Thomas Cooley, Turion Space; Yu-Yen Chang, Turion Space; Ryan Westerdahl, Turion Space; Tyler Pierce, Turion Space; Alexander Rogers, Turion Space
Keywords: Non-Earth-Imaging, Satellite Characterization, Sensor Calibration
Abstract:
With the recent ability to conduct non-Earth imaging (NEI) and capture satellite-to-satellite (Sat2) images under a NOAA commercial license, Turion has developed and launched two satellites specifically designed for Sat2 imaging. This capability represents a significant advancement in space-based imaging, allowing for direct observation of resident space objects (RSOs) from orbit and thus providing the ability to capture and analyze resolved EO images unconstrained to a single geographic location such as Maui, an unprecedented opportunity to enhance space domain awareness (SDA), refine satellite characterization techniques, and improve the overall security and management of space assets.
The task of acquiring high-quality Sat2 imagery is particularly challenging due to the high relative velocities between imaging and imaged satellites, especially for non-co-orbital objects. Imaging a fast-moving target from another moving platform in space requires precise control of a spacecraft and advanced processing techniques. This paper delineates the methodologies employed to overcome these challenges, as well as the broader implications of Sat2 imaging for SDA.
We present an analysis of datasets collected from Turion’s DROID.001 and DROID.002 missions, focusing on three core technical challenges: 1) photometric calibration of resolved targets, 2) extraction of metric observations from narrow field-of-view (NFOV) space-based imagers, and 3) risk assessment of RSO misidentification. Each of these aspects plays a critical role in ensuring that Sat2 imaging can be effectively utilized for operational and scientific purposes.
Photometric calibration is essential for deriving meaningful insights from space-based observations. The ability to accurately measure and interpret the brightness and reflectance characteristics of RSOs enables improved attitude determination, and activity monitoring. However, space-based imaging systems must contend with a variety of environmental factors, including stray light, thermal fluctuations, and sensor degradation. We examine methods for noise modeling and calibration, ensuring that photometric measurements maintain high fidelity across diverse imaging conditions.
Another key aspect of Sat2 imaging is the extraction of metric observations from NFOV imagers. Unlike ground-based observations, which rely on established astrometric reference frames, space-based imagers require precise onboard calibration and ephemeris accuracy to extract meaningful positional and motion data. We discuss the methodologies used to derive metric observations from these imaging systems. These approaches enable the accurate determination of an RSO’s position and movement, contributing to improved tracking and conjunction assessment.
A critical challenge in space-based imaging is the potential for RSO misidentification, which can have significant implications for space traffic management, security, and strategic decision-making. The accuracy of RSO identification is influenced by multiple factors, such as image resolution, viewing geometry, and background clutter. We analyze the conditions under which misidentifications can occur and explore mitigation strategies, including multi-frame analysis and Bayesian statistical methods to incorporate prior knowledge into our technical approach in order to reduce false positives and improve the reliability of Sat2 imaging data.
Beyond technical considerations, Sat2 imaging has broad applications in SDA, including search and reacquisition efforts, detection of anomalous behaviors, and identification of potential cases of camouflage, concealment, deception, and maneuver (CCDM). By leveraging high-resolution imagery and advanced analytical techniques, space operators can gain deeper insights into the operational status and intent of satellites, enhancing overall space security and decision-making processes.
This paper underscores the transformative potential of commercial Sat2 imaging for satellite characterization and SDA by addressing the key challenges associated with photometric calibration, metric observation extraction, and RSO misidentification. The insights gained from the DROID.001 and DROID.002 missions provide valuable lessons for future satellite imaging initiatives, paving the way for enhanced monitoring and protection of space assets and refining methodologies that will enable more robust and reliable space-based imaging.
Date of Conference: September 16-19, 2025
Track: Satellite Characterization