FM/DAB/DVB-T Multiband Multistatic Passive Radar System...

M. Edrich

Hensoldt Sensors GmbH / ex Airbus DS EBS GmbH

FM/DAB/DVB-T Multiband Multistatic Passive Radar

System – Design Considerations and Lessons Learnt

This document and its content is the property of Airbus DS Electronics and Border Security GmbH. It shall not be communicated to any third party without the owner’s written consent. © Copyright Airbus DS Electronics and Border Security 2017. All rights reserved.

Airbus Defence & Space carve-out of radar, optronics, EW and avionics business

Airbus DS Electronics & Border Security rebranding from March 1st, 2017 to HENSOLDT

06 July 2017

Presentation Title runs here (go to Header & Footer to edit this text)

2

New Company effective March 1st, 2017: HENSOLDT


• Goal and Basic Design Considerations

• Analysis of Transmitter Network Structure for Germany and Network Model

• Passive Radar Design and System Overview

• Measurement Results

• Lessons Learnt and Conclusion

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Passive Radar Design Study, System Overview and Lessons Learnt:


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Basic Question and Activities

Can a conventional active air surveillance radar be replaced / augmented by a Passive Radar

system, consisting of one or several receiver sites ?

-> 360° az. coverage, ~ 60° el. coverage

-> range ~100km @ typical A/V RCS

-> handling, 3D-localization and separation of a great number of aerial targets

Analyse networks available as illuminators

Design, built and test a prototype system and perform tests to gain experience


1. Ensure multistatic illumination of airspace & targets

2. Suppress strong ‘Direct Signals’ from Tx

3. Detect, fuse detections & separate targets, localize targets

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Multistatic Passive Radar Principles & Problems

Multiple Tx, Single Rx Multiple Rx, Single Tx


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Impressions of Separation Problem in Multi-Target Scenarios

bistatic plot data R-RR tracks & 3D-tracks:

T0

T1


Slant Range (km)

Heig

ht

(km

)

DAB

0 20 40 60 80 1000

5

10

15

-100

-90

-80

-70

-60

-50

-40

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Analysis of Transmitter Networks in Germany: FM, DAB, DVB-T

Broadcast Network

Frequency Band

Transmitter Bandwidth

Typical Transmitter Power (EIRP)

FM radio 88MHz - 108MHz

0 - 100kHz *) 10kW – 100kW

DAB radio

174MHz - 240MHz

1.5MHz 1kW – 10kW

DVB-T (television)

470MHz – 862MHz

7.6MHz 1kW – 100kW

Slant Range (km)

Heig

ht

(km

)

FM

0 20 40 60 80 1000

5

10

15

-100

-90

-80

-70

-60

-50

-40

Slant Range (km)

Heig

ht

(km

)

DVB-T

0 20 40 60 80 1000

5

10

15

-100

-90

-80

-70

-60

-50

-40

Receive Powers:

4π

λ

R4π

(El)GPP

2

2

ssr

DAB DVB-T FM

DVB-T Tx elevation diagram


In SFNs an ambiguity w.r.t. the origin of each received reflexion

exists multiple hypothesis tracking increases complexity !

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Multiple & Single Frequency Networks

MFN

SFN

PR receiver Tx1 Tx2 Tx3

PR receiver Tx1 Tx2 Tx3

f1 f2 f3

https://de.wikipedia.org/wiki/Datei:SFN_model.svg



9

DAB SFN Ambiguity: Measurements in Ulm, Germany

250km

150km


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Data Fusion and Tracking in SFNs / MFNs

FM DAB DVB-T

Plots

(Range, Doppler,

Azimuth)

Plots

(Range, Doppler,

Azimuth)

Plots

(Range, Doppler,

Azimuth, Elevation)

Range-RangeRate

Tracks

Range-RangeRate

Tracks

Range-RangeRate

Tracks

Range-RangeRate Tracking

R

R

R

R

R

Correlation Track to Transmitter

Trk 1

Tx 1

Trk 1

Tx 2

Trk 1

Tx 3

Trk 1

Tx ...

Trk 1

Tx k

Trk 1

Tx 1

Trk 1

Tx 2

Trk 1

Tx 3

Trk 1

Tx ...

Trk 1

Tx l

Trk m

Tx 1

Trk m

Tx 2

Trk m

Tx 3

Trk m

Tx ...

Trk m

Tx k

Trk n

Tx 1

Trk n

Tx 2

Trk n

Tx 3

Trk n

Tx ...

Trk n

Tx l

Trk 1

Tx 1

Trk p

Tx 1

Multi Range-RangeRate Track Fusion

Track Correlations

Target height assuumptions

Gaussian Mixture

Log-Likelihood Ratio

3D-Track 1 3D-Track 2 3D-Track q

Multi Hypothesis Tracking !

How many hypothesis’ ?

Separation of ellipsoids ?


06 July 2017 11

Analysis of Tx Networks in Germany (Area: 357.000km2)

Longitude [°]

Latitu

de [

°]

FM

5.59482 7.59482 9.59482 11.5948 13.5948

55.137

53.137

51.137

49.137

transmitter sites with at least 1 frequency >= 30 dBW

transmitter sites with at least 1 frequency >= 40 dBW

Longitude [°]

Latitu

de [

°]

DAB

5.59482 7.59482 9.59482 11.5948 13.5948

55.137

53.137

51.137

49.137

Longitude [°]

Latitu

de [

°]

DVB-T

5.59482 7.59482 9.59482 11.5948 13.5948

55.137

53.137

51.137

49.137

DAB:

• 176 transmitters >30dBW

• arranged in 33 SFNs

DVB-T:

• 434 transmitter >40 dBW

• arranged in 198 SFNs

FM:

• 145 transmitters >40dBW

• Multiple Freq. (MFN)


06 July 2017 12

Analysis of MFN / SFN Networks in Germany

FM: MFN, Tx-Grid approx. 50km

DAB: 33 SFNs of various size, typ. <10 Tx, max. 53 Tx per SFN

DVB-T: 198 SFNs of various size, <8 Tx per SFN

DAB DVB-T


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Tx Network Model for Germany

PR cov. of 360°, 100km range:

- 16 FM Tx

- 2 .. 4 DAB SFNs

- 2 .. 9 DVB-T SFNs


DVB-T Antenna

· 474-850 MHz

· Calibration Unit

FM/DAB Antenna

· 88-240 MHz

· Calibration Unit

DVB-T Analog Rx

· Amplifier

· Channel Filters

DAB Analog Rx

· Amplifier

· Bandpass Filter

208-234 MHz

FM Analog Rx

· Amplifier

· Bandpass Filter

88-108 MHz

DVB-T Digital Rx

· ADC

· DDC

DAB Digital Rx

· ADC

· DDC

FM Digital Rx

· ADC

· 8 x DDC

DAB Signal Proc.

· Adaptive BF

· Correlation

· Detection

· Azimuth Meas.

FM Signal Proc. 8ch.

· Adaptive BF

· Correlation

· Detection

· Azimuth Meas.

DVB-T Signal Proc.

· Adaptive BF

· Correlation

· Detection

· Azimuth/Elev.

Meas.Tracking System

· Range-Doppler

Tracking

· Multihypothesis

Tracking (DAB/

DVB-T)

· Data Fusion

· 3D-Tracking

Engineering Consoles

Signal Proc./Tracking

· Range-Doppler Display

· Bearing Results

· Tracking Results

Operator Console

ViSys

14

56

7

14 14

7

7

7

Plots

Plots

Plots

Tracks

ADS-B Rx

Reference

Clock Generator

GPS

Calibration Signals

Clocks

Mission Planning Tool

HD Recording

Multiband Antenna

Analog Receiver Digital Receiver Signal Processing Tracking

MMI / Visualisation

ADS-B

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Passive Radar System Design


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Passive Radar Multiband Demonstrator System

Multiband coverage simultaneously processible transmitters:

– 8x/16x independent FM transmitters

out of FM Band 88 – 108 MHz

– 1*x DAB Single Frequency Network (SFN)

out of DAB Band 174 – 240 MHz

– 1*x DVB-T Single Frequency Network

out of DVB-T Band 474 – 786 MHz (* 3 SFN parallel)

Processing:

– Realtime signal processing

(Bistatic Plotdata)

– Realtime 3D tracking system

(including multihypothesis tracking for SFN &

multi-sensor-tracking for sensor cluster operation )


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Single-Site Measurement Campaigns

2014 16

Berlin Schoene-

feld Airport

Berlin Tegel Airport

Berlin Tegel Airport

Berlin Schoene-

feld Airport

1 FM transmitter:

- range up to 100km

- covarage gaps

- accuracy >1km

8 FM transmitters:

- range up to 100km

- no covarage gaps

- accuracy <500m

Berlin Area, Germany, FM only

Lake Constance Area, Germany

FM, DAB, DVB-T

Visualization of multistatic diversity:

Video: FM_DAB_DVB-T-Video

1221692_996x560_H264_1400.mp4

1221692_996x560_H264_1400.mp4

1221692_996x560_H264_1400.mp4

1221692_996x560_H264_1400.mp4

1221692_996x560_H264_1400.mp4


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Dual-Site Operation

PCL1 (Master)

Signal-Processing

FM & DAB & DVB-T

LAN

bistatic plot

data

PCL2 (Slave(s))

Multi-Sensor-Tracking

(data fusion of bistatic plot data

and dislocated sensors)

Signal-Processing

FM only 3G

bistatic

plot data

3D air picture using ASTERIX exter-

nally over 3G link online / real time

LAN

bistatic plot

data

Track data in ASTERIX for

distribution or display

CRC / Network

Track data in

ASTERIX

Passive radar sensor cluster provides:

• increasing coverage

• increasing accuracies

Sebastian Stroth - Spexer and Passiv Radar Engineering, HENSOLDT Slide 17 2017

http://www.animaatjes.de/malvorlagen/malvorlagen/flugzeug/flugzeug-malvorlagen-0.gif


Airport MUC

70km

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Dual-Site Measurement Campaign

Sebastian Stroth - Spexer and Passiv Radar Engineering, HENSOLDT 3 September 2015 Slide 18 2017


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Passive Radar System Design


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Evaluation of Combined Multistatic Plot Updates

Color Code:

# number of plot updates to

3D-track per second

Min 3 updates / second

Max 30 updates / second

Provides by

- 2 x 8 FM Tx

- 1 DAB SFN

- 1 DVB-T SFN

Visualization of site-siversity:

Video_Site_and_Tx_Diversity

_Teil2.wmv


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Lessons Learnt: Passive Radar Diversity Approach

Target detection by each one transmitter-receiver-constallation is limited by:

- terrain shadowing, esp. in low altitude targets

- multipath fading, both in the Tx-Target path and in the Target-Rx path

- angle-dependent target RCS fluctuation

- transmitter antenna elevation beamwidth, i.e. target illumination

- bistatic-range-dependent clutter characteristics

- PR blind zones (e.g. zero-doppler target trajectories)

Make use of diversity w.r.t. multiple Tx networks & frequency bands and multiple receiver sites


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Summary

Transmitter network analysis (Germany):

- model for FM/DAB/DVB-T Tx grids, Tx power and elevation cov.

Passive radar system demonstrator built and optimised in several steps:

- FM

- DAB / DVB-T

- cross-band data fusion and tracking

- second PR receiver station (FM only) for receiver site diversity

Measurement results:

- FM: range 100km+, acc. ~ 500m

- DAB/DVB-T: range 50km+, acc. ~ 50m

Reliable wide area coverage:

- Tx diversity: 8...16 FM Tx, 1..4 DAB/DVB-T SFNs

- Rx diversity: multiple receiver sites

FM/DAB/DVB-T Multiband Multistatic Passive Radar System...

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