Orbital Predictor for Earth Observation - Introduction

This post is about an application I developed for my final year project (FYP), which I did as part of my Computer Science degree in University College Dublin  (UCD).

Overview and Features

Orbital Predictor is an web application which can be used to predict the orbits of one or more satellites, and then visualize those orbits, using the Cesium 3D globe. It can also make overpass predictions, by specifying an area of interest (AOI), the user can run a query to find out which satellites will pass over their AOI, during the time period they are interested in.
This returns a list of satellites, whose on-board instruments field of view will intersect the AOI during its orbit. These overpasses can then be visualized in Cesium.

The app is aimed at scientists looking to plan Earth observation campaigns, by allowing them to quickly find out which satellites will be in a position to make the required observations.

The list of satellites and information required to predict their orbits is sourced from Celestrak. This list can be updated by downloading different categories of satellites, depending on the type you are interested in.

The application also has a basic API, which allows you to run these queries from your own program, and be returned a CZML file for orbit prediction queries, or a JSON array for the overpass queries.
The CZML file can be used to visualize the satellites orbit in Cesium, while the JSON array contains values related to the satellites overpass, such as start time and duration.

Another feature is the ability to create your own satellite. This allows you to define a satellites name, its Two Line Element (TLE), its on-board instruments name, and its instruments swath width.
The TLE defines a satellites orbit, while the instrument swath width defines its field of view. You can then run queries against this new satellite like any other.

Finally you can register an email address, and the application keeps track of your previous queries, allowing you to run them again in the future. Registering is also required to update the satellite list or to create your own satellite.

Feedback

Feedback on Orbital Predictor has been fairly positive.
Cesium added it to their demos page, while Celestrak also added it to their Satellite Tracking Software Index page, both of which drives fairly steady traffic to the site.

That's it for now, this first post was just to introduce the application, but I will do more in the future, covering the following topics:

• How it was developed and the architecture employed
• The different features in more detail and some use cases
• Libraries and algorithms used to predict the orbits and overpasses, as well as the theory behind them
• Possible future features to be added

In the mean time you can head over to www.orbitalpredictor.com to check out it out, where you can also find more info on the About page.