The RADARSAT-Constel lat ion Mission (RCM)

Dr. Heather McNairnScience and Technology Branch, ORDCheather.mcnairn@agr.gc.ca

Daniel De LisleRADARSAT Constellation Mission ManagerCanadian Space Agencydaniel.delisle@canada.ca

Why Synthetic Aperture Radar (SAR)?

The Physics:• At microwave frequencies, energy causes alignment of dipoles

(sensitive to number of water molecules in target)• Characteristics of structure in target impacts how microwaves

scatter (sensitive to roughness and canopy structure)

The Operations:• At wavelengths of centimetres to metres in length, microwaves

are unaffected by cloud cover and haze• As active sensors, SARs generate their own source of energy; can

operate day or night and under low illumination conditions

The Reality for Agriculture:• The backscatter intensity and scattering characteristics can be

used to estimate amount of water in soils and crops, and tell us something about the type and condition of crops

• The near-assurance of data collection is critical for time sensitive applications, in times of emergency (i.e. flooding), risk (i.e. disease), and for consistent measures over the entire growing season (i.e. monitoring crop condition)

Why a RADARSAT Constellation?

• The use of C-Band SAR has increased significantly since the launch of RADARSAT-1 • Many Government of Canada users have developed operational applications that deliver

information and products to Canadians and the international community, based on RADARSAT• This constellation ensures C-Band continuity with improved system reliability, primarily to support

current and future operational users• RCM is a government-owned mission, tailored to respond to Canadian Government needs for

maritime surveillance, disaster management and ecosystem monitoring

AAFC’s annual crop inventory

Produced by ACGEOContact: Andrew.Davidson@agr.gc.ca

Improved stream flow forecasts1 Estimates of crop biomass2

1Bhuiyan, H.A.K.M, McNairn, H., Powers, J., and Merzouki, A. 2017. Application of HEC-HMS in a cold regions watershed and use of RADARSAT-2 soil moisture in initializing the model. Hydrology. 9: doi: 10.3390/hydrology4010009.

2Hosseini, M., and McNairn, H. 2017. Using multi-polarization C- and L-band radar to estimate biomass and soil moisture for wheat fields. International Journal of Applied Earth Observation and Geoinformation. 58: 50-64.

The Evolution of RADARSAT

RADARSAT-1 RADARSAT-2 RCM

# satellites 1 1 3

Centre frequency 5.3 GHz 5.405 GHz 5.405 GHz

Exact revisit 24 days 24 days 12 day (each satellite)4 days (constellation)

SAR time/orbit 28 min 28 min 15 min/sat

Polarization HH HH, VV, HV, VH (Quad) HH, VV, HV, VH (quad)Compact pol.

Look direction Right Right or Left Right

Altitude 800 km 800 km 600 km

Descending node 6 h 6 h 6 h +/- 15 min

Ascending node 18 h 18 h 18 h +/- 15 min

RADARSAT-1 (1997-2013)16 years RADARSAT-2 (2007-)

RADARSAT-Constellationlaunch 2018

RCM improvements

• Average daily revisit of any point over Canada• Exact 4-day repeat (as opposed to 24-day for R-1/2)

allowing for 4-day coherent change detection• Compact polarimetry

• Satellites will be equally spaced, 120 degrees apart

• Per satellite, 15 minutes of imaging time per orbitDaily coverage with RADARSAT-24 days required for complete coverage

Daily coverage with RCMComplete average daily coverage

Image credits: CSA , MDA

Canadian receiving stations

Ground segment is based on existing infrastructure, using the national Gatineau, Prince Albert, and Inuvik stations for data reception and Telemetry Tracking & Command

Image credit: Canadian Space Agency

Image credit: Canadian Space Agency

Specs for RCM imaging modes

Image quality

Cal/val will be performed using natural reference sites and artificial targets

• Two new precision instruments installed at St-Hubert (CSA HQ and nearby)

• Six corner reflectors will be deployed for RCM at three locations

R&D is ongoing for the development of an advanced methodology to calibrate operationally RCM compact polarimetry Image credits: Canadian Space Agency

Projected timelines

Image credits: Canadian Space Agency

Testing in thermal vacuum chamber (January 2017)

Vibration and shock testing (summer 2017)

Spacecraft status

• The first spacecraft has completed Integrated System Test and mission-mode electro-magnetic compatibility (EMC) is underway;

• The second spacecraft's two modulator units were found to be faulty and were removed and sent to sub-contractor. A repair scheme has been developed and implemented. Testing is scheduled to restart in mid-February;

• The third spacecraft has completed Integrated System. The Integration campaign is on hold, as its X-band downlink modulators have been returned to the supplier for repair;

• The launch in now planned for October 2018 (Space X Falcon 9 vehicle at Vandenberg Airforce Base, California)

Standard coverages

• RCM was designed primarily for Government of Canada “operational purposes”

• RCM will systematically and recurrently image large areas in support of specific requirements

• Predominantly over the Canadian Area of Interest• Designed to offer consistent and predictable SAR coverage• Long-term data archive built for exploitation of information based on long time

series

• Standard coverages consist of pre-defined and pre-planned data acquisition plans that are based on a common set of parameters such as imaging modes and geographic areas

• Coverage plans are expected to be published on-line weeks/months ahead of acquisition (unless restricted for security reasons)

RCM advancements important for agriculture

Rapid and Frequent Revisit

Compact Polarimetry

HH+VVMode

Needed for soil moisture modeling

Needed for monitoring changing conditions

Crop condition, harvesting, soil moisture etc.

An information rich mode with up to 500 km coverage

for use in crop mapping; crop condition and soil moisture

monitoring

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