Professor Paul Siqueira of the Electrical and Computer Engineering Department at the University of Massachusetts Amherst has been selected to serve as one of the Co-Leads for an $800-million collaborative space mission being carried out by NASA and the Indian Space Research Organization (ISRO). Siqueira was already one of 20 scientists chosen to guide the NASA-ISRO satellite mission to observe Earth and to study “Earth Deformation, Ecosystem Science, and the Dynamics of Ice.”
The Science Definition Team is a group of 20 scientists nationwide who are considered experts in their field and who help direct the formulation of the mission. The current launch readiness date is 2021.
After spending four years in the formulation phase of the mission, Siqueira will now lead the “Ecosystems” phase of the massive project and will also carry out the components of his recent proposal accepted by NASA and entitled “Development of NISAR Ecosystems Applications for Calibration/Validation and to Meet Mission Goals and Requirements,” submitted to the Science Mission Directorate of NASA’s Earth Science Division.
The NASA-ISRO Synthetic Aperture Radar, or NISAR, satellite is designed to observe and take measurements of some of the planet's most complex processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes, and landslides. NISAR will be the first satellite mission to use two different radar frequencies (L-band and S-band) to measure changes in our planet’s surface less than a centimeter across. This allows the mission to observe a wide range of changes, from the flow rates of glaciers and ice sheets to the dynamics of earthquakes and volcanoes. The NISAR mission will observe much of the Earth’s land surfaces at a 20m resolution, every 12 days. Data from satellite, some three TB/day, will be made freely available to the public through NASA’s Distributed Active Archive Centers (DAACS), part of Earth Observing and Data Information System (EOSDIS).
For the NISAR mission, NASA will provide the mission’s L-band synthetic aperture radar (SAR), a high-rate communication subsystem for science data, GPS receivers, a solid state recorder, and a payload data subsystem. ISRO will provide the spacecraft bus, an S-band SAR, and the launch vehicle and associated launch services.
As Siqueira said in 2014 about his placement on the Science Definition Team, “My personal responsibility is to work on the science applications [of the NISAR mission]. With the interaction of NASA and Jet Propulsion Laboratory staff scientists/engineers, the Science Definition Team works with the mission planners to determine a configuration and observing strategy to make best scientific use of the satellite resources (observing time, power consumption, data rate, etc.).”
Siqueira’s expertise in microwave sensor development is applied to carbon accounting, habitat identification, and monitoring of forest resources on Earth.
“The advantage of a space-borne mission is that such studies can be extended globally to make large-scale, high fidelity, measurements of the ecological environment,” observed Siqueira. “My background as an engineer and applications scientist is what have allowed me to effectively communicate (and understand) the tradeoffs involved in obtaining the needed science with the instrument that will ultimately be launched.”
Now, due to NASA’s acceptance of his recent proposal, Siqueira will lead the effort to accomplish three basic objectives during the NISAR mission. The first is to participate in the Ecosystems component of the NISAR Science Definition Team. The second is to continue development of the NISAR mission requirements for the applications of agriculture, disturbance, biomass, and inundation sub-disciplines through the creation, evaluation, and validation of observational error models which will be developed into a NISAR mission-wide performance model at the NASA Jet Propulsion Laboratory in Pasadena. Lastly, Siqueira will continue to lead the agricultural component of the NISAR mission and help foster the applications community for this aspect of the project.
As Siqueira has explained, the world's growing population is experiencing unprecedented changes to our climate through intensifying events such as floods, droughts, and wildfires, hurricanes and tornadoes, and insect infestations and related health effects. These impacts are putting pressure on our landscapes and ecosystems that generate food, fiber, energy, and living spaces for a growing global population. It is imperative to understand the connections between natural resource management and ecosystem responses to create a sustainable future.
With these factors in mind, the “Ecosystem” phase of the NISAR mission has the following objectives:
- Enhance knowledge of ecosystem structural dynamics to determine environmental change and ecological impacts.
- Determine the changes in carbon storage and uptake resulting from disturbance and subsequent regrowth of woody vegetation.
- Determine the area and crop aboveground biomass of rapidly changing agricultural systems and land use patterns.
- Determine the extent of wetlands and characterize the dynamics of flooded areas.
- Characterize freeze/thaw state, surface deformation, and permafrost degradation.
- Explore the effects of ecosystem structure and its dynamics on biodiversity and habitat.
Siqueira has a long history with NASA projects. Prior to the NISAR project, NASA’s Earth Science Technology Office had asked researchers at UMass Amherst to participate in building a satellite-borne instrument that would allow scientists to forecast weather and climate changes with unprecedented accuracy. Siqueira was the principal investigator on that team, whose task was building an interferometric receiver to measure the “topography” and temperatures of Earth’s waters and give us unparalleled insights into the dynamics of our global climate.
Before coming to UMass in 2005, Siqueira was at the NASA Jet Propulsion Laboratory, where he worked on the engineering of airborne and space-borne microwave remote sensing systems and their application to earth sciences. Among many important projects he worked on were NASA’s Shuttle Radar Topography Mission and the Japanese Aerospace Exploration Agency’s Global 2 Rainforest Mapping Project. (June 2016)