TMTC DB, Automated
Procedures, Satellite Simulator
 EUMETSAT Ground Stations Software Solutions
 Ground Station Analysis and Reporting Tool (GSAR)
 Satellite Passes and Conflicts Engine (SPACE)
 Ground Station Centralised Monitoring and Control Simulator
 Conclusions
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Ground Station Network
 Antenna pointing
 RF and BB equipment
Mission Control System
 Flight Dynamics System
 Flight Operations System
 Mission Planning
 Monitoring & Control (RT &
Offline)
 Archiving
 S/C Simulator

4. 07/06/2016 4
Jan 2013 Nov 2013 Jun 2015
Phase B Phase C Phase D
Kick-off  PDR  CDR 
 Microsatellite mission to SS LEO
 Sponsored by ESA Education Office
 9 universitities involved
 About 200 students
 Lecture courses and internship
opportunities (18 ECTS)
 System prime contractor: ALMASpace
Phase E
Launch
2017

5. 5
Mission objectives:
 Taking pictures of Earth
 Measuring radiation levels
 Testing technologies for
future education satellite
missions.
07/06/2016
Semi-major axis 6904.82699 km
Eccentricity 0.00134790
Inclination 97.47884º
Ascending Node 137.34203º
Argument of Perigee 67.74183º
True Anomaly 292.25995º
Mass 50 kg
Dimension 33x33x63 cm
ESEO Platform

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ROTOR
USRPN210
Serial
1GB
Ethernet
UDP
ESEOPlatform
GSM
MUNICH
Serial
1GB
Ethernet
UDP
GSF2
Serial
1GB
Ethernet
UDP
GSF1
ROTOR
Serial
Serial
GSV VIGO
AMSAT COMMUNITY
WORLDWIDE
SatNet
UDP
MCS PC
JSON-RPC
Over HTTPS
AMSAT Data
DataBase
Server
ODBC
JDBC
TMTC
AMSAT
Web
Services
Protocol
MCS Satnet
Client
HSTX
GS SatNet
Client
LabVIEW
ROTOR
USRPN210
ROTOR
USRPN210
Engineering
Data
Science Data
FORLI
ICOM+TNC
Internet
SYNC
Engineering
Data
Users
LabVIEW Data
Dashboard App
Internet
AMSAT-UK
University of Wroclaw
SITAEL
TU Munchen
University of Vigo
University of Bologna
Orbitron
GS SatNet
Client
GS SatNet
Client
GNURadio
Orbitron
Gpredict
LabVIEW
GS SatNet
Client
GNURadio
Orbit
Propagator
ESEO teams
Important collaboration
among universities
Ground Station Network

7. AX.25 radio amateur communication protocol preferred over CCSDS for its
simplicity and lower overhead to comply with the low bitrate and bandwidth.
07/06/2016 7
RSSI (dBm) average interference 6-11/8/2014
A shortened version of Reed-
Solomon coding was added
to the SDR software.
𝑡=(𝑛−𝑘)/2=8
This protocol has been fully
implemented and tested in
LabVIEW
First Byte I frame structure
Flag Address Control PID Info FCS Flag
01111110 14 Bytes 2 Bytes 1 Byte N Bytes 2 Bytes 01111110

8. ALMASat-1 (classical GS)
07/06/2016 8
ESEO (SDR-based GS)
To/From Antenna
To/From Antenna
 Wide frequency coverage(400-4400
MHz)
 Large bandwidth (40 MHz)
 Highly flexible (modulation scheme,
communication protocol)
 Full duplex transceiver
 Maximum output power 100 mW
Band Range (MHz)
2 m 144.0-146.0
70 cm 430.0-434.0
435.0-438.0
23 cm 1240.0-1245.0
1270.0-1298.0
HPA
USRPN210 + SBX
Coaxial
1 GB
Ethernet
Coaxial
Coaxial
SC tracking SW
LabVIEW SW
Analog radio
Modem
CI-V Level
Converter
Serial
Serial
Coaxial Coaxial
S/C tracking SW
SDR LabVIEW SW
ICOM 910H frequency coverage

9. 07/06/2016 9
TX:
 Digital to Analog Conversion
 RF Upconversion
RX:
 RF Downconversion
 Analog to Digital Conversion
TX:
 Modulation
 AX.25 encoding
 BB transmission
RX:
 Signal Display (Spectrum, Waterfall, ..)
 Signal Recording
 Demodulation
 AX.25 decoding
1 Gb/sUSRP N210 + SBX
NI-USRP Toolkit
(Driver SW)
NI-Modulation Toolkit
(Application SW)

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 Orbitron DDE connection for Doppler correction
The application is based on five parallel loops and queue operations
functions:

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The application is based on five parallel loops and queue operations
functions:
 Signal acquisition and display

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The application is based on five parallel loops and queue operations
functions:
 Signal IQ data recording in binary files

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The application is based on five parallel loops and queue operations
functions:
 Signal demodulation, AX.25 decoding and UDP connection

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The application is based on five parallel loops and queue operations
functions:
UDP connection, AX.25 encoding, signal modulation and transmission

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Five configuration parameters for SDR:
 Device name: IP address of USRP device
 Antenna port
 Carrier frequency: in the range 400-4400 MHz.
 Gain: is the amplification of signal
 Fetch size: samples N acquired at each iteration
𝐹𝑒𝑡𝑐ℎ 𝑇𝑖𝑚𝑒 = 𝐹𝑒𝑡𝑐ℎ 𝑆𝑖𝑧𝑒 𝐼𝑄 𝑟𝑎𝑡𝑒

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Five configuration parameters for SDR:
 Device name: IP address of USRP device
 Antenna port
 Carrier frequency: in the range 400-4400 MHz.
 Gain: is the amplification of signal
 Fetch size: samples N acquired at each iteration
𝐹𝑒𝑡𝑐ℎ 𝑇𝑖𝑚𝑒 = 𝐹𝑒𝑡𝑐ℎ 𝑆𝑖𝑧𝑒 𝐼𝑄 𝑟𝑎𝑡𝑒

17. 07/06/2016 17
Five configuration parameters for SDR:
 Device name: IP address of USRP device
 Antenna port
 Carrier frequency: in the range 400-4400 MHz.
 Gain: is the amplification of signal
 Fetch size: samples N acquired at each iteration
𝐹𝑒𝑡𝑐ℎ 𝑇𝑖𝑚𝑒 = 𝐹𝑒𝑡𝑐ℎ 𝑆𝑖𝑧𝑒 𝐼𝑄 𝑟𝑎𝑡𝑒

18.  Frequency (437 MHz downlink, 435.2 MHz uplink)
 Modulation (non-coherent 2-GFSK)
 Bit rate (9600 and 4800 bps)
 Communication Protocol (Packet detecting, Bit
stuffing, G3RUH Scrambling, NRZ to NRZI, CRC-16-
CCITT-1021)
07/06/2016 18
Step
Attenuator
SMA cable SMA cable
USRPN210
+SBX
LabVIEW
1 GB
Ethernet
SDR CHANNEL
CC1020
TXRX
IAR Embedded
Workbench
AVR
JTAGICE
Flat cable USB
TMTC

19.  Connected to the S/C DB
 TC selection
 TC stack
 TC Ack
 TTC timestamp
 UDP connection
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 TM packets and data display
 On-board schedule display
 Automatic e-mail warnings

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HKTM parameters display:
 Engineering values
• Numbers
• Strings
 Global parameters
• On/off
• Errors
SET TC parameters

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 Raw and EU TM data retrieval
from DB by datetime range.
 Trend Analysis
 Statistical Analysis
 Data can be saved to
spreadsheet files.
 Event structure

22.  About 500 TM parameters and 500 TC for equipment and payloads
 Developed in MySQL to store:
 TC list
 TC history
 TM parameters
 TM history
 Acknowledgment messages
 Users privileges definition
 Backup strategy
 Flat (Spreadsheet-like) tables
for TM values
07/06/2016 22
NI LabVIEW Database Connectivity Toolkit
Field prefix address type description
Type char(3) varbinary(2) binary(1) varchar(100)
prefix hex(address) hex(type) description
ACS 0106 10 ACS ITEMS ON
HPC 02 01 PMU MAIN OFF
Param1 Param2 … Param N-1 Param N Timestamp
Param Name (Key) Value Timestamp

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437 MHz GFSK
QueueEthernet
Queue
SDR PC
TM data
Extraction
ODBC
TM storing
MCS PC
HKTM post-
processing
TM packets
history
ODBC
ODBC
Queue
DemodSignal.bin
Demod
Signal
Record
Signal
Acquistion
AX.25
decoding
UDP
AX.25
decoding

24. 07/06/2016 24
435,2 MHz GFSK
Ethernet
SDR PC
MODSignal
Transm
MCS PC
TC packet
Assembling
TC storing
ODBC
TC List
ODBC
TC history
ODBC
AX.25
encoding
UDP
Script.m FOP.xls
TC packet
Assembling
ODBC
Automated Procedures:
 Spreadsheet file: Step, Operations, TC, Data,
Description, TM, TM data, Display
 Actions:
• Telecommanding (Send&Verify, Optional
Send, Send TTC, Send HPC)
• Telemetry Monitoring (Check, Monitor)
• Control Structures (Wait for, Goto, If, etc..)
• Select Display

25. 07/06/2016 25
S/C M&C
SDR Software
S/C AOCS and EPS simulator
TMTC Interface
TXRX, OBDH simulator
TC packet TM packet
IQ data
S/C variables (SET)
TC packetTM packet
IQ data
435.2 MHz GFSK signal
437 MHz GFSK signal
MCSPCSDRPC
S/CSimulatorPC
1 GB
Ethernet
RF signal
UDP
Simulink
S/C variables (GET)

26. Tools for testing:
 LabVIEW VI Analyzer
 LabVIEW Unit Test Framework
07/06/2016 26
Items to examine:
 Correctness of implementation
 Interaction with other components
 Robustness and error handling
 Conformance to coding standards/practices
 Readability
 Maintenability
 Reusability
 Completness

27. 07/06/2016 27
2 Command and Data Acquisition GS
 Svalbard (78° N)
 Metop-A/B, LEO satellites (817 km)
 L, S, X-Band
Primary Ground Station (PGS) antennae
 13 m dish in Usingen (near Frankfurt)
 L, S-band for uplink/dowlink
 Meteosat Second Generation (MSG) programme

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TM Propagator client CDA mimic display
For real-time monitoringFor post processing
and trend analysis
GSAR
Almost 2000 TM parameters for each
GS at higher rate during a S/C pass

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 Periodic reports are available as
html pages on a web page through
a calendar widget.
 Reports can be configured through
an XML template file.
 Widgets to be inserted are coded
in python
 Reports are generated periodically by
automated tasks
Schedule Activity Template Widgets TM data
FD data
Parameter
definition

30.  Ground Station TM data + Flight Dynamics data
 Antenna azimuth and elevation
 𝐸 𝑏/𝑁0 and Tracking RX level for L,S,X-band
07/06/2016
 Back to search events
30
M01 Orbit 15907 Eb/N0 (dB) Track RX Level (dBm) BTSE
BTSE vs AzEl

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Pass Duration (s) Max Elevation (deg)

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Conflict-free schedule for a satellite fleet over a GSN
NOAA-19 blind orbits support from Svalbard GS

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S/C G/S No. of orbits
TCA Error [s] Max El Error [deg]
Mean Max Mean Max
NOAA19
Svalbard 197 5.2 12.9 0.3 3
Fairbanks 155 5.6 16.1 0.2 2
Wallops 83 4.3 13.4 0.2 3
METOP-A
Svalbard 171 7.6 11.8 0.2 3
Fairbanks 135 4.7 13.4 0.1 4
Wallops 71 3.5 10.8 0.1 2
METOP-B
Svalbard 199 4.5 11.5 0.2 3
Fairbanks 156 5.1 12.5 0.1 2
Wallops 82 3.9 12.6 0.3 3
Comparing pyorbital (top) and pyephem (bottom) results accuracy
S/C G/S No. of orbits
TCA Error [s] Max El Error [deg]
Mean Max Mean Max
NOAA19
Svalbard 197 0.4 1.0 0.0 1
Fairbanks 155 0.3 1.0 0.0 0
Wallops 83 0.3 1.0 0.0 0
METOP-A
Svalbard 171 0.3 1.0 0.0 1
Fairbanks 135 0.3 0.8 0.0 0
Wallops 71 0.4 1.0 0.0 0
METOP-B
Svalbard 199 0.4 1.1 0.0 1
Fairbanks 156 0.4 1.0 0.1 2
Wallops 82 0.4 1.0 0.3 3

35. 3 TCP ports: Monitoring, Control, Info
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Ground
station
Low
Level
M&C
Telemetry Request
Ground
station
High
Level
M&C
Telemetry Response
Telemetry Points
Authentication
Authentication
Event Message
Schedule Info
RefreshSchedule Info
Message
Event Response
Event Request
Command
Command Acks
OPS site GS site
A Simulator is required for the
procurement of a GS M&C system.
Device Simulator by Finland Space SystemsCommunication protocol from ICD

36. 07/06/2016 36
Interface Module
Ground Station
M&C System
Command Ack
Module
Command Module
Monitoring Packet
Request Module
Monitoring Packet
Module
ReqTCAck TM
Ack TM ReqTC
Send Mon PktSend Ack Pkt Set Parameter
 Macros coded in Java, triggered by:
 Message reception or transmission
 Time
 System configuration based on XML parsing operations (DOM)
 Code implementation based on XSD files
 Clear and simple GUI for testing
 Successfully tested
 Delivered for MTG ground station
M&C system procurement

37. Telemetry points
messages
07/06/2016 37
Acknowledgment
messages history
Events
messages history

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These software solutions will be used for ESEO operations and can be
easily adapted to future educational satellite missions:
SDR for ESEO TMTC ground station
ESEO Monitoring and Control system
HKTM Data Analyser
TMTC interface for a MATLAB/Simulink-based Satellite Simulator
These software solutions, designed, implemented and tested, are
currently used by ground stations engineers at EUMETSAT:
 Ground Station Analysis and Reporting Tool (GSAR)
 Satellite Passes and Conflicts Engine (SPACE)
 Ground Station Centralised Monitoring and Control Simulator

39. 3907/06/2016
 Courses and Seminars:
 Applicazioni e Tecniche di Telecomunicazioni, Prof. Vanelli-Coralli, 6 CFU, 2012-2013.
 Laboratorio di Telecomunicazioni, Prof. Vanelli-Coralli, 3 CFU, A.A. 2012-2013.
 Uncertainty analysis for engineers, Prof. Alfredsson, Dr. Segalini, Prof. Talamelli, Dec.
2013.
 Conferences and Workshops:
 European Ground System Architecture Workshop (ESAW 2013) in ESA/ESOC,
Darmstadt 18-19 Jun 2013.
 IEEE International Workshop on Metrology for AeroSpace in Benevento (29-30 May
2014).
 ITU Symposium and Workshop on small satellite regulation and communication
system in Prague, 2-4 Mar 2015.
 European Ground System Architecture Workshop (ESAW 2015) in ESA/ESOC,
Darmstadt 16-17 Jun 2015.
 3rd IAA Conference on University Satellite Missions and CubeSat Workshop &
International Workshop on Lean Satellite Standardization in Rome, 30 Nov – 4 Dic
2015.

40.  M. Bosco, D. Cinarelli, P. Tortora: ‘Alma Mater Ground Station transceiver: A
software defined radio for satellite communications’ MetroAeroSpace
Proceedings, May 2014.
 P. Tortora, M. Bosco, D. Cinarelli, D. Bruzzi, N. Melega: ‘Soluzioni Innovative per il
Ground Segment di Small Satellites’ Le Tecnologie Nazionali per Mini e Micro
Satelliti: Idee, Progetti e Prospettive 1° Workshop Nazionale, Capua, 20-22 July
2015.
 M. Bosco, P. Tortora: ‘ESEO Ground Segment Software Solutions: Design,
Implementation and Testing’, 3rd IAA Conference on University Satellite Missions
and CubeSat Workshop & International Workshop on Lean Satellite
Standardization in Rome, 30 Nov – 4 Dec 2015.
 D. Modenini, M. Bosco, A. Locarini, P. Tortora: ‘Space Engineering and Small
Satellites Educational Activities at University of Bologna’, 1st Symposium on
Space Educational Activities Padua, 9-12 Dec 2015.
07/06/2016 40

41. Thank you for your attention