SMAP will provide a capability for global mapping of soil moisture and freeze/thaw state with unprecedented accuracy, resolution, and coverage. The SMAP mission will include a microwave radiometer and a radar, both operating at frequencies in the L-band range. At such wavelengths (~ 20 cm), the electromagnetic signal is sensitive to moisture in a thin surface soil layer (2-10 cm, in optimal conditions depending mainly on the soil water content). The radiometer will provide brightness temperatures at the 1.41-GHz frequency, which is protected by international regulation for passive services. Radiometric observations from SMAP will provide accurate measurements of soil moisture through moderate vegetation of up to approximately 5 kg/m2 water content, which corresponds to mature crop fields. The radar will measure surface backscatter at the 1.26-GHz frequency, with greater horizontal resolution than the radiometer but with less accuracy and more sensitivity to vegetation water content and soil roughness. Because of its radar capability, SMAP will also provide high-resolution global mapping of the surface freeze/thaw state.
SMAP will operate on a near-polar, sun-synchronous orbit approximately 680 km above the Earth surface, with a 6AM/6PM Equator crossing and an 8-day repeat ground-track. The swath width will be on the order of 1000 km, which will provide global coverage every 3 days at the Equator, and every 1-2 days at mid and high latitudes. The 6-m diameter deployable mesh antenna with 40o incidence angle will ensure a 40-km footprint for the radiometer and 30-km real aperture footprint for the radar. Range and Doppler discrimination combined with further processing will be used to obtain a 1-3 km spatial resolution for radar measurements, in a synthetic aperture radar (SAR) mode. Passive and active observations will be combined by processing and by data assimilation algorithms to produce accurate soil moisture estimates at an intermediate horizontal resolution of 10 km.
In contrast with its predecessor mission Hydros, SMAP is a NASA directed mission, with no direct contribution from Canada on satellite or instrument development and/or construction. In spite of this, and because of the strong interest expressed by the Canadian scientific and operational communities for this mission (as was also the case for the Hydros mission), the Canadian Space Agency (CSA) has agreed to partner with Environment Canada (EC) to develop and support the implementation of a Canadian Science and Applications Plan for SMAP.
The Canadian Science and Applications Plan
This involvement of CSA, based on an implementing agreement with NASA, will allow Canadian scientists to work in collaboration with US and other international partners on scientific and operational aspects of the mission. In addition to the benefits related to sustainable development and climate change, SMAP will reinforce Canada's expertise in several key scientific areas such as land data assimilation for numerical environmental prediction (weather, climate, hydrology, agriculture, forests), as well as radiometric and radar remote sensing of the land surface to retrieve soil moisture and the freeze/thaw state.
Canada's scientific contribution to SMAP will consist of i) calibration and validation of SMAP measurements and retrievals (active and passive, soil moisture and freeze/thaw), and ii) research, development, and applications.
| NAME | INSTITUTE | LEAD PROJECT |
|---|---|---|
| Stéphane Bélair | Environment Canada / Meteorological Research Division | Lead of Canadian science team (data assimilation, NWP, air quality). |
| Aaron Berg | University of Guelph | Improved root zone soil moisture retrieval using data from the SMAP Validation EXperiment in 2012. |
| Monique Bernier | Institut national de la recherche scientifique / Eau, terre et environnement | Development of SMAP freeze/thaw algorithms adapted for the Canadian tundra. |
| Paul Bullock | University of Manitoba | Integration of remote sensing data, in situ soil moisture, and soil moisture modeling for improved soil moisture observation. |
| Jing Chen | University of Toronto | Assimilation of soil moisture in an ecosystem model for SMAP. |
| Chris Derksen | Environment Canada / Climate Research Division | Freeze/thaw calibration and validation (Cal/Val). |
| Ramata Magagi | University of Sherbrooke | Estimation of soil moisture from L-band passive and active microwave data over Canadian agricultural and forested areas. |
| Heather McNairn | Agriculture and Agri-Food Canada | Soil moisture field measurements, microwave remote sensing, agriculture. |
| Alain Royer | University of Sherbrooke | Passive microwave soil freeze/thaw monitoring and Cal/Val for the SMAP mission. |
| Brenda Toth & Erica Tetlock | Environment Canada / National Hydrology Research Institute | Soil moisture field measurements. |
Dr. Stéphane Bélair, research scientist at EC / MRD, is responsible for the overall implementation of the Canadian Science and Applications Plan for SMAP.
The SMAP Validation Experiment in 2012 (SMAPVEX12) was conducted in southern Manitoba in summer 2012. Detailed information concerning this field campaign can be found at this site: http://pages.usherbrooke.ca/smapvex12/
1) The first Canadian SMAP workshop took place at Environment Canada's Biosphere, Montreal, on 6-7 October 2009. The agenda and presentations are available at: http://smap.jpl.nasa.gov/science/workshops/index.cfm?FuseAction=ShowNews&NewsID=15&newsTypeID=2
2) The second Canadian SMAP workshop was held at the Canadian Meteorological Centre, in Montreal, on 16-17 November 2010. The agenda and presentations are available at: http://smap.jpl.nasa.gov/science/workshops/index.cfm?FuseAction=ShowNews&NewsID=80&newsTypeID=2
3) The third Canadian SMAP workshop was held at the Agriculture and Agri-Food Canada experimental farm site, in Ottawa, on 20-21 March 2013. The agenda and presentations are available at: http://smap.jpl.nasa.gov/science/workshops/index.cfm?FuseAction=ShowNews&NewsID=148&newsTypeID=2
Information concerning all other SMAP meetings and workshops is available at: http://smap.jpl.nasa.gov/science/workshops/