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11/10/202263rd IAC Conference Naples, Italy

Multistatic small SAR Network for Oil

Monitoring in Nigeria

Abdul Duane Lawal

Background (I) Benefits of space generated data.

• Communication• Disaster monitoring and mitigation• Earth observation• Weather forecasting

Net contribution of space missions• Education (spans multi-disciplinary aspects, e.g. medicine & law)

• Revenue (television, remote sensing, manufacturing, launch services)

• Security (dissemination of quick and timely information to support decision making)

• Science (environment security, e.g. climate change)

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Background (II) Several nations have failed to embrace space science and technology

WHY? - Mission cost!! Who are these nations? Developing nations (156 – IMF Advanced Economics List, April 2012)

Over 45 developing nations geographically located around the Equatorial Region (ER)

Vast amount of resources within the ER• Tin, copper aluminium. OIL…..

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Introduction Nigeria – 7th largest exporter of oil Threat to source of revenue

• Oil bunkering: estimate between 100,000 & 130,000 barrels per day stolen

Threat by source of revenue• Oil spill: potential hazard to marine life (e.g. New Zealand ‘11 & US ‘10)

24 hours oil monitoring Close neighbours along the Gulf of Guinea mostly developing nations

Hence the need for collaboration

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Mission Objectives Low cost space mission 24 hour surveillance of the Gulf of Guinea Monitor oil resources Detection of oil spills High resolution data Low temporary resolution Near Real Time (NRT) data acquisition Investigate the possibility of a small SAR Network for the ER

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M01 Mission Design M01 – baseline monostatic SAR satellite Orbit type – circular near equatorial Baseline orbit of 700 km

• Establish a basis of comparing acquired images with NigeriaSat-2 images

• Facilitate on-the-job training• Complement image classification in event of ambiguities

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M01 Baseline Orbit Altitude (Km) 700

Revs/day 14.5Inclination (deg) 10Period (mins) 98.7RAAN (deg) 0

M01 System Parameters Active remote sensing required for 24 hours surveillance• SAR

ALOS, RADARSAT-1/2 & ENVISAT operated at C-band

Recent investigations show better contrast ratio for oil spill detection• X-band frequency (TerraSAR-X, TANDEM-X & COSMO SkyMed)

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M01 System Parameters

Operating band X

Frequency 9.6

PRF (Hz) 2710

Bandwidth (MHz) 44

Antenna Length (m)

6

Antenna width (m) 0.7

Incidence Angle (deg)

45

Resolution (m) 3

M01 Coverage Analysis Coverage analysis over the ER for 24 hour period using STK

M01 potentially has access to 100% of ER Average time of 12% of overall time spent on selected latitude boundary

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Latitude (deg)

Time covered (%)

Total time covered (mins)

-9 12.76 183.75-7 13.20 190.15-4 15.51 194.54-2 13.69 197.140 13.76 198.082 13.71 197.384 13.54 195.027 13.26 190.899 12.83 184.78

Near Polar orbit vs Near Equatorial Orbit

Comparison between NigeriaSat-2 (N2) and M01 access to Abuja groundstation

N2 has 3.6 % access time daily M01 has 13 % access time daily

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NigeriaSat-2

M01

Payload MRI/VHRI SAR

Altitude (km) 700 700

Inclination (deg) 98 10

Orbit period 98 98

Average number of daily passes

4 14

Average duration of pass (min)

10 13.5

Total average daily access (min)

40 189

M01 & M11 Coverage Analysis

Investigating possibility of collaboration• Reduced overall mission cost at increased available data• Promote international collaboration• Redundancy

M11 – same baseline design parameters• In-orbit separation of 180 degrees between M01 & M11

A combination of 28 passes at 25.56% access time daily

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Constellation Design Approach

Low cost mission approach• Smaller satellites

Semi-active operation• One master satellite (M01)

o Typical monostatic SAR : Transmit/ Receive (Tx/Rx)• Three slave satellite (S01, S02, S03): Receiver –only (Rx)

Two groups of semi-active configuration (constellation)• Group 0: (M01, S01, S02, S03)• Group 1: (M11, S11, S12, S13)• Each group flying in close formation in a pendulum configuration in 2 orbitso M01 & M12: same inclination, RAAN and different mean anomaly (180°)

o S01, S02, S03 and S11, S12, S13 : same inclination, different RAAN with 180° in-orbit separation between both groups of slaves

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Constellation Simulation

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Ground Segment Sites Five sites selected as possible

ground segment locations• Accra, Cayenne, Mogadishu,

Singapore & Tarawa Based on existing space

capability and nearness to Equator

Max time between successive ground station contact: <10mins

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Distributed small SAR Network for Equatorial

Region

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Access for a S/C within network

14 x 5 accesses daily Rapid data capture rate

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Opportunity to interferometric applications to the limit

Avenue for lesson Platform for rapid development

Conclusion Near equatorial inclined orbits for small SAR network EO mission is well suited for oil monitoring in Nigeria• Payload is capable of sensing the area of interest on every pass• Access to ground station on every pass• 24 hours surveillance• Possibility to acquire various types of data

Application of small SAR missions for ER has potential benefits• Ushers the possibility of a consortium of Tropical countries• Provides low cost affordable mission to developing nations• Support urban development• Nations will become DATA-FULL• It is achievable

Future Work• Investigating

o the stability of the pendulum configurationo Other application areas

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Space Glasgow@SpaceGlasgow

www.glasgow.ac.uk/space