Tag Archives: orbital debris

Lecture 2 – Orbital Mechanics Review A

If you haven’t already signed up; please submit your email to receive notifications and updates about the course.

[contact-form][contact-field label=”Email” type=”email” required=”1″ /][/contact-form]

Lecture

We review orbital mechanics and Newton’s law of gravitation to prepare for orbit determination. We will cover the two body problem, orbital elements, and perturbing accelerations. We won’t finish the entire lecture today. We will continue on Monday.

[youtube https://www.youtube.com/watch?v=eBekNtOqy-k]

Previous Lectures

Lecture 1

Resources

Lecture 2 – Orbital Mechanics Review A

Lecture 1 – Orbit Determination Concepts (slides)

AppendixA-ProbabilityAndStatistics

Lecture 1 – Orbit Determination Concepts

If you wish to receive class updates and announcements please submit your email here!

[contact-form][contact-field label=”Email” type=”email” required=”1″ /][/contact-form]

Lecture

The inherent characteristics of an orbit determination (OD) problem are introduced. Dynamic state estimation, observations, linearization, and the state transition matrix are discussed. At the end, I have left a practice problem that we will review on Friday, 8 June. We throw a satellite up and watch it come down while introducing some important concepts.

[youtube https://www.youtube.com/watch?v=0g0QzppL1Ow]

Resources

Lecture 1 – Orbit Determination Concepts (slides)

AppendixA-ProbabilityAndStatistics

Statistical Orbit Determination

If you wish to receive class updates and announcements please submit your email here!

[contact-form][contact-field label=”Email” type=”email” required=”1″ /][/contact-form]

Class time/Preliminary Notes

I will be teaching a statistical orbit determination course this summer. This will be on my own time. All lectures will be posted to YouTube. I will be teaching the course out of Bob Schutz’s, Byron Tapley’s, and George H. Born’s, Statistical Orbit Determination. Feel free to use any textbook you desire but the problems and solutions will be assigned from this text. I have included some precursor notes in question and answer format on statistics and probability below.

AppendixA-ProbabilityAndStatistics

Syllabus

AEM_StatisticalOrbitDetermination_Syllabus_CRS

STATISTICAL ORBIT DETERMINATION

EXECUTIVE SUMMARY:

Orbit Determination (OD) is the problem of determining the best estimate of the state of a spacecraft whose initial state is unknown, from observations influenced by random and systematic errors, using a mathematical model that is not exact. Mordern OD is used to support all space missions from JSpOC’s observations of artificial Earth satellites to the International Space Station’s trajectory planning incorporating elements of probability, statistics, and matrix theory. A special projects class is needed to cover this vital part of the space curriculum that arguably makes the backbone of any space program.

DISCUSSION:

Modern OD approaches have been developed by the NASA Jet Propulsion Laboratory (JPL) to fulfill Earth and planetary navigation requirements and at the NASA Goddard Space Flight Center (GSFC) and the Department of Defense Naval Surface Weapons Center in applications of satellite tracking to problems in geodesy, geodynamics, and oceanography. The Joint Space Operations Center (JSpOC) at Vandenberg Air Force Base, the Conjunction Assessment Risk Analysis (CARA) at GSFC, and Trajectory Operation Officers (TOPO) at Johnson Space Center (JSC) use modern OD techniques in applications of satellite tracking, conjunction assessment, and protecting vital assets from the International Space Station to the National Reconnaissance Office (NRO) spy satellites.

Clearly, OD is an important part of any space mission. The proposed class will use the classical text, Statistical Orbit Determination, by Drs. Byron Tapley, Bob Schutz, and George Born. This basic OD course will cover:

  • Introduction to OD problem
    • Dynamic system and associated state
    • Observations are non-linear functions of state variables
    • Classical well-determined approach
    • Modern over-determined approach
  • Observations to measure satellite motion
    • Ground-based systems: laser, radiometric, etc.
    • Space-based systems: GPS, etc.
    • Error sources and media corrections
  • Non-linear OD reduced to linear state estimation
    • Application of linear system theory
    • Incorporation of algorithms to computational environment
    • Sequential processing of observations
    • Control of real-time processes

This will be supported by background and supplemental information in:

  • Probability and Statistics
  • Review of Matrix Concepts
  • Examples of State Noise and Dynamic Model Compensation
  • Solution of the Linearized Equations of Motion

Students can expect to incorporate their classroom knowledge into real-life by building optical and radiometric sensors supporting The University of Alabama’s new satellite ground station.

LECTURES:

Lecture 1 – Orbit Determination Concepts

Lecture 2 – Orbital Mechanics Review

CODER 2016: Panelist/Presentation/Experience

I presented Tuesday at the Center for Orbital Debris Education and Research on “CubeSat Network for Prediction and Tracking of Orbital Debris.” The key points:

  1. Conceptual Stage of Development
  2. LIDAR ~700W and CubeSat ~200 W
  3. Assuming UV laser, 355 nm, resolution of 1 mm would require a 2 m telescope diameter for a range of 5 km

Presentation is attached here: simpson_v2

Several topics that are of interest specifically to my presentation:

  • Research that suggests that the satellite operators that do not follow good practices will be the primary source of new collisions in the future. Roger Thompson, The Aerospace Corporation, spoke to this on my panel.
  • Space is about to get a lot more crowded. To put it in context their have been 56 launches this year. SpaceX filed for 4400 satellites with the FCC Wednesday.
  • There is a strong need for knowledge of conjunctions and good covariance analysis. I.E. there seems to be the need for secondary analysis for conjunction warnings from JSpOC. On my panel Don Greiman, Schafer Commercial Space Situational Awareness Team, spoke to this from the commercial side and Ryan Shepperd as analysis in-house for Iridium.

Talk about a huge learning experience. I hope to take what I’ve learned back to The University of Alabama and disseminate this knowledge among our academic community. I also plan to stay in touch with the contacts I’ve made to help expand my horizons.

Presenter for CODER 2016 Workshop

CODER is the Center for Orbital Debris for Education and Research. CODER is having a Workshop and accepted our, Dr. O’Neill and I, abstract for CubeSat Network for Orbital Debris Tracking and Prediction. I will be a presenter for the Space Situational Awareness Session. Here’s the link for my session and bio: CODER 2016 Sessions

The conference is hosted at the University of Maryland on November 15-17. If you’re headed to the conference hope to see you there!