Amateur Satellite Tracking System

Preface

I was amazed how other hams worked with Amateur Satellites and I imagined it needed tons of expertise and expensive equipment. To my surprise, that was not the case. I was able to grasp the basics very quickly by trying and failing. It is funny how every failure renewed my hope of success. Once I realized that it was I who was making the mistakes, fixing that was quite easy.

Here is a short sample video that captured the finished project being tested for Azimuth and Elevation movement.

And a video recording while tracking the amateur satellite AO-27 on Feb 5 2012. You'll notice I had to manually adjust the handheld radio to compensate for Doppler effect.

Introduction

The aim of this project is to build an Tracking System to track Amateur Satellites and have lots of fun building it, without being a drain on the finances. It involves a bit of everything from installing software, learning protocols, programming, soldering wires, making small plastic parts, and using small commonly available tools. Obviously, the satellite tracking system comprises of several subsystems. These are briefly highlighted in the following paragraphs and each one of them is described in much more detail in a separate page of its own.

Functional Block Diagram

To make it even more interesting, the inter-dependencies between these subsystems have been minimized so that you may easily modify a subsystem to match the parts you may already have, or experiment new ways of building it without affecting the rest.

The Satellite Tracking Program

The role of the tracking program is to compute the accurate position of the satellite of interest, in relation to the stationary observer on the ground. This program usually runs on a small Personal Computer like a laptop, etc. and provides Azimuth and Elevation coordinates to the tracking controller. It also timely updates based on the rate of movement of the satellite. More about setting it up and configuring it on the details page.

The Satellite Tracker Controller Communication Protocol

The communication protocol defines the syntax of all commands sent by the tracking program and status messages received from the tracking controller. More information ,examples and links to internet resources can be found on the details page.

The Satellite Tracker Controller

The tracking controller is a smart micro controller, like an Arduino, that receives positioning and other commands from the tracking program. It reacts to these commands by driving the head unit to position the antenna accordingly. It also responds back to the tracking program with status messages. Details on how to work with the Arduino board, making connections and programming are all provided here.

The Satellite Tracker Head Unit Interface

The head unit interface is just a set of electrical connections necessary to provide power and control signals to the head unit. Some of this will be evident from the tracker controller page, however electrical wiring diagrams provided on the more details page may help understand it a little better.

The Satellite Tracker Head Unit

The head unit is typically a electro-mechanical assembly that responds to signals from the tracking controller and tries to position itself as quickly and accurately as possible. It also provides a place to mount the antenna assembly. To build one yourself, please visit this page.

The Satellite Antenna Mount

The antenna mount is just a set of simple mechanical parts that help mount the satellite antenna(s) securely on the head unit. See how it works, and pictures here at the details page.

The Satellite Antenna

The satellite antenna is the payload that the entire system will help position in the direction of the satellite being tracked. The key to the success of the entire tracking system is that antenna be light enough as not to overwhelm the system. There is much to learn and understand here, but the best way is to just do it and worry later. Details here.

References:

Many thanks are due to a several internet and other resources that helped me learn and understand everything, so I could simply put the pieces together. I have listed the references that I studied, under each section.

Disclaimer & Legalities: (Keeping it safe for everyone)

At the time of the building of this system, no other similar systems were found through extensive search, nor was this system a copy of or derived from a similar system for tracking amateur satellites. This system has been the direct result of several lead-in projects, the results of which, when combined together have yield a simple yet flexible design.

Additionally, this system was conceived and developed for tracking amateur satellites, for the purpose of experimenting satellite communication within the scope of the amateur licence. The system was designed to be accurate within one angular degree, when used in non-hostile environments. Achieving better accuracy that may be required for other applications, may require more work beyond the scope of this project.

This website and the associated artifacts are original to the best of my knowledge and are being published for the express purpose of sharing ideas in the amateur radio community as well as for educational purposes if so desired. Commercialization of the concepts and/or artifacts published here is not encouraged. No part of this website may be reproduced, or plagiarized without the written consent of the author.

Comments and/or suggestions, and/or alternate ideas may be freely submitted to the author for consideration. Such items if considered for inclusion in the website shall be done with credit to the submitter. However, the submitter or their representatives shall not have further legal or commercial rights whatsoever, in regard to their submissions.