Wall-Mounted Ground Station Tames Unruly SatNOGS Node

For many of us, ad hoc projects end up having a certain permanence to them. Think of the number of Raspberry Pis and RTL-SDRs that are just dangling from a USB cable under a desk or stuffed behind a monitor, quietly going about their business. If it ain’t broke, don’t fix it.

Some projects, though, just end up accreting past the acceptable point. This wall-mounted SatNOGS ground station is a great example of what happens when something needs to be done about the mess. The pile of stuff that [cshields] had cobbled together over time for his ground station needed tidying, so he laid hands on a new Pi 4 and a cool enclosure/breadboard called a Stegoboard. This is just a piece of acrylic with a variety of holes laid out to match every imaginable PC board, hard drive, PC motherboard, Arduino, and just about anything out there that needs mounting. To contain the mess, he mounted the Pi and a 7″ touchscreen to the Stegoboard, along with an RTL-SDR and an Arduino to control his antenna rotator. The ground station wiring is still a little rough, but worlds better than what it was, and now that it’s mounted on the wall it’ll be much easier to use.

For those not familiar with SatNOGS, check out our article back from when the Satellite Network of Ground Stations won the 2014 Hackaday Prize. In the half-decade since then, SatNOGS has only grown, with a huge following of dedicated enthusiasts pointing their antennas at the sky. We know how to pick ’em, and we’ll be selecting the 2019 Hackaday Prize winner very soon.

Thanks to [elkos] for the tip.

Hackaday Prize Entry: Reverse GPS

Every time you watch a SpaceX livestream to see a roaring success or fireball on a barge (pick your poison), you probably see a few cubesats go up. Everytime you watch a Soyuz launch that is inexplicably on liveleak.com before anywhere else, you’re seeing a few cubesats go up. There are now hundreds of these 10 cm satellites in orbit, and SatNogs, the winner of the Hackaday Prize a two years ago, gives all these cubesats a global network of ground stations.

There is one significant problem with a global network of satellite tracking ground stations: you need to know the orbit of all these cubesats. This, as with all Low Earth Orbit deployments that do not have thrusters and rarely have attitude control, is a problem. These cubesats are tumbling through the rarefied atmosphere, leading to orbits that are unpredictable over several months.

[hornig] is working on a solution to the problem of tracking hundreds of cubesats that is, simply, reverse GPS. Instead of using multiple satellites to determine a position on Earth, this system is using multiple receiving stations on Earth’s surface to determine the orbit of a satellite.

The hardware for [hornig]’s Distributed Ground Station Network is as simple as you would expect. It’s just an RTL-SDR TV tuner USB dongle, a few antennas, a GPS receiver, and a Raspberry Pi connected to the Internet. This device needs to be simple; unlike SatNogs, where single base station in the middle of nowhere can still receive data from cubesats, this system needs multiple receivers all within the view of a satellite.

The modern system of GPS satellites is one of the greatest technological achievements of all time. Not only did the US need to put highly accurate clocks in orbit, the designers of the system needed to take into account relativistic effects. Doing GPS in reverse – determining the orbit of satellites on the ground – is likewise a very impressive project, and something that is certainly a contender for this year’s Hackaday Prize.

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Hacklet 34 – Satellite Projects

Space. The final frontier. Every tinkerer, hacker, and maker has dreamed of flying out of Earth’s atmosphere and into the heavens. Last year one hard-working team got a chance to fly a member to space by winning the Hackaday prize. For the rest of us, we can still experience some of that excitement by contacting satellites in orbit, or even sending a bit of our own hardware into space. This week’s Hacklet focuses on the best satellite projects on Hackaday.io!

basicSatWe start with [movax] and Your satellite devkit and launch. Chipsat is a tiny satellite which runs BASIC code. Yes, BASIC in space! Chipsats will be stacked into a launcher and sent off into space in groups. The idea is to eventually have them launched from the International Space Station. Power is provided by a small solar cell which charges up a pair of super capacitors. When the capacitors are charged, the satellite will run for a few seconds. Connectivity with the ground is via a 433 MHz link. Chipsat doesn’t just float in space, three coils give it the ability to control its attitude and rotation. Chipsat will sense the space around it with a magnetometer and a light sensor.

 

satnogsv2

No satellite-themed Hacklet would be complete without [Pierros Papadeas] and his team’s work on SatNOGS – Global Network of Ground Stations. SatNOGS aims to create a global network of connected satellite ground stations. Think of it as a grass-roots version of NASA’s deep space network for satellites in earth orbit. This is more than just a great idea, as SatNOGS won the 2014 Hackaday Prize. You can check out our coverage of the project back in November, 2014. Since then, the SatNOGS team has been busy! They’ve just deployed the first SatNOGS V2 system above their hackerspace in Athens, Greece.

trsiNext up is TRSI PocketQub Satellite, another project by [movax]. TRSI is a satellite that sends data via images which can be viewed with a simple RTL-SDR stick using Hellschreiber mode. Hell mode means that images can be directly viewed in the waterfall display of whichever SDR application is running the receiver. Numbers or entire images snapped with TRSI’s cell phone style camera module can be encoded and displayed. Power is of course provided by solar cells, and the communications link will be on the coordinated 433 MHz band. The original TRSI hardware has actually morphed into a deployment machine for ChipSat, [morvax’s] other satellite project. He’s put the main TRSI program on hold until after the ChipSat campaign is complete.

pocketquRounding out our satellite special is [OzQube] with his project QubeCast Max. QubeCast is the first Australian version of the PocketQube PQ60 satellite form factor. After watching the success of $50Sat project, [OzQube] wanted to design a satellite of his own. Since he wanted to add sensors and send more data back to Earth than previous efforts, he needed a higher data rate than the current crop of satellites. This meant going to a high-powered radio. To achieve this, he’s using a  NiceRF RF4463F30 radio module. The module is based upon a Silicon Labs Si4463 RF ISM band chip, coupled with a power amplifier. The module outputs 1 watt, which is quite a bit of power for a tiny satellite!

Want more satellite goodness? Check out Hackaday.io’s freshly minted Satellite List.

The countdown is almost at 0, so that’s just about all the time we have for this episode of the Hacklet. See you next week.  Same hack time, same hack channel, bringing you the best of Hackaday.io!