Comparison of BRDF-Predicted and Observed Light Curves of GEO Satellites

Abstract

Although the amount of light received by sensors on the ground from Resident Space Objects (RSOs) in geostationary orbit (GEO) is small, information can still be extracted in the form of light curves (temporal brightness or apparent magnitude). Previous research has shown promising results in determining RSO characteristics such as shape, size, reflectivity, and attitude by processing simulated light curve data with various estimation algorithms. These simulated light curves have been produced using one of several existing analytic Bidirectional Reflectance Distribution Function (BRDF) models. These BRDF models have generally come from researchers in computer graphics and machine vision and have not been shown to be realistic for telescope observations of RSOs in GEO. While BRDFs have been used for SSA analysis and characterization, there is a lack of research on the validation of BRDFs with regards to real data. In this paper, we compared telescope data provided by the Air Force Research Laboratory (AFRL) with predicted light curves from the Ashikhmin-Premoze BRDF and two additional popular illumination models, Ashikhmin-Shirley and Cook-Torrance. We computed predicted light curves based on two line mean elements (TLEs), shape model, attitude profile, observing ground station location, observation time and BRDF. The predicted light curves were then compared with AFRL telescope data. The selected BRDFS provided accurate apparent magnitude trends and behavior, but uncertainties due to lack of attitude information and deficiencies in our satellite model prevented us from obtaining a better match to the real data. The current findings present a foundation for ample future research.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Oct 18, 2015
Accession Number
AD1001954

Entities

People

  • Angelica Ceniceros
  • David E. Gaylor
  • Elfego Iii Pinon
  • Jessica Anderson
  • Phan Dao
  • Richard Rast

Organizations

  • University of Arizona

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Artificial Satellites
  • Celestial Brightness
  • Data Sets
  • Geosynchronous Orbits
  • Geosynchronous Satellites
  • Reflectance
  • Reflection
  • Simulations
  • Solar Panels
  • Space Objects
  • Space Surveillance
  • Space Systems
  • Spacecraft
  • Specular Reflection
  • Time Intervals

Readers

  • Computational Modeling and Simulation
  • Space Exploration and Orbital Mechanics.
  • Spectroscopy.

Technology Areas

  • Space
  • Space - Space Objects