Title: Constellation Operations and Instrument Analysis for Earth Science Missions using TAT-C
Presenting Author: Sreeja Nag
Organization: Bay Area Environmental Research Institute
Co-Author(s): Jon Verville, Phil Dabney (GSFC), Prachi Dutta (Texas A&M), Paul Grogan (Stevens), Joseph Gurganus (GSFC), Daniel Selva (Texas A&M), Pau Garcia Buzzi (Texas A&M), Steve Hughes (GSFC), Eric Magliarditi (MIT), Vinay Ravindra (BAER), Afreen Siddiqi (MIT), Michael Stark (GSFC), Jon Verville (GSFC)

The Tradespace Analysis Tool for Constellations (TAT-C) is a systems architecture analysis platform for pre-phase A Earth science missions with distributed spacecraft. It allows users to specify high-level mission objectives and constraints and efficiently evaluate large tradespaces of alternative architectures varying the number of satellites, orbital geometries, instrument assignments, and ground processing networks. Outputs characterize composite instrument coverage and performance, size and sequence launch manifests, and provide relative evaluations of cost and risk suitable for concept selection. This presentation discusses some of the recent TAT-C advances including a modular software architecture with interfaces suitable for extension, instrument models, and advanced search strategies leveraging machine learning to incorporate domain- and mission-specific knowledge in search execution. In particular, the TAT-C instrument module analyzes primary science instruments such as radar, pushbroom, and matrix imagers. A modular software architecture allows crisp interface definitions between user-defined or internal variables and payload variables. The instrument module provides feedback about payload-dependent differences among thousands of constellation architectures using key performance metrics such as revisit time of the sensor swath, differential signal to noise ratio (SNR), and spatial resolution of measurements to inform concept selection for more detailed development. The instrument module also informs operational decisions of satellite modes based on ground optimization or onboard autonomy. Incorporating performance evaluation from the instrument module and other software components, TAT-C aims to enable mission designers to consider a wider set of architectures leveraging constellations of small satellites in a diverse set of orbital geometries to achieve scientific objectives.