Carnegiea gigantea forest, Saguaro National Park, Tucson, Arizona

Our Research

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Current Projects

Haboob blowing into Ahwatukee, Phoenix, Arizona on 22 August 2003.
Image: Public Domain Junebug172

The Planetary Boundary Layer (PBL) is the atmospheric region closest to the ground which directly influences human activity. Improved PBL observation by satellites has the potential to advance wide-ranging scientific problems including weather and air quality forecasting, climate modeling, and pollution emissions and transport.

The objective of this project is to establish an observing system simulation experiment (OSSE) platform that can analyze the performance of future PBL observing missions. Deploying an OSSE helps identify and refine preferred designs within a large architectural trade space.

This project adapts the Tradespace Analysis Tool for Constellations (TAT-C) to ingest environmental data sets such as the GEOS 5 Nature Run (G5NR) and produce observable regions for each mission architecture for further analysis using the Parallel OSSE (ParOSSE) platform developed at the NASA Jet Propulsion Laboratory.

Water vapor animation for the afternoon of August 22, 2018 showing the monsoon circulation and thunderstorm formation (dark blue, green, dark red). Dry air is shown in orange.
Image: Public Domain National Weather Service

The National Oceanic and Atmospheric Administration (NOAA) operates a constellation of satellites that collect information for short- and long-term weather forecasts. The objective of this project is to develop automated assessment methods and tools to explore future NOAA mission concepts that may rely on distributed or decentralized architectures.

This project works with the Advanced Systems Performance Evaluation for NOAA (ASPEN) tool which uses a Sensor/Constellation Performance (SCP) table to structure front-end inputs for mission evaluation. The SCP table contains observation performance attributes for a range of geophysical variables relevant to NOAA. This project uses the Tradespace Analysis Tool for Constellations (TAT-C) to automatically conduct coverage/sampling analysis (e.g., temporal refresh and data latency) for new mission concepts. Additionally, this project interfaces with the Parallel Observing System Simulation Experiment (ParOSSE) tool developed at NASA’s Jet Propulsion Lab to estimate resolution and accuracy of future space-based observations.

Rocky Mountain National Park, Colorado-16.
Image: CC-A-SA Sarbjit Bahga

Snow is a seasonal environmental process that deposits a reflective, insulating cover over the Earth’s land mass that supports numerous ecosystems and provides water supply to one in four people globally. While numerous existing or expected satellite sensors are sensitive to snow and provide information on snow properties, none provide global snow water equivalent (SWE) data at the frequency, resolution, and accuracy to address key hydrological science questions.

The National Academies identified SWE or snow depth as a critical observation in the 2017-2027 Decadal Survey and recommend it as a measurement priority for Earth System Explorer (ESE) class missions. The evolution of snow cover throughout the year is highly dependent on geographical regions, latitudes, and elevations. For example, peak SWE and SWE uncertainty in North America shifts from lower latitudes and elevations in January-April to northern latitudes and elevations in May-June. Seasonal snow is an ideal candidate for an optimized observational strategy that leverages existing sensors and focuses future mission concepts on the most critical areas to provide cost-effective and robust information to improve scientific knowledge.

The objective of this project is to develop a Snow Observing System (SOS) to estimate global SWE and snow melt throughout the season, targeting observations with the greatest impact to spatially- and temporally-varying hydrological metrics. The observing strategy behind SOS targets high-resolution observations in critical areas, taking advantage of new commercial small-satellite platforms which are becoming increasingly available to science applications with innovative operational tasking requests.

Rain falls from monsoon clouds over the Phoenix area, Arizona
Image: CC-A-SA Nicholas Hartman

This project designs and evaluates collaborative mission concepts to observe convective storm systems. Remote sensing of convective storm systems benefits from responsive operations to identify and monitor cloud dynamics and convective processes to better understand the formation and evolution of storm systems and the effects of climate change at regional and global scales.

Future observing systems with inter-agency, international, and commercial partners constitute a system-of-systems because each partner pursues their own objectives on different development timelines. System-of-systems architecting follows more indirect principles such as identifying stable intermediate forms and exerting leverage at the interfaces.

Co-simulation is an information technology for design, evaluation, and maturation of system-of-systems concepts throughout the system lifecycle. It provides distributed control over constituent systems and allows partners to integrate constituent simulators despite differences in modeling frameworks and languages or other information sharing barriers due to legal or proprietary issues. Applied to convective storm observing systems, co-simulation demonstrates and validates new operational concepts such as alerting, scheduling, and dynamic pointing across organizational boundaries.

A co-simulation platform integrates simulation models of mission and partner nodes through a loosely coupled service-oriented architecture. Front-end mission design activities propose new mission concepts by varying the number of satellites, orbital geometry, and instrument characteristics. Co-simulation executes a joint scenario by coordinating member simulator execution across an information infrastructure. Finally, a back-end science evaluation engine maps collected scenario observations to a measure of scientific utility to evaluate effectiveness.

Image of two cubesats in space.
Image: Public Domain NASA

This Faculty Early Career Development Program (CAREER) grant diagnoses and provides understanding of strategic dynamics among a set of interactive and autonomous design actors through the combined use of game theory and simulations to inform architecture and design decisions. Design activities for engineering systems across infrastructure, aerospace, and defense domains more closely resemble a collective decision-making process than centralized authority in traditional systems engineering practice. This topic is of interest because U.S. agencies and firms are actively architecting systems with decentralized decision authority, described variously as Internet 4.0, cyber-physical systems, Internet-of-things, or systems-of-systems across domains, including energy, transportation, manufacturing, and space systems. The design of these engineering systems differs from that of other systems because their large scale, long lifetime, and proximity to social systems evoke complex features such as adaptation, self-organization, and emergence, which take place over strategic timescales. A deeper understanding of how strategic dynamics impact designer interactions across theoretical and empirical perspectives can help to avoid costly overruns and cancellations by identifying and mitigating undesirable dynamics in conceptual design phases. Advances in systems engineering must develop theory, methods, and tools to coordinate and facilitate collective design activities.

This project builds on a line of economic methods applied to engineering design including utility theory, decision theory, social choice, and game theory. Collective systems design is modeled as a bi-level problem, where lower-level decisions correspond to an optimization problem and upper-level strategy decisions correspond to a coordination game. Normative models of agent behavior are based on classical and Bayesian game theory with utility functions incorporating behavioral factors such as risk attitudes. Multi-agent simulation studies evolution of strategies under repeated interaction among agents. Behavioral experiments collect empirical data about human decision-making for validation. The research will contribute new knowledge about how to characterize, study, and modify the strategic dynamics of engineering systems during conceptual design phases. The educational plan develops and delivers simulation activities to model systems problems by combining technical modeling and social interaction. The simulation activities behave as a highly abstracted model system to elicit rich strategic behaviors through face-to-face interaction, engage students with challenges of socio-technical problems, and retain computational tractability to teach analytical methods in educational contexts. Development and broad public dissemination of simulations in the context of Earth science space missions will expose a wide audience to strategic issues of government-commercial interdependency in space systems.

Past Projects

The New Observing Strategies (NOS) initiative within the NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program envisions future Earth science missions with distributed sensors (nodes) interconnected by a communications fabric that enables dynamic and intelligent operations. Some NOS concepts resemble systems-of-systems or collaborative systems where operational authority is distributed among multiple systems, necessitating new methods for systems engineering and design to cope with more decentralized control over constituent systems. 

The New Observing Strategies Testbed (NOS-T) is a computational environment to develop, test, mature, and socialize NOS operating concepts and technology. NOS-T provides infrastructure to integrate and orchestrate user-contributed applications for system-of-systems test cases with true distributed control over constituent elements. The overall concept, illustrated below, interconnects individual user applications and a NOS-T manager application via common information system infrastructure to coordinate the execution of virtual Earth science missions. NOS-T enables principal investigators to conduct test case executions in the same environment, systematically changing variables to assess the overall efficacy of the proposed new observing strategies. Recorded data and outcomes provide evidence to advance technology readiness level and improve upon or innovate existing Earth science measurement techniques. 

The project git repository containing tools, examples, and further documentation can be found here:


Journal Articles
Conference Papers
  • P.T. Grogan, S. Bentley, G. Lordos, K. Latyshev, I. Brown, and O. de Weck (2024). Space Logistics Campaign Scenario Specification for SpaceNet. AIAA-2024-1555. AIAA SCITECH 2024 Forum. (Online)
  • S. Arya, J. Yang, P.T. Grogan, and Y. Wang (2024). Real-time UAV Collaborative Beam Reforming for Coexistent Satellite-Terrestrial Communications,” 2024 IEEE Aerospace Conference, pp. 1-10. (Online)
  • J. Bardaji, A. Bayazid, J.I. Tapia, and P.T. Grogan (2024). Applying the Tradespace Analysis Tool for Constellations (TAT-C) for Earth Science Mission Analysis,” 2024 IEEE Aerospace Conference, pp. 1-9. (Online)
  • R.S. Schaefer and P.T. Grogan (2024). Collaborative Constellation Analysis Framework for Wildfire Observing Missions, 2024 IEEE Aerospace Conference, pp. 1-11. (Online)
  • J. Cairns, Z. Horton, J.I. Tapia, and P.T. Grogan (2024). Tradespace Analysis Capabilities for the Next Generation of the Joint Polar Satellite System (JPSS). 2024 IEEE Aerospace Conference, pp. 1-9. (Online)
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  • A.Z. Avsar and P.T. Grogan (2023). “Identification of designer search strategies and their effects on performance outcomes in pair parameter design tasks,” 2023 ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC-CIE), August 13-16, Boston, Massachusetts.
  • J.I. Tapia and P.T. Grogan (2023). “Dynamic targeting for precipitation observing missions: Integrating the GEOS-5 nature run data set,” 2023 IEEE International Geoscience and Remote Sensing Symposium, July 16-21, Pasadena, California.
  • J. Bardaji, A. Bayazid, J.I. Tapia, E. Cho, C. Vuyovich, and P.T. Grogan (2023). “Constellation evaluation tools for a new snow observing strategy,” 2023 IEEE International Geoscience and Remote Sensing Symposium, July 16-21, Pasadena, California.
  • J.I. Tapia and P.T. Grogan (2023). “Efficient coverage methods for earth observing tradespace analysis,” 2023 IEEE International Systems Conference (SysCon), April 17-20, Vancouver, Canada.
  • P.T. Grogan and J.I. Tapia (2023). “Using JSON Schema to model satellite systems in the Tradespace Analysis Tool for Constellations,” 2023 Conference on Systems Engineering Research (CSER), March 16-17, Hoboken, New Jersey.
  • J.I. Tapia and P.T. Grogan (2023). “Analysis of ground network selection for data latency in precipitation-observing space missions,” 2023 IEEE Aerospace Conference, March 4-11, Big Sky, Montana.
  • M.J. LeVine, B. Chell, and P.T. Grogan (2023). “Leveraging a digital engineering testbed to explore mission resilience for new observing strategies,” AIAA SCITECH 2023 Forum, January 23-27, National Harbor, Maryland.
  • L. Capra, M.J. LeVine and P.T. Grogan (2023). “Demonstration of a utility-based priority algorithm for filtering commercial satellite tasking requests,” AIAA SCITECH 2023 Forum, January 23-27, National Harbor, Maryland.
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Conference Papers
  • Chell, B., LeVine, M. J., Capra, L., Sellers, J. J., Grogan, P. T. (2022). “Conceptual Design of Space Missions Integrated with Real-Time, In Situ Sensors,” International Society of Transdisciplinary Engineering 2022, July 5-8. Cambridge, MA.
  • Avsar, A. Z., Chiesi, S. S., Grogan, P. T. (2022). “Effects of Data Exchange Methods on Perceived Risk and Trust in Digital Engineering,” International Society of Transdisciplinary Engineering 2022, July 5-8. Cambridge, MA.
  • Avsar, A. Z., Stern, J. L., Grogan, P. T. (2022). “Measuring Risk Attitudes for Strategic Decision-Making in a Collaborative Engineering Design Process,” 2022 ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC-CIE), August 14-17, 2022, St. Louis, Missouri.
  • Tapia-Tamayo, I. J., Grogan, P. T. (2022). “Tradespace Analysis of Cross-Calibration in Missions Observing Ocean Color,” 2022 IEEE International Systems Conference (SysCon), pp. 1-8. IEEE, 2022.
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Book Chapters

  • Panchal, J.H. and P.T. Grogan (2021). “Designing for technical behaviour,” in Handbook of Engineering Systems Design, A. Meijer, J. Oehmen, and P. Vermaas (Eds.), Springer.
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Background image: CC-A Ken Bosma.