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EISCAT Scientific Association

System and Subsystem Design Description

EISCAT3D_PfP

EISCAT Scientific Association System and

Subsystem Design Description EISCAT3D_PfP

2016-09-08

(45)

Table of Contents 1 SCOPE .................................................................................................................................... 3

1.1 IDENTIFICATION .............................................................................................................................. 3 1.2 SYSTEM OVERVIEW .......................................................................................................................... 3 1.3 PURPOSE ....................................................................................................................................... 4 1.4 REVISION HISTORY .......................................................................................................................... 5 1.5 APPLICATION .................................................................................................................................. 5 1.6 DEFINITIONS AND ABBREVIATIONS ...................................................................................................... 6

2 REFERENCES ........................................................................................................................... 7

3 SYSTEM-WIDE DESIGN DECISIONS .......................................................................................... 8

3.1 INTERACTIONS WITH SURROUNDING SYSTEMS ....................................................................................... 8 3.2 PHYSICAL ENVIRONMENT .................................................................................................................. 9 3.3 BEHAVIOURAL DESIGN .................................................................................................................... 10

3.3.1 Test Sub-array boot-up ................................................................................................... 12 3.3.2 Start an Experiment ........................................................................................................ 13 3.3.3 Transmit .......................................................................................................................... 14 3.3.4 Receive ............................................................................................................................ 15 3.3.5 Exit an Experiment .......................................................................................................... 16 3.3.6 Test Sub-array shutdown ................................................................................................ 17 3.3.7 Calibrate transmit chain ................................................................................................. 18 3.3.8 Calibrate receive chain .................................................................................................... 19 3.3.9 Warm Start Boot and re-boot ......................................................................................... 20 3.3.10 Cold Start Boot & re-boot ........................................................................................... 21

3.4 OVERALL DESIGN DECISIONS ............................................................................................................ 22

4 SYSTEM ARCHITECTURAL DESIGN ......................................................................................... 23

4.1 SYSTEM COMPONENTS ................................................................................................................... 23 4.1.1 General components ....................................................................................................... 24 4.1.2 Pulse and Steering Control Unit ...................................................................................... 25 4.1.3 Network Components ..................................................................................................... 27 4.1.4 Antenna Unit ................................................................................................................... 28 4.1.5 Time and Frequency Unit ................................................................................................ 30 4.1.6 Cables and Connectors .................................................................................................... 32 4.1.7 Transmit unit container .................................................................................................. 32 4.1.8 Climate monitoring equipment ....................................................................................... 33 4.1.9 TU Power Supply Container ............................................................................................ 33 4.1.10 Subsystem Manager Container .................................................................................. 33 4.1.11 Transmit Unit ............................................................................................................. 33 4.1.12 Instrument Container ................................................................................................. 36 4.1.13 First Stage Receiver Unit ............................................................................................ 37

4.2 CONCEPT OF EXECUTION ................................................................................................................. 40 4.3 INTERFACE DESIGN ......................................................................................................................... 40

4.3.1 Data model ..................................................................................................................... 40 4.3.2 EROS/Subsystem Manager Message Protocol ................................................................ 41

5 REQUIREMENTS ALLOCATION ............................................................................................... 43

6 NOTES .................................................................................................................................. 44

6.1 DESCRIPTION OF DIAGRAMS ............................................................................................................ 44



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1 Scope

1.1 Identification

This System and Subsystem Design Description (SSDD) applies to the EISCAT_3D

Test Sub-array, also called “Test Sub-array” throughout this document.

1.2 System overview

The Test Sub-array is a phased-array antenna radar system containing 91 crossed

dipole antenna elements, a beamformer, a receiver, a transmitter and other subsystems

for control, time-keeping et cetera. The purpose of the Test Sub-array is to serve as a

proof of concept for the planned EISCAT_3D incoherent scatter radar system.

Diagram 1: The whole system

This diagram displays the different subsystems of the Test Sub-array and displays,

where applicable, where the subsystems are located physically.

The instrument container houses:

Time and Frequency Unit

First Stage Receiver Unit

Climate monitoring Equipment

EISCAT_3D Test Sub-array

nc: Network Components cc: Cables and Connectors

au / a: Antenna Unit

ic: Instrument Container tuc: Transmit unit container

fsru: First Stage

Receiv er Unit

pscu: Pulse and

Steering Control

Unit

tfu: Time and

Frequency Unit

sm: Subsystem Manager

Container

: TU Power Supply Container

tu: Transmit Unit

cme: Climate monitoring

equipment : Power supply TU



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Pulse and Steering Control Unit

Subsystem Manager (specific for the Instrument Container)

The Transmit Unit Container contains the Transmit Unit.

The TU Power Supply Container contains the Power Supply for the Transmit Unit.

Also included in the Test Sub-array are Network Components plus Cables and

Connectors to connect the different subsystems and components.

Note that the diagram only displays the Test Sub-array subsystems. External systems

(e.g. Computing System which is located inside of the Instrument Container) are not

displayed.

The Test Sub-array is hexagonally shaped and the previously described containers are

placed underneath a steel structure ("Array Structure") which the Antenna Elements

are also mounted on.

Diagram 2: EISCAT_3D Sub-array Layout

The image shows a sketch, from above, of how the containers physically can be

placed in the Test Sub-array. It also shows how the Test Sub-array, in the future, can

scale to the full EISCAT_3D array. The sketch is not in scale and the measurements

of the containers are approximations.

1.3 Purpose

The purpose of this SSDD is to provide an overall description of the Test Sub-array

system, including its logical design as well as its physical architecture down to

subsystem level.

4m

3m

2.5m

1m

2.5m 2.5m



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1.4 Revision History

2016-06-28, issue 0.2

2016-06-29, issue 0.3 minor estetic updates

2016-08-12, issue 0.4 updates with new information for Antenna Unit

2016-09-06, issue 0.5 updates to include final Antenna Unit (AU) and revised Pulse

and Steering Control Unit (PSCU) details.

2016-09-08, issue 0.6 updates to include final Pulse and Steering Control Unit

(PSCU) details.

1.5 Application

This document may be used as information to the developers and suppliers during the

development, production, integration and verification processes for the Test Sub-array

subsystems and components. The SSDD may also be used for educational purposes.

To interpret the different types of diagrams displayed in this document, please see

section 6.1 Description of Diagrams, below, for further information.

Note that the SSDD is still under construction and its contents may change.



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1.6 Definitions and Abbreviations

Definition Description

AAF Anti-Aliasing Filter

ADC Analog to Digital Converter

CPU Central Processing Unit

dBm dBm (sometimes dBmW or decibel-milliwatts) is an

abbreviation for the power ratio in decibels (dB) of the

measured power referenced to one milliwatt (mW).

(Wikipedia)

EROS EISCAT Realtime Operating System

LNA Low Noise Amplifier

M & C Monitoring and Control

PfP Preparation for Production

ps picoseconds

RC Radar Controller

RF Radio Frequency

SFDR Spurious Free Dynamic Range (in operation frequency

band)

SNR Signal to Noise Ratio

SSDD System and Subsystem Design Description

SSPA Solid State Power Amplifier

VSWR Voltage Standing Wave Ratio

WR White Rabbit



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2 References

The systems engineering work is based on the following documents:

Reference Title

[RCM] EISCAT_3D Radar Control and Monitoring

Subsystem Report

[NGTD] EISCAT_3D: The next generation

international atmosphere and geospace

research radar Technical Description

[Impl] Implementation of EISCAT_3D Test Sub-

Array Final Version June 2016

[MD] Milestone Document MC-1

Test sub-array sub-systems and interfaces.

[SysML] SysML Distilled

[WRS] White Rabbit Specification: version 2.0

[WRSw] White Rabbit Switch: User’s Manual wr-

switch-sw-v4.2



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3 System-wide design decisions

This chapter describes the requested behaviour of the Test Sub-array and the context

it will operate in, including both the actual physical environment as well as the

surrounding systems that the Test Sub-array needs to interact with in order to provide

its assigned technical functions.

3.1 Interactions with surrounding systems

The Test Sub-array will interact with a number of systems external to the Test Sub-

array. These interactions are displayed on the activity diagrams presented in chapter

Behavioural design.

The following diagram displays the surrounding systems the Test Sub-array will have

interfaces to.

Diagram 3: Operational domain

The diagram above shows the operational domain, i.e. the EISCAT_3D Test Sub-

array and its surrounding systems.

Antenna Calibration Tower

The Antenna Calibration Tower will be used during end-to-end calibration runs, and

will either transmit or receive the RF signals that are sent through the receive

chain/transmit chain of the Test Sub-array. Any offsets (unexpected time delays) that

ibd [block] Operational domain [Operational domain]

Tromsö sitep74

p75

p73

p82:

TBD

: EISCAT_3D

Test Sub-arrayp74

p75

p73

p82:

TBD

: Antenna

Calibration

Tower

cs: Computing

System

: EROS

: EROS Power

switch

: Mains Power

1

Gb/s



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are discovered through the calibration test will be used as input to the beamformer for

example. The behavioural context of the Test Sub-array’s interactions with the

Antenna Calibration Tower is displayed on the calibrate diagrams in section

"Subsystem interaction".

Computing System

The computing system will, during the PfP phase, consist of a computer used to store

and process the measurement data from the First Stage Beamformer.

EROS

EROS (EISCAT real-time operating system) is an M&C software system that also

serves as the user interface of the Test Sub-array. EROS monitors and controls the

different subsystems through its communication with the Subsystem Managers that

are included in the subsystems. The communication consists of the exchange of

simple text messages.

EROS sends status commands inquiring about the health of the subsystems and also

sends non-time-critical control commands, for example commands related to system

startup and shutdown. These commands then initiate some kind of predefined

behaviour, e.g. activities being carried out and/or information being returned. EROS

can also receive unprompted notifications from the Subsystem Manager if it detects

any anomalies.

EROS will be located inside the main building at the Tromsö site and will be accessed

through a wide area network (currently 100 Mb/s communication link using fibre

Ethernet) connecting the Test Sub-array site to the Tromsö University network. The

Slow Ethernet will use a small part of this faster network.

EROS Power switch

The EROS Power switch is a remotely controlled independent networked power

switch that allows EROS to reboot SubMan, the software running on the Subsystem

Manager computer, see section Subsystem Manager for more information.

Mains Power

The power supply to the Test Sub-array site.

3.2 Physical environment

The site for the Test Sub-array is located in Ramfjordmoen outside of Tromsö,

Norway. Its climate has to be taken into consideration (risk of snow accumulation, et

cetera) when designing the different subsystems, and the parts of the system that have

direct interfaces with the environment also need to be resilient to the kind of wildlife

that can be expected at the site.



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3.3 Behavioural design

A smooth transition into the EISCAT_3D implementation phase as well as valuable

insights regarding system design and performance are expected through the

development and implementation of the Test Sub-array. One of the objectives is to

gain knowledge regarding how the different subsystems work together as a single Test

Sub-array, i.e. in terms of compatible interfaces, electromagnetic interference and

functionality, et cetera. The main activity of the system is simply to operate the Test

Sub-array. This activity can, in turn, be said to consist of a number of high-level sub

activities that are displayed in the following diagram:

Diagram 4: Function overview

The overall behaviour of these sub activities is displayed through activity diagrams in

the following sections.

Running an experiment is a main part in how to operate the Test Sub-array. It starts

with the Test Sub-array boot-up and ends with the Test Sub-array shutdown. The

Calibrate transmit/receive chain activities are performed occasionally and the

activities Warm Start and Cold Start are functions that cover fault conditions.

Running an experiment

Operate Test Sub-array

Calibrate receiv e chainCalibrate receiv e chain

Receiv eReceiv e

Start an ExperimentStart an Experiment

Calibrate transmit chainCalibrate transmit chain

Cold Start Boot & re-

boot

Cold Start Boot & re-

boot

Test Sub-array shutdownTest Sub-array shutdown

TransmitTransmitTest Sub-array boot-upTest Sub-array boot-up

Exit an ExperimentExit an Experiment

Warm Start Boot and re-

boot

Warm Start Boot and re-

boot



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Running an experiment contains a number of sub activities.

Diagram 5: Running an experiment

The above diagram shows the order of the activities when running an experiment. The

looping between transmit and receive will continue until all the different waveforms

of the experiment have been looped through.

:EISCAT_3D Test Sub-array

:Transmit :Receiv e

:Start an Experiment

Running an experiment -

the whole process

Running an experiment -

the whole process

:Test Sub-array boot-up

:Test Sub-array shutdown

This looping behavior will continue

until all the different waveforms of the

experiment have been looped

through.

:Exit an Experiment



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3.3.1 Test Sub-array boot-up

The activity describes what, and which subsystems, is involved in the process of

booting up the Test Sub-array.

Diagram 6: Test Sub-array boot-up

The Test Sub-array is booted-up through the EROS M&C system, which sends boot-

up commands to the Test Sub-array subsystems. The subsystems (through the control

of the Subsystem Managers) will then perform the necessary boot-up tasks, and

finally send back a message to EROS stating that the subsystem is booted-up.

act [Function] Test Sub-array boot-up [Test Sub-array boot-up]

:First Stage Receiv er Unit:Transmit Unit:Time and Frequency Unit:Pulse and Steering Control

Unit

:EROS

:Test Sub-array

boot-up process

initiated

:Send subsystem

boot-up

commands

:Boot up :Boot up :Boot up :Boot up

:Subsystem

booted-up signal

:Subsystem

booted-up signal

:Subsystem

booted-up signal

:Subsystem

booted-up signal

:Starting the

experiment



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3.3.2 Start an Experiment


starting a Test Sub-array experiment.

Diagram 7: Start an Experiment

An experiment is initiated by EROS. EROS primes the radar function subsystems,

which then performs (through the Subsystem Managers) the system start-up tasks.

The Start an Experiment activity ends after the radar subsystems have sent

"subsystem prepared" signals to EROS. The Time and Frequency Unit is also

continuously distributing the time & synchronization to the PSCU and the FSRU.

:Transmit Unit:First Stage Receiv er Unit:Pulse and Steering Control Unit:Time and Frequency Unit:EROS

:Create and Send

Test Sub-array

start-up signal

:Initialize streaming of

priming commands

:Perform system

start-up tasks

:Receiv e priming

commands

:Receiv e time

:Generate and

distribute time &

synch

Note that this reflects the simplified flow

and hence some tasks and/or flows have

been omitted from this diagram

:Receiv e priming

commands

:Receiv e time

:Receiv e priming

commands

Continuous flow :Send subsystem

prepared signal:Send subsystem

prepared signal:Send subsystem

prepared signal

Activity final

ActivityInitial

:Perform system

start-up tasks

:Perform system

start-up tasks



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3.3.3 Transmit

The activity describes what, and which subsystems, is involved in the Test Sub-array

transmit process.

Diagram 8: Transmit

A Transmit session starts by executing the next line of the event lists provided by the

Subunit Controller. The PSCU calculates new waveforms based on delays and

amplitudes for each channel, generates the proper RF signals that are then up-

converted and analogized before being sent off to the Transmit Unit for amplification

and then to the Antenna Unit which emits the radio frequency waves.

act [Function] Transmit [Transmit]

:Antenna Unit:Pulse and Steering Control Unit :Transmit Unit

:Carry out next line of ev ent list

:Send RF signals

:Calculate new wav eforms,

generate RF signals,

upconv ert & analogize

:Switch to

transmit mode

:Receiv e

generated RF

signals

:Amplify and send

RF signals:Transmit RF

signals

Subsystems have

been primed by

EROSNote that looping occurs until all the scheduled

transmission waveforms have been looped

through. The behavior displayed on this diagram

is simplified and does not explicitly describe for

example transitions to the receive state and

reception of transmission sample.

:Generate & send

T/R control

signals



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3.3.4 Receive

The activity describes what, and which subsystems, is involved in the receive process

of the Test Sub-array.

Diagram 9: Receive

After receiving T/R control signals from the PSCU, the Transmit Unit switches to

receive mode. The echo signals received by the Antenna Unit are then sent to the

FSRU (via the Transmit Unit) for amplification, anti-aliasing and digitizing before

beamforming is carried out. Satellite echoes are removed from the data stream and the

remaining measurement data is then outputted for processing and storage.

act [Function] Receiv e [Receiv e]

:Pulse and Steering

Control Unit

:First Stage Receiv er Unit:Transmit Unit:Antenna Unit

:Receiv e and

transfer RF

signals

:Receiv e

generated RF

signals

:Amplify low

signal

:Switch to receiv e

mode

:Perform anti-

aliasing

:Perform

beamforming

:Transfer beams

:Digitize RF

signals

:Process

receiv ed beams

:Satellite echo

remov al from data

stream

ActivityInitial

:Computing System

ActivityFinal

:Generate & send

T/R control

signals



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3.3.5 Exit an Experiment

The activity describes what, and which subsystems, is involved in exiting an

experiment.

Diagram 10: Exit an Experiment

After receiving an exit signal from EROS, the subsystems perform (through the

Subsystem Managers) the different tasks needed to exit the active experiment mode.

Finally, the Subsystem Managers of the subsystems send messages to EROS stating

the experiment exit process has been completed.

:Transmit Unit:First Stage Receiv er

Unit

:Pulse and Steering

Control Unit

:EROS

:Create and Send

Test Sub-array

exit signal

:Send subsystem

exited signal

:Send subsystem

exited signal:Send subsystem

exited signal

:Perform system

exit tasks

:Perform system

exit tasks

:Perform system

exit tasks

ActivityFinal



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3.3.6 Test Sub-array shutdown

The activity describes what, and which subsystems, is involved in shutting down the

Test Sub-array.

Diagram 12: Test Sub-array shutdown

The shutdown process is initialized by EROS which then commands the Subsystem

Managers (except for the Time and Frequency Unit where this communication is

made directly to the system) of the subsystems to perform the procedures necessary to

shut down the subsystem.

:First Stage Receiv er Unit:Transmit Unit:Time and Frequency Unit:Pulse and Steering Control

Unit

:EROS

:Test Sub-array

shut-down

process initiated

:Subsystem

Shutdown

:Subsystem

Shutdown

:Subsystem

Shutdown

:Subsystem

Shutdown

:Send subsystem

shut-down

commands



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3.3.7 Calibrate transmit chain


calibrating the transmit chain of the Test Sub-array.

Diagram 11: Calibrate transmit chain

The process of calibrating the transmit chain runs through the system as it would

during normal transmit mode except the Transmit Unit sends the non-amplified

calibration signals to the Antenna Calibration Tower.

UserComputing system?:Antenna Calibration Tower:Pulse and Steering Control Unit :Transmit Unit

:Carry out next line of

ev ent list

:Send RF signals

:Receiv e

calibration signal

:Receiv e

generated RF

signals

:Insert new

settings

:Sav e and

process

calibration data

:Switch to

transmit mode

:Apply new settings

The settings are applied

to the exciter, but how

this is done is TBD.

ActivityInitial

:Generate & send

T/R control

signals

:Calculate new wav eforms,

generate RF signals,

upconv ert & analogize



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3.3.8 Calibrate receive chain


calibrating the receive chain of the Test Sub-array.

Diagram 13: Calibrate receive chain

The process of calibrating the receive chain runs through the system as it would

during normal receive mode. except the Antenna Calibration Tower starts the process

through sending out calibration Tx signals. After going through the different

processes of the receiver (no beamforming is performed), the calibration signals are

processed and offsets are calculated. The new settings are then manually inserted into

the First Stage Beamformer.

act [Function] Calibrate receiv e chain [Calibrate receiv e chain]

:User:Computing System:First Stage Receiv er

Unit

:Antenna Calibration Tower

:Prepare

calibration tx

:Amplify low

signal

:Perform anti-

aliasing

:Digitize RF

signals

:Calculate offsets

etc

:Process

calibration

signals

Note that this reflects the

simplified flow and hence some

tasks and/or flows have been

omitted from this diagram

:Insert new

settings into the

Beamformer

:Receiv e

calibration

signals

:Implement new

settings

ActivityInitial

ActivityFinal



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3.3.9 Warm Start Boot and re-boot


booting and re-booting the Test Sub-array during a “warm start” where SubMan is

still running and can respect an exit command from EROS.

Diagram 14: Warm Start Boot and re-boot

EROS sends an exit command to the SubMan of the Subsystem Manager. If SubMan

is responding it exits, following which the Subsystem Manager computer restarts

SubMan. In the case SubMan is not responding to the EROS exit command, EROS

terminates the process through a kill commands which shuts down SubMan, which in

turns leads to SubMan restarting.

act [Function] Warm Start Boot and re-boot [Warm Start Boot and re-boot]

Computer SubMan:EROS

Send exit

command

SubMan exitsComputer

restarts SubMan

is SubMan responding to exit command?

Terminate

process through

kill command

Shut down

SubManSubMan restarts

no

yes



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3.3.10 Cold Start Boot & re-boot


booting and re-booting the Test Sub-array during a "cold start” following a mains

power failure.

Diagram 15: Cold Start Boot & re-boot after power has returned

After the external power switch has been closed again after being open, the computer

of the different Subsystem Managers boot up automatically. The SubMan starts

running and then closes the subsystem internal power switch, after which the

subsystem radar hardware is powered up.

act [Function] Cold Start Boot & re-boot [Cold Start Boot & re-boot after power has returned]

:EROS Power switch Subsystem:Subsystem Manager General

:Close external

power switch

:Automatic

computer boot-up

:Run SubMan

:Power up

This may or may not

occur.

:Close power

switch

If the SubMan's default behavior is not to

boot the hardware after power failure then

the hardware needs to be booted explicitly

by an EROS command



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3.4 Overall design decisions

Due to its nature, some of the subsystems of the Test Sub-array will have to be RF

shielded in order to protect them from the radiated fields in the array, as well as the

internally generated RF noise (e.g. clock signals). The following overall design

decisions have been taken to address this:

The Test Sub-array will contain two RF shielded instrument containers – one for

the Transmit System and one housing the First Stage Receiver Unit, the Pulse and

Steering Control Unit, and the Time and Frequency Unit. This solution will shield

the sensitive subsystems by preventing direct electromagnetic interference to these

from the Transmit Unit.

The design of the internal electronics will also include protection from internally

generated electromagnetic noise within the Test Sub-array



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4 System architectural design

This chapter describes the technical system that enables the behaviour described in

section Behavioural design. The Test Sub-array consists of a number of subsystems

and these components are defined and described in this chapter.

This chapter displays a number of structural diagrams of the Test Sub-array and its

subsystems. See section 6.1 Description of Diagrams for more information.

4.1 System components

The following diagram displays an overview of the technical subsystems of the Test

Sub-array. The arrowed lines represent the categories of interactions that have been

identified between the subsystems. A category (e.g. status, notifications and RF) can

comprise a number of different signals or information flows. The external systems

that the Test Sub-array are interacting with are represented by the ports on the edge of

the diagram. For a more comprehensive view this diagram can be read together with

the "Operational Domain" diagram. Note that the diagram provides a simplified view,

thus all parts and components of the subsystems may not be visualized.

The Test Sub-array is a phased-array antenna radar system containing 91 crossed

dipole antenna elements, a beamformer, a receiver, a transmitter and other subsystems

for control, time-keeping et cetera.

Diagram 16: Test Sub-array Technical systems High level Overview

The diagram above displays a high level overview of the technical subsystems of the

Test Sub-array. It conveys not only which components interact with each other, but

also the kind of information that is exchanged between the components.

ibd [block] EISCAT_3D Test Sub-array [Test Sub-array Technical systems High lev el Ov erv iew]

pscu / d: Pulse and Steering Control Unit

tu / c: Transmit Unit

fsru / e: First Stage Receiv er Unit

tfu / b: Time and Frequency Unitau / a: Antenna Unit

Tx

Rx

Rx, Tx

signals EROS control, Status inquiry Notification, Status

EROS control,

Status inquiry

Notification,

Status

Tx

EROS control,

Status inquiry

Notification,

Status

T/R Control

Measurement data

Status inquiry,

EROS control

Notification,

Status

Time,

Synchronization



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4.1.1 General components

The section describes general components found in the EISCAT_3D Test Sub-array.

4.1.1.1 Subsystem Manager

EISCAT_3D Test Sub-array contains several different subsystem managers which are

named "Subsystem Manager Xyz". Each different subsystem manager has a specific

set of behaviors and functionality that is described in its corresponding section. The

description, behavior and functionality below is general for all subsystem managers

and is defined by the Subsystem Manager. Note that the Subsystem Manager is not a

real physical component itself but just a placeholder for a general description. A

Subsystem Manager communicates through “SubMan”.

The Subsystem Manager provides a network-accessible interface between its

associated subsystem (a block of hardware with basic software and firmware that

implements a set of specific radar functionality) and EROS. The Subsystem Manager

implements SubMan that EROS communicates with in order to control and monitor

the subsystem. This is enabled by the Subsystem Manager providing a TCP socket

listener at a fixed (but configurable) network address.

SubMan receives EROS control commands that specify what the subsystem is

expected to do and SubMan also receives Status inquiry commands that specify

specific information that EROS needs SubMan to return in the form of a Status

message. SubMan also issues Notifications to EROS, without being explicitly

prompted by EROS, if it detects an anomaly of some kind, e.g. if some predefined

conditions are met (e.g. temperature exceeding a set maximum value).

4.1.1.2 Subunit Controller

The Subunit Controller supplements the overall architecture with binary packets

containing waveforms and event lists needed for the PSCU. Event lists include time

stamps, waveform start time, and state changes for T&R switch and extra outputs.



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4.1.2 Pulse and Steering Control Unit

The Test Sub-array subsystems are able to operate together as intended through

different control pulses or triggers that determine when the different subsystems begin

their different tasks. The Pulse and Steering Control Unit, together with external

system Subunit Controller (see section Subunit Controller for more information),

provides this control capability in addition to generating and distributing the actual RF

signals.

Diagram 17: Pulse and Steering Control Unit

The diagram above displays the logical implementation of the PSCU components.

Actual implementation is up to the vendor. The main functions of the PSCU is to

produce and send control commands to the Transmit Unit T/R Switch, calculate and

send waveforms for each channel that take given delays and amplitudes into

consideration as well.

Also displayed on the diagram is the Subunit Controller, which is not part of the

procurement object PSCU (hence dashed border) but is closely connected to it and

displayed for comprehension purposes.

p10: Mechanical and

Electrical Interface

p11:

GPIO

p08: RF

[192]

p09: Slow

Ethernet

ibd [block] Pulse and Steering Control Unit [Pulse and Steering Control Unit]

p10: Mechanical and


p11:

GPIO

p08: RF

[192]

p09: Slow

Ethernet

Port1: TCP

Port2: UDP

sm: Subsystem Manager PSCU[1]

Port1: TCP

Port2: UDP

e: Exciter[1..*]

ps: Power Supply PSCU

[1..*]

wrs: WR Slav e PSCU

[1]

suc: Subunit

Controller

there will be 182 (91x2) RF signals and 10 extra

channels for calibration purposes. The number

of physical exciter units is up to the vendor.

1 output for T/R control and 7 extra

outputs for oscillators et cetera.

fc: 233.3 MHzTime,

Synchronization

T/R Control,

General SignalsStatus, Notification External Control,

Status inquiry

Event l ists,

Waveforms

230 V

Time,

Synchronization



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4.1.2.1 Subsystem

Exciter

The Exciter generates RF signals that will be up converted and analogized before

distributed to the Transmit Unit for amplification. The signals include all information

about the frequency, phase and polarization. The Exciter also includes a T/R control

function which generates and sends control signals to the Transmit Unit T/R Switch.

The Exciter is time synchronized through the WR system.

Power Supply PSCU

The Power Supply PSCU is supplied 230 V (AC) from the site mains power.

Subsystem Manager PSCU

The Subsystem Manager PSCU is specific for the Pulse and Steering Control Unit.

The Subsystem Manager provides slow control input, mainly during system start-up,

and system status monitoring. The specific functionality of the Subsystem Manager

PSCU includes the calculation of new waveforms based on given delay and amplitude

values for each channel and implementing a buffer for event lists provided by the

Subunit Controller.

WR Slave PSCU

The WR Slave extracts the time and synchronization from the 1 Gb Ethernet network

and provides it to the subsystem. The WR Slave consists of specialized WR node

cards.

4.1.2.2 Informationflows

Name Information Producer Interface Consumer Interface

c070 Waveforms,

Event lists

suc N/A sm Port2:UDP

c071 Notification,

Status

sm Port1:TCP suc N/A

c071 External

Control, Status

inquiry

suc N/A sm Port1:TCP

c13 fc: 233.3 MHz

e N/A Pulse and

Steering

Control Unit

p08:RF

c16 230 V

Pulse and

Steering

Control Unit

p10:Mechani

cal and

Electrical

Interface

ps N/A



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c704 T/R Control,

General Signals

e N/A Pulse and

Steering

Control Unit

p11:GPIO

c705 Time,

Synchronizatio

n

Pulse and

Steering

Control Unit

p09:Slow

Ethernet

wrs N/A

4.1.2.3 Interfaces

Name Type Information

p08 RF The radio frequency signals from the Exciter to the

Transmit Unit are sent over this interface.

p09 Slow Ethernet The communication with EROS is sent over this

interface.

p10 Mechanical and

Electrical

Interface

This interface provides the Pulse and Steering Control

Unit with the required current and voltage. It also

includes the physical interface.

p11 GPIO The T/R control signals and General Signals to the

Transmit Unit are sent over this interface.

4.1.3 Network Components

Network Components are TBD.



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4.1.4 Antenna Unit

The Antenna Unit includes the subsystems Antenna Array, Array Structure and

Ground Plane. Note that the unit also includes mechanical attachment interfaces as

well as cables, connectors and cable trays (or similar).

Diagram 18: Antenna Unit

The diagram displays the Antenna Unit and all of its parts. As shown on the diagram,

the Antenna Unit also includes an Array Structure which the Antenna Elements are

mounted on, and a meshed ground plane which is attached to the Array Structure.

Further, the Antenna Unit also includes the cables and connectors that connects the

Antenna Unit to the Transmit Unit. The antenna cables are routed to a point near the

center of the Test Sub-array just below the Array Structure.

4.1.4.1 Subsystem

Antenna Array

The Antenna Array consists of the Antenna Elements.

The purpose of the Antenna Array of the Test Sub-array is to transduce the RF signals

to electromagnetic waves (or vice versa if in receive mode). The hexagonally shaped

array will consist of 91 crossed-dipole Antenna Elements, hence adding up to a total

number of 182 dipoles to be sampled. The dipoles are tilted back towards the ground

plane (inverted v-shape) to enable good steering without excessive changes in

polarization ratio or antenna terminal impedance.

The antenna elements of the Antenna Array are mounted on a support structure

described in section Array Structure.

p98:

Mechanical

Attachment

Interface

p97:

RF

ibd [block] Antenna Unit [Antenna Unit]

p98:

Mechanical

Attachment

Interface

p97:

RF

p94:

Mechanical

Attachment

Interface

: Array Structure

p94:

Mechanical

Attachment

Interface

: Ground Plane

p01: RF

: Antenna Array

p01: RF

ae: Antenna Element

[91]



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Antenna Unit Cables and Connectors

The Antenna Unit Cables and Connectors are all the cables and connectors used to

connect the antennas to the Transmit Unit.

Array Structure

The Array Structure is a metallic support structure holding all the Antenna Elements.

The Array Structure is approximately 3 meters high.

Ground Plane

The Ground Plane is a flat, or nearly flat, horizontal conducting surface that serves as

part of an antenna, to reflect the radio waves from the other antenna elements.

4.1.4.2 Interfaces


p97 RF Interface for radio frequency signals between the

Antenna Unit and the Transmit Unit.

p98 Mechanical

Attachment

Interface

Interface between Array Structure and foundation.



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4.1.5 Time and Frequency Unit

White Rabbit (WR) is a protocol developed to synchronize nodes in a packet-based

network with sub-nanosecond accuracy. The WR network consists of a set of different

so called boundary and ordinary clocks in addition to a grand master clock. WR

provides the link delay information and clock syntonization (frequency transfer) over

the physical layer with Synchronous Ethernet (SyncE). In the SyncE scheme, the WR

master (using the reference clock) encodes the outgoing data stream. The same clock

is retrieved on the other side of the physical link, and the retrieved frequency can be

further distributed. The recovered clock is also always looped back to the WR Master

(via the WR Switch) for clock phase alignment with the master.

The reference clock uses a GPS clock as the time and frequency standard (TBD). The

WR Master functions as the grand master clock and is the source of time and

frequency for the other WR clocks in the network. The WR Switch is a boundary

clock that synchronizes and syntonizes to the master clock. The reference signals

retrieved by the switch are redistributed to syntonize other slave clocks connected to

its ports. The WR Slave is an ordinary clock which retrieves the reference signals sent

over a link by the WR Master (via the WR Switch) and uses the recovered reference

clock (after a phase adjustment) for all its operations. The subsystems that are time

dependent retrieve the time and synchronization to ensure that the system stays

synchronized.

Diagram 19: Time and Frequency Unit

EROS provides (over the Slow Ethernet) the Time and Frequency Unit with slow

control input, mainly during system start-up, and system status monitoring, see

section EROS for more information.

Note that this subsystem may be subject to change.

p17:

Mechanical

and

Electrical

Interfacep47: Slow Ethernet

ibd [block] Time and Frequency Unit [Time and Frequency Unit]

p17:

Mechanical

and

Electrical

Interfacep47: Slow Ethernet

wrm: WR Masterrc: Reference

clock

wrsw: WR Switch

Status and EROS

control sent using

SNMP protocol

230 V

230

V

EROS

control

Status

Time,

Synchronization



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4.1.5.1 Subsystem

Reference clock

The reference clock uses a GPS clock as the time and frequency standard, and

provides a reference phase for the transmitted and received signals.

WR Master

The WR Master uses a traceable clock to encode data over SyncE.

WR Switch

The WR Switch then distributes the clock signal over a 1 Gbit/s Ethernet network (the

same network will also be used for inputs and outputs of the EROS).



c1847 Status

wrm p18:Slow

Ethernet

Time and

Frequency

Unit

p47:Slow

Ethernet

c1847 EROS control

Time and

Frequency

Unit

p47:Slow

Ethernet

wrm p18:Slow

Ethernet

c28 230 V

Time and

Frequency

Unit

p17:Mechani

cal and

Electrical

Interface

rc p45:Mechani

cal and

Electrical

Interface

c32 230 V

Time and

Frequency

Unit

p17:Mechani

cal and

Electrical

Interface

wrm p26:Mechani

cal and

Electrical

Interface

c44 Time,

Synchronizatio

n

wrsw p21:Slow

Ethernet

Time and

Frequency

Unit

p47:Slow

Ethernet

4.1.5.3 Interfaces


p17 Mechanical and

Electrical

Interface

Interface providing the Time and Frequency Unit with

power. Ihe interface connects to the power supply.

p47 Slow Ethernet WR time



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4.1.6 Cables and Connectors

The Test Sub-array also includes the Cables and Connectors necessary to connect the

different subsystems. The system component includes:

the technical solution to send the Radar control signals throughout the system

the technical solution to send the Interlock control signals throughout the system

Note that the cables and connectors for the Antenna Elements are included in the

Antenna Unit as described in section Antenna Unit.

4.1.7 Transmit unit container

The Transmit Unit Container is container containing equipment for the transmit unit.

Diagram 20: Transmit unit container

The diagram shows the Transmit Unit Container and its external interfaces. The

container contains the Transmit Unit.

4.1.7.1 Interfaces


1 Gb Slow Ethernet 1 Gb Ethernet interface.

3-phase Mechanical and

Electrical

Interface

400 volts interface.

RF from

exciter(s)

RF From Pulse and Steering Control.

Rx and

Tx signals

RF Interface for Tx and Tx signals to the First Stage

Receive Unit.

RF from exciter

(s): RF

T/R Control:

GPIO

1 Gb: Slow

Ethernet

Rx and Tx

signals: RF

3-phase:

Mechanical and


Tx and Rx: RF

ibd [block] Transmit unit container [Transmit unit container]

RF from exciter

(s): RF

T/R Control:

GPIO

1 Gb: Slow

Ethernet

Rx and Tx

signals: RF

3-phase:

Mechanical and


Tx and Rx: RFtu: Transmit Unit



2016-09-08

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T/R

Control

GPIO Interface for control signals from the Pulse and

Steering Control Unit.

Tx and

Rx

RF From Antenna Unit

4.1.8 Climate monitoring equipment

This unit will monitor the temperature and humidity inside the Instrument Container

described in section Instrument Containers, and will send this information to the

container Subsystem Manager.

4.1.8.1 Interfaces


p49 TBD

p50 TBD

4.1.9 TU Power Supply Container

The TU Power Supply Container contains the power supply for the Transmit unit.

4.1.10 Subsystem Manager Container

The Subsystem Manager Container is specific for the Instrument Container. The

specific functionality is to be defined.

4.1.10.1 Interfaces


p104 Mechanical and

Electrical

Interface

p65 TCP First Stage Receiver Unit

p68 TBD First Stage Receiver Unit

p88 Listening TCP

socket

4.1.11 Transmit Unit

The main purpose of the Transmit Unit is to produce high-power RF pulses that are

radiated into space by the Antenna Elements. The subsystem consists of power

amplifiers, T/R switches, power supply units and a Subsystem Manager (see EROS in

section Interactions with surrounding systems and section Subsystem Manager for

more information).

The power amplifiers are used to amplify the RF waveform for transmission and the

SSPA is a power amplifier that supports long pulses and high duty cycle waveforms.

The T/R Switch shifts the radar system from transmit mode (when the Transmit Unit

needs to be connected to the Antenna Unit and disconnected from the receiver) to



2016-09-08

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receive mode (when the T/R Switch will connect the incoming RF signals to the

receiver) or vice versa.

The following diagram displays the Transmit Unit, its parts, and its external

interfaces.

Diagram 21: Transmit Unit

The diagram displays all external interfaces. When the subsystem is in transmitting

mode, the RF signal from the Pulse and Steering Control Unit is received by the

SSPA unit. After amplification the RF signal is sent to the Antenna Elements via the

T/R Switch and a, much attenuated, copy of the RF signal is also sent to the Front End

of the First Stage Receiver Unit. During receive mode the incoming RF signal is

received by the First Stage Receiver Unit via the T/R Switch.

4.1.11.1 Subsystem

SSPA Unit

The SSPA Unit contains the T/R Switch, and is installed and operated inside the

container below the support structure for the antenna sub-array. The SSPA also

contains supervisor functions for output power, excess reflected power, excess

temperature, and other critical parameters.

p32:

RF

p28: Slow Ethernetp29: Mechanical and Electrical

Interface

p31:

RF

p30:

GPIO

p27:

RF

p107

ibd [block] Transmit Unit [Transmit Unit]

p32:

RF

p28: Slow Ethernetp29: Mechanical and Electrical

Interface

p31:

RF

p30:

GPIO

p27:

RF

p107

p40

p41

p42sm tu: Subsystem

Manager TU

p40

p41

p42

p38

p43p44

ps: Power supply TU

p38

p43p44

p33

p36

p37

p99

su: SSPA Unit

p33

p36

p37

p99

s1: SSPA[182] trs: T/R Switch[182]

fc: 233.3 MHz

T/R

Control

400 VStatus,

Notification

Status inquiry,

EROS control

fc: 233.3 MHz

fc: 233.3 MHz

Interlock control

Status

SubMan control

182 182

182 182

182

182



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c10799 Interlock

control

Transmit

Unit

p107 su p99:Interlock

control

c35 fc: 233.3 MHz

Transmit

Unit

p27:RF su p36:TBD

c37 Notification,

Status

sm tu p41:Slow

Ethernet

Transmit

Unit

p28:Slow

Ethernet

c37 Status inquiry,

EROS control

Transmit

Unit

p28:Slow

Ethernet

sm tu p41:Slow

Ethernet

c38 400 V

Transmit

Unit

p29:Mechani

cal and

Electrical

Interface

ps p43:Mechani

cal and

Electrical

Interface

c42 fc: 233.3 MHz

su p35:TBD Transmit

Unit

p31:RF

c43 fc: 233.3 MHz

Transmit

Unit

p32:RF su p34:TBD

c43 fc: 233.3 MHz

su p34:TBD Transmit

Unit

p32:RF

4.1.11.3 Interfaces


p107 TBD Interface for Interlock Control Signals. TBD.

p27 RF Interface for incoming radio frequency signals from

the Exciter of the Pulse and Steering Control Unit.

p28 Slow Ethernet Interface for information exchange with M&C system

external to the Test Sub-array.

p29 Mechanical and


400 V, 3 phase

p30 GPIO The interface block handles T/R Control and is TBD.


Transmit Unit and the First Stage Receiver Unit.


Antenna Unit and the Transmit Unit.



2016-09-08

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4.1.12 Instrument Container

Some of the sensitive systems and equipment are placed in an instrument container to

aid with temperature and humidity control and RF shielding (to protect the internal

electronics). Environmental and power monitoring equipment will also be placed in

the container to enable remote monitoring and control. The electrical systems located

inside the container will also include remote control capabilities to for example allow

powering down failed or interfering units. Maintenance and cost are two major factors

that will affect the design of the internal layout of the container. The Transmit Unit is

placed in its own container in order to meet the requirements described in section 3.4

Overall design decisions. To monitor the state of the Instrument Container, it will

house its own Subsystem Manager.

The following diagram displays the Instrument Container and the subsystems located

inside of it. The rectangles representing the technical subsystems are dashed to reflect

that they are not parts of the Instrument Container.

Diagram 22: The Instrument Container including the systems and components it is housing

The above diagram displays the instrument container and the subsystems located

inside of it. The rectangles representing the technical subsystems are dashed to reflect

that they are not parts of the instrument container.

4.1.12.1 Interfaces


p101 RF The RF signals to, and from, the Transmit Unit and

sent over this interface.

p102 GPIO The control signals to the Transmit Unit are sent over

this interface.

p103 Slow Ethernet The time and synchronization from the Time and

Frequency Unit as well as the EROS communication

is sent over this interface.

p105: Fast

Ethernet

p103: Slow Ethernet

p106: TBD

p102: GPIO

p51: Mechanical

Attachment Interface

p53: Mechanical and


p101: RF

ibd [block] Instrument Container [The Instrument Container including the systems and components it is housing]

p105: Fast

Ethernet

p103: Slow Ethernet

p106: TBD

p102: GPIO

p51: Mechanical

Attachment Interface

p53: Mechanical and


p101: RF

p07p03

p04p05

fsru: First Stage Receiv er Unit

p07p03

p04p05

p08[192]

p11

p09p10

pscu: Pulse and Steering Control Unit

p08[192]

p11

p09p10

p47

p17

tfu: Time and Frequency Unit

p47

p17

p68

p65 p88 p104

sm: Subsystem Manager Container

p68

p65 p88 p104

: Computing System



2016-09-08

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p105 Fast Ethernet The measurement data from the computing system is

sent over this interface.

p106 TBD This interface is for the RF (Tx and Rx) signals from

the Transmit Unit.

p51 Mechanical

Attachment

Interface

This interface attaches the different subsystems within

the Instrument Container.

p53 Mechanical and

Electrical

Interface

The mechanical and electrical interface provides the

component with the required voltage and current.

4.1.13 First Stage Receiver Unit

The First Stage Receiver Unit consists of the following main subsystems: the receiver

Front End, Analogue-to-Digital converter unit, and the First Stage Beamformer. The

receiver Front End receives the wide-band, noisy signals from all the individual

antenna elements and conditions them so that they are suitable for sampling and

further digital processing. The conditioning includes frequency-band limitation by an

Anti-aliasing Filter and amplification with a Low Noise Amplifier. The conditioned

signals are then sampled with analogue-to-digital converters (ADC) and fed to the

First Stage Beamformer. The First Stage Beamformer performs the first few stages of

the digital signal processing that ultimately gives the antenna array its characteristic

directional sensitivity (“forms the antenna beams”).

Diagram 23: First Stage Receiver Unit

As shown on the diagram, the First Stage Receiver Unit consists of a Front End

(containing filters and power supply), a First Stage Beamformer, a Multichannel ADC

(and its power supply), a WR Slave, and a Subsystem Manager. The Subsystem

p79: TBD

p07: Fast

Ethernet

p05:

Mechanical

and

Electrical

Interface

p04:

Slow

Ethernet

p03

ibd [block] First Stage Receiv er Unit [First Stage Receiv er Unit ]

p79: TBD

p07: Fast

Ethernet

p05:

Mechanical

and

Electrical

Interface

p04:

Slow

Ethernet

p03p61

p63

p64p62

p70

p77

fsb / k: First Stage Beamformer

p61p63

p64p62

p70

p77

p57

p59

p58

p69

fe / h: Front End

p57

p59

p58

p69

aaf: Anti-aliasing

filter

lna: LNA

ps: Power Supply BF

LNA: Power

Supply LNA

p80

p81

adc / j : Multi channel ADC 14 or

16 bit

p80

p81

p85p91

ADC / n: Power Supply

FSRU

p85p91p19

WRS / m: WR Slav e

FSRU

p19

p65p66

p67p90

p88

p68

smfsru: Subsystem Manager FSRU

p65p66

p67p90

p88

p68

TBD V

TBD V

TBD V

Control

Notification, Status

Time, Synchronization

fc: 233.3 MHz

TBD V

fc: 233.3

MHzMeasurement data

14 or 16 bit data

Time,

Synchronization

StatusSubMan control

SubMan

control

StatusPower on/off

Status inquiry,

EROS control



2016-09-08

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Manager implements SubMan that EROS communicates with in order to control and

monitor the subsystem. Note the ADC has been placed between the Front End and the

First Stage Beamformer in the diagram but it is up to the designer of the First Stage

Receiver Unit if placed inside the Front End or inside of the First Stage Beamformer.

4.1.13.1 Subsystem

First Stage Beamformer

The First Stage Beamformer is used for signal processing and provides discrete spatial

filtering across the aperture of the radar array. The system is responsible for sampling

the signals from the Antenna Elements and filtering and forming multiple receive

beams. Beamforming can, as previously mentioned, reduce the interference signals

(external electromagnetic interference) but only if the receiver chain associated with

each antenna element remains fairly linear.

The First Stage Beamformer introduces carefully calculated, antenna element specific

time delays to each of the digitized signals coming from the elements; sums the

signals coherently, that is, adds them in the voltage domain rather than in the power

domain; and performs the so called IQ-detection which converts a real-valued signal

into a complex-valued signal that represent only one side of the original two-sided

spectrum. In IQ-detection, the data flow rate, typically expressed in units of a million

samples per second (MS/s), is converted from type “NN MS/s real” to “NN/2 MS/s

complex”. Depending on the used IQ-detection method, the First Stage Beamformer

may also shift the signal to near the zero frequency. In addition, the First Stage

Beamformer may further reduce the bandwidth of the signal and the data flow rate in

a process called decimation.

The IQ-detection processing is required to produce a complex-valued sample stream

that represents information coming from a particular direction in the sky, that is, the

stream corresponds to a particular beam. It is required that up to 10 beams, in

different pointing directions, are produced simultaneously. The Beamformer

accomplishes this by using the same data samples from the Front End as above, but by

using up-to nine other sets of the element-specific time delays and repeating the

calculations. Taking into account the available two antenna polarization, a data stream

corresponding to up to 20 full bandwidth beams (in 10 directions) will be produced

out of the First Stage Beamformer.

Front End

The band-pass filtering done in the Front End has two main functions. First, it

ensures that the signal bandwidth in front of the ADC is compatible with the sampling

frequency in terms of the Nyquist criterion for bandpass sampling. The criterion states

that the periodic spectral replicas of the analog band, by the sampling frequency, must

not overlap. The other task is to prevent unwanted, often very strong, neighboring

electromagnetic signals, the out-of-band interference, of entering the digital

processing chain. This protection task of the filter can only succeed if the low noise

amplifier in front of the filter can tolerate all the extra load caused by the out-of-band

interference without losing its linearity, so that no spurious signals are generated

directly into the measurement band.



2016-09-08

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Multi channel ADC 14 or 16 bit

The ADC digitizes the signals from the Front End and outputs them to the First Stage

Beamformer.

Power Supply FSRU

The power supply TBD.

Subsystem Manager FSRU

The Subsystem Manager FSRU is specific for the First Stage Receiver Unit. The

specific functionality is to be defined.

WR Slave FSRU

The WR Slave extracts the time and synchronization from the 1 Gb Ethernet network

and provides it to the subsystem. The WR Slave consists of specialized WR node

cards.



c04c65 Status inquiry,

EROS control

First Stage

Receiver

Unit

p04:Slow

Ethernet

smfsru p65:TCP

c04c88 Notification,

Status

smfsru p88:Listening

TCP socket

First Stage

Receiver

Unit

p04:Slow

Ethernet

c10 TBD V

First Stage

Receiver

Unit

p05:Mechani

cal and

Electrical

Interface

fsb p70:Mechani

cal and

Electrical

Interface

c2 fc: 233.3 MHz

First Stage

Receiver

Unit

p03:TBD fe p58:TBD

c51 Control

First Stage

Receiver

Unit

p04:Slow

Ethernet

fsb p77:TBD

c69p66 TBD V

First Stage

Receiver

Unit

p79:TBD smfsru p66:Mechani

cal and

Electrical

Interface



2016-09-08

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4.1.13.3 Interfaces


p03 TBD Interface for receiving RF signals from the Transmit

Unit.

p04 Slow Ethernet Interface for exchanging information with EROS and

receiving WR Time and Synchronization.

p05 Mechanical and

Electrical

Interface

Interface with the Mains Power.

p07 Fast Ethernet Specification TBD.

p79 TBD External Interface to Remotely Controlled Power

Switch. Power to the Subsystem Manager.

4.2 Concept of execution

TBD. This section will display any necessary state machines and/or sequence diagram

when the information needed has been gained.

4.3 Interface design

This section will list the different information items that have been identified (see

section System components) or proposed for each Information item category.

4.3.1 Data model

The table below describes the information exchanged between the interfaces in the

system. In the table symbols △and ◆ are used to define generalisation respectively

aggregation. Generalisation can be interpreted as "a sort of" and aggregation as "part

of".

Element IK Description

EROS control

External control commands are sent from a control

system external to the Test Sub-array (e.g. EROS) to the

Subsystem Manager in order to enable remote controlling

of for example system start-up and shut-down. After

receiving an external control command, the subsystem is

expected to behave in some predefined manner.

Measurement data

~67 Gb/s stream of measurement data containing the

resulting beams (2x10 beams) from the signal processing

of the First Stage Beamformer.

Notification

Notification signals are sent from the Subsystem Manager

to a control system external to the Test Sub-array. They

enable a more thorough monitoring of the health and

status of the Test Sub-array. In the event of an anomaly



2016-09-08

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being detected, the Subsystem Manager will issue a

notification describing what has happened to the control

system.

RF Radio Frequency signal

Rx

△RF

Received signal.

Status

The Subsystem Manager shall respond to a Status Inquiry

with a Status message containing the information

requested in the Status Inquiry.

Status inquiry

Status inquiries are sent from the external control system

to the Subsystem Managers and enable the overall

monitoring of the health and status of the Test Sub-array

subsystems. The Subsystem Manager receives the status

inquiry command, retrieves the requested information and

then returns it back to EROS through status signals.

Time,

Synchronization

Time signal containing frequency and synchronization

(e.g. pulse-per-second) references used for timekeeping

and time measurement.

Tx

△RF

Transmitted signal.

Tx signals

△RF

Samples of transmitted signal.

4.3.2 EROS/Subsystem Manager Message Protocol

EROS communicates with SubMan via a single, configurable network address (IP

address and port number) by using the Tcl wire protocol, see

https://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/comm/comm_

wire.html

The general structure of a command from EROS to SubMan is a Unicode UFT-8

encoded string of space-separated words – consisting of command name followed by

flags, options, and command arguments:

command = name parameter parameter …

The command structure is compatible with the standard C library routine getopt. The

Tcl wire protocol embeds the command string into a communication frame,

terminating in the line feed character (UNIX: “\n”). The entire message string

normally has the following structure:

message = { instruction transaction_id { command } } LF

https://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/comm/comm_wire.html





2016-09-08

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The Tcl wire protocol supports three different instruction words, and SubMan

supports at least two of them: send and async.

instruction = send | async

Send means that SubMan performs the required task and then sends an explicit reply

to the involved EROS client (which is blocked during the execution of the task). Note

that everything described in this section must be carried out according to the Tcl wire

protocol.

Async means that SubMan performs the required task but it will not send a reply of

any kind and the involved EROS client will not be blocked and is proceeding

immediately after sending its command to SubMan. The async command may for

example be used to launch a long-living action in the subsystem.



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5 Requirements Allocation

Requirements and requirement allocation are found in the Technical Specification for

each subsystem.



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6 Notes

The diagrams in this document are created using SysML modelling language. The

diagram presents a view of the system or subsystem and may not display all of the

information that is available in the underlying system or subsystem model.

6.1 Description of Diagrams

In this document both structural and behavioural diagrams are included.

In structural diagrams, the different subsystems and components are represented by

rectangles that each displays the type of system, the name of that instance, as well as

any subsystems (parts) that are of contextual importance. A diagram can also display

the interactions between the systems and these interactions are represented by lines.

The lines can be arrowed which displays the direction of the flow (that composes the

interaction, e.g. flows of information, matter, etc.) and the type of flow (for example

“control” if control signals are sent between some systems) may also be displayed.

The diagram below exemplifies a number of different items that can appear on a

structural diagram, as described in the previous paragraph. External interfaces, if

displayed, are represented by small squares on the diagram edges of the subsystems.

Activity diagrams are used to specify behaviours, with a focus on the flow of control

and the transformation of inputs into outputs through a sequence of actions. Activity

partitions (visualized as the vertical ”swimlanes” on the diagrams) enable you to

allocate system behaviours to system structures (for example subsystems and users),

i.e. displaying who will do what in which order.

The arrows represent the flow between the different actions (“subactivities” or tasks)

of the activity. On the activity diagrams in this SSDD, the flows simply indicate

which action is currently enabled during the execution of the activity. Activity

diagrams express the order in which actions are performed as well as which structure

performs each action, but they do not offer any mechanism to express which structure

invokes each action.

In summary, the activity diagram can be said to provide a dynamic view of the system

that displays sequences of system tasks or activities that will be carried out, as well as

the general flow between these activities over time. [SysML]



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Diagram 24: Interpretation of structural diagrams

eiscat 3d (test sub-array) system and subsystem …...2016/09/08 · this system and subsystem...

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