Reference ID: -Rev: 1.0Status: ReleasedUpdated: 2-Apr-2021by: Tayodit P.

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Ground Segment Overview Basic and Introduction

Tayodit PlaidoungProduct Manager & Ground System Engineer for THEOS-2 SmallSAT/MMGS

Basic Introduction

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Objective

• The purpose of this session is to give an understanding of

• The overview of ground segment

– Key elements that comprise ground segment on the ground station i.e. the antenna system and RF equipment

– General ground system and the interfaces typically encountered for interaction with the antenna systems

– Ground segment components and functionality

– Interface to other system

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AcronymCONOPS Concept of Operation

GAF Geolocation Ancillary File

MOC Mission Operation Centre

MPS Mission Planning System

SEET System End to End Test

SOC Spacecraft Operation Centre

SSTL Surrey Satellite Technology Ltd

TC Telecommand

TM Telemetry

TT&C Telemetry, Tracking and Command

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Responsibility

• The ground segment team responsible for design, develops, installs and support ground segments for use with SSTL satellites.

Technical skill/Knowledge

• Space segment introduction• Satellite mission design• Ground system design• Satellite operation• Familiarisation on SSTL ground segment • Engineering process (SSTL or other standard)• Network engineering• IT platform equipment• Software development (C/C++, JAVA, JavaScript, python)• Software validation and verification• Software Installation and Implementation

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Overview Value Chain

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System High-levelSpace Segment

Ground Segment

SOC MOC Antenna Ground Station

Launch Segment

X-Band Image dataS-Band TT&C

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Satellite Operation CenterData receiving & Image Ground

Segment

Telemetry Data

Telecommand

Image Shooting

Customer

Mission

Planning Application

Satellite

Command

Imagery Raw Data

Operation Cycle

Customer

Service

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Example Mission Control

NASA Mission Control CenterJohnson Space CenterHouston, Texas, USA

ESA European Space Operations Centre

(ESOC) Darmstadt, Germany

GISTDASatellite Control Room

Siracha, Chonburi

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[Credit]

https://en.wikipedia.org/wiki/Mission_control_center[Credit]

https://en.wikipedia.org/wiki/European_Space_Operations_Centre

2,500 Km

Coverage Area

Sriracha Station

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Ground Segment Overview

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Ground Segment Overview for SmallSAT• Main components;

– Ground Station

o Includes the ground antenna and front end RF equipment

o Includes software for configuration and control of the antenna and RF equipment

– Spacecraft Operations Centre (SOC)

o Includes software to command satellite, display telemetry

o Flight Dynamics System

– Mission Operations Centre (MOC)

o Mission Planning

o Image processing

o Image Catalogue

o Payload File Archiving

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SmallSAT Ground Segment Architecture

RF EQPT

Modem(Cortex CRT)

RF EQPT

Demodulator (VHR) SDP

S-Band Connector Application

(SSTL Proprietary)

STA-Server(Saratoga)

S-Band System

X-Band System

SSTL component

SOC

MOC

S-Band - RX : 2200-2300 MHz- TX : 2025-2120 MHz

X-Band - RX : 8400 -8450 MHz

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ARQ

ASP

(GsnControl)

THEOS- 2 Sm allSA T

Multi GroundstationManagement System

ADP

Mission

Interface

Mission

Broker

Satellite Planner

Scheduler

Terra

MPS Database

ASP

ASP Database

AOCS Data Storage

Image Data Storage

Geometric Processor Catalogue

AOCS Metadata XML file (23)

Contact schedules (8)

Track

(GsnControl)

GSN Exec

Ephemeris

SaratogaWin

(GsnData)

WinIdle

(GsnData)

Script

(GsnTLM)

WinIdle

(GsnTLM)Binary schedules

(OUT files) (17)

DispTLM

Async Version

(GsnTLM)

DispTLM

IP version

(GsnTLM)

Low Speed

Server

(GsnData)

Archive Interface

Archive

Archive Database

SaratogaWin

(STA Server)

S-Band Connector

IP Router

FTP

Dropbox

TGS (12), TMS (13)

File transfer

Acquisition schedules

XML (16)

Javelin

(FDS)GPS Logs (1)

TLE(2)

TLE(4)TLE (4)

Catalogue Interface

Spacecraft Schedule Data (18)

Availability Schedule (6)

Availability Schedule (7)

Contact schedules (9)

Antenna Contact Schedule (10)

Real-time Telemetry (11)

Real-time Telemetry (11)

TGS (12), TMS (13)

Acquisition schedules

XML (15)

TDS (19)

TDS (20)

Raw Image Data (21)

GAF Data (22)

TDA (24)

TDA (25)

GISTDAFDS

TLE(2)

GPS Logs (1)

GISTDAMission Planning

(OPTEMIS)

SPS Interface

(Sensor Planning Service)

Catalogue

Catalogue interface

System Block Diagram

Ref: SmallSAT SSTL Ground System Architecture -rev0.8 (draft)

SSTL-SOC

SSTL-MOC

GsnControl GsnData GsnTLM GsnArchive

Mission Planning Image Processing

S-Band

Antenna Ground Station

X-Band

MMGS

MMGS

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Spacecraft Operations Centre (SOC)

• SOC is monitoring and controlling thespacecraft through a set of commercialcomputers that are used for spacecraftTT&C operations.

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SOC Components• Tracking and Scheduling• Commanding

– Type of command • Low level commanding e.g. critical command to serial protocol • High Level commanding e.g. based on IP protocols

• Telemetry (TM)– Type of TM

• Low Level Telemetry e.g list of critical telemetry• High Level Telemetry e.g. Real time telemetry, Historical telemetry (record telemetry)

• Doppler• Spacecraft-Ground Transfer :

– Payload Files– OBC Files

• Time Synchronisation• Payload Scheduling

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Mission Operation Centre

• The MOC is used to plan spacecraft imaging operations and process andaccess downloaded mission payload data.

• It consists of payload planning and image processing software applications.

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Mission Planning Server• Imaging tasks are planned by

operators using the Mission Planning System (MPS)

• Generates spacecraft activity schedules

Mission Planning Server

ling

Mission Planner

GINs

Flight Dynamics System

(Ephemeris)

Mission Broker

Acquisition Schedules

Input Output

Mission Interface

Mission Planer

Imaging tasks

Availability Schedule

TLE

TDSText-based Downlink

Antenna Contact

Schedules

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Image Processing Server• Raw image data from ViaSat SDP

to the product subsystem which Radiometric processed by Terra and archives

• Transfer AOCS Logs data (Geo-location Ancillary File-GAF) to ADP, in order to pass processed AOCS metadata XML to the geometric processor

Image Processing

Serverling

Image data

Antenna System

Terra

MMGS

(Geometric Processor)

Input Output

AOCS log data ADP

AOCS Data Storage

Raw

GAF

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Antenna Components – Mechanical• Pedestal

• Dish

• Motors

• Cabling and management

– Antenna Control Unit• SCU

– RF• Low Noise Amplifiers (LNA)

• SSPA

• D/C, U/C

• Waveguide/Feed system

– Environmental Sensors• GPS and Anemometer

• Wind

• Temperature

• Humidity

M&C Computers

GPS Antenna & Anemometer

LAN Hub

Cortex

SCU

ADU Box

SSPA

Local Box

Siren

Oil Pump

Grease Pump

GPS

D/CUP/C

Dehydrator

Servo Control Unit

Reflector & Feed

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S-band(WATER)

S-band(CGC)

X-band(ViaSat)

X-band(L3)

Antenna Location

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Antenna

S-band (WATER) X-band (VIASAT) X-band (L3)

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GISTDA Antenna Ground Station (Hexapod)

Reflector

Hexapod

Feed

- 6.1 m- Carbon fiber

- Prime Focus- RX : 2200-2300 MHz- TX : 2025-2120 MHz

- Program Track- EL : 0-180o

- AZ : 0-360o

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GISTDA Antenna Ground Station (3 Axis)

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Ground Station Design• RF

o Frequencies and bandwidth o The existing RF environment like, any in-band interferers?o Customer/State Agency engagement to resolve interference signals – some legal, some illegal

• Environmento The weather conditions like at the site?o High wind conditions? Rain? Dust? Sand? Significant temperature variations? Snow and Ice?

• Factors affecting antenna and ground station system selection– Geographical location that blocking line of sight– Modulation Schemes – FSK or BPSK uplink? QPSK or 8PSK X-Band downlink?– Performance – link budget coordination with RF Team– Multi Ground station Support?– CONOPS o Direct downlink broadcast mode? ARQ on uplink to handle dropped packets?o Support for other satellites?

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Ground Station Design (cont.)• Infrastructure

– Site infrastructure e.g. building design, electrical, air condition and construction

– Inter-building links as required (e.g. RF and IP LAN)

– IT Services – Internet access requirement, Email, FTP services

– Generate the facilities requirement documentation to cover electrical, air conditioning, civil engineering, Antenna mounting and load management, network, Internet, facilities etc.

• Networking Constraints

– Bandwidth estimation e.g, Gigabit infrastructure

– Inter-building links?

– Ground segment LAN as isolated or connected to customer LAN? Security constraints?

– Provision of remote access?

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Antenna Ground Station – DIGINEOCompatibility Test

MMGS Commissioning

SSTL scope

Installation and Integration Test Commissioning

Ready for SmallSAT

GSSTL FAT

Subsystem Test

MMGS scope

System Ready for Installation and Integration

A

MMGSSubsystemAcceptance

Test

GISTDAFacility

ReadinessReview

SSTL Hardware Inspection

SSTLPost Installation Test

SSTL OSAT

SSTL IOTR

Commissioning

SmallSATEnd-to-End Test

Network Test

Legend

DIGINEOOSAT

DIGINEOFAT

GINs Interface Test

MIXERs Interface Test

GIPS Interface Test

Mobile X-Band Interface Test(Incl. MIPS)

Common Interface Test

B

F

DIGINEO Ready for MMGS

integration

ReadyFor MainSAT

Antenna Ground Station – SmallSAT GS

Compatibility Test

DIGINEO Integration

SSTL GS Integration

MMGS-SSTL GSIntegration test

C

SSTL Ground SegmentReady for MMGS Integration

Ground System Ready for Commissioning

H

AIRBUSIOTR

Commissioning

AIRBUS scope

GISTDAscope

LRR

LRR

MMGS - DIGINEO Integration Test

D

E

DIGINEO-MMGS Integrated

Ready for LRR

SSTL GS-MMGS Integrated

Ready for LRR

SmallSAT Ground Segment Test Strategy

• SSTL FAT

• MMGS Subsystem Acceptance Test

• GISTDA Facility Readiness Review

Stage A: Subsystem

level test

Stage C: System Installation

• SSTL Ground Segment Installation and OSAT

• Including – Antenna Ground

Station Compatibility Test

– Network Test

Stage E: Integration

• Verify Interface between SSTL-MMGS

• Should be done before SEET

Stage G: LRR

Commissioning

• Should be done before SEET

• SmallSAT LRR

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THEOS-2 Ground System Network Diagram

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Water BuildingAIT Building

THEOS1 Control Room BuildingSat Building

Antenna systems

CGCS-band Antenna

WaterS-band Antenna

L3X-band Antenna

ViasatX-band Antenna

THEOS 2 THEOS 1 (CGS)SSTL MMGS

DedicatedInternet access

GISTDA SKPInfrastructure

GISTDABKK Network

Main Building

X-band L3

RF System

X-band VIASAT

RF System

S-BandWater

RF System

S-BandCGC

RF System

Layer 3 deviceSwitch or router tbd!!

DedicatedInternet access

DedicatedInternet access(CAT Provider)

KirunaVPN

THEOS 1 (IGS)

THEOS 1 (MPC)

• Physical Link Verification

• Routing Connection

GISTDA Facility Map

4.1 Image Acquisition andProduction

1. Space Centrariu2. AITBuilding

(Clean Room)

7. CGC S-Band Antenna (3 Fl.)

8. L3 X-Band Antenna

3. THEOS-1 Control Building

5. WATER S-Band Antenna

6. ViaSat X-Band Antenna

4.2 Data Centre

GISTDA BKK

Network

2.1 CCTV room

1.1 NOC room

1.2 Ground Server room

LAN (Clean room): 10

LAN (Office): 35

2.1 Cleanroom

Add SFP+ Cisco 10 Gbps (4 modules)

1 1

1

1

1

1

2

1

1

LAN (Acq. room): 10

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Inter-Network Test

Ground Segment Hardware Workflow

Workstation

Example of Ground Segment Rack

RF Rack

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[Credit] https://en.wikipedia.org/wiki/Data_center#/media/File:Datacenter-telecom.jpg

Thank you

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