Over on YouTube Manuel from the 'Build a Cubesat' channel has uploaded a video testing a prototype version of our Discovery Drive antenna rotator. If you are unaware, Discovery Drive is our new antenna rotator product for applications like satellite tracking and general antenna positioning that is currently being crowd-funded over on Crowd Supply. There are two days left in the campaign.
In the video, Manuel overviews the Discovery Drive, shows the internals, and walks us through the web UI. He goes on to show how it can be set up with the SatNOGS project. The SatNOGS project has volunteers set up ground-based satellite stations, and anyone can use those stations to log an observation anywhere in the world.
We note that he mentioned some trouble with getting SatNOGS to rotate the Discovery Drive over zenith. We have added a note to our Wiki showing how this can be fixed by specifying the correct rotational limits for the Discovery Drive.
Over on YouTube, Gabe from the saveitforparts channel has uploaded a new video testing a prototype of our upcoming Discovery Drive Az/El antenna rotator, which is now live for crowdfunding on Crowd Supply.
In the video, Gabe unboxes the Discovery Drive and sets it up with a Discovery Dish. He then tests it on various weather satellites, including Meteor M2-4, Meteor M2-3, DMSP, Metop-B, and Metop-C. Later in the video, Gabe shows that you can also attach an Arrow Yagi antenna to the mount and notes that in a future video, he hopes to test CubeSat and Amateur radio satellite reception with the Yagi.
We're extremely pleased to announce that our campaign for our Discovery Drive automatic antenna rotator is now live on Crowd Supply! Pricing is reduced during the campaign period, so check it out soon!
Discovery Drive is an automatic antenna rotator designed for use with our Discovery Dish product, as well as similarly sized antennas such as Wi-Fi grid and Yagi antennas.
A motorized rotator, such as Discovery Drive, enables precise tracking of fast-moving polar orbiting satellites using a satellite dish or directional antenna. Examples of polar orbiting weather satellites include METEOR-M2, METOP, and FENGYUN. Depending on your location, you may also have access to other interesting satellites that dump data over specific regions.
In addition to public weather data, operators and enthusiasts might be interested in using Discovery Drive to track CubeSats, and amateur radio operators may wish to track amateur radio satellites.
Amateur radio astronomy hobbyists can map the galaxy in the hydrogen line spectrum using Stellarium, or custom software to aim a Discovery Dish with H-Line feed, allowing you to scan multiple parts of the sky in one night.
Discovery Drive - A Motorized Antenna Rotator Engineered for Discovery Dish
Thank you to Alex P for writing in and sharing with us his detailed evaluation of the Discovery Dish 1420 MHz hydrogen line feed when paired with a low-cost 1m WiFi grid dish. The goal was to see how well this near off-the-shelf setup performs as a hydrogen line radio telescope. The Discovery Dish feed integrates the dipole very close to the internal LNA and filters to minimize losses, uses a weather-sealed enclosure, and is built around a low-noise Qorvo QPL9547 amplifier, which has a very low noise figure at 1420 MHz.
Alex used 4NEC2 with a simple geometry approximation to analyze the beam pattern and also experimentally determined the optimal feed-to-dish spacing for the WiFi grid. The results show that the Discovery Dish feed significantly outperformed a more standard feed + external LNA setup.
Alex also shows how he uses aluminum foil, or conductive foam, to shield the feed from all signals during a background correction scan. Generally, for background correction scans, we recommend pointing towards a cold area of the sky (any area far away from the Milky Way with little to no hydrogen), but Alex prefers this method.
Discovery Dish 1420 MHz Hydrogen Line Feed Tested on a WiFi Grid Dish
Over on YouTube Matt from the Tech Minds YouTube channel has recently uploaded a new video where he tests out our Discovery Dish antenna. Discovery Dish is designed to be a low-cost, portable solution for receiving L-band and S-band weather satellites, Inmarsat satellites, conducting amateur hydrogen line radio astronomy, and more.
In the video, Matt unboxes the Discovery Dish and provides an overview of the build process before demonstrating its use in decoding AERO and STD-C messages on Inmarsat. He then shows the dish and Inmarsat feed being used to receive Iridium satellites, and how they can be decoded using iridium-extractor with a HackRF or Airspy R2.
Finally, Matt swaps out the Inmarsat feed for the Hydrogen Line feed. Using SDR#, the IF AVG plugin, and Stellarium, he was able to obtain a clear hydrogen line peak.
This Discovery Dish Is The ONLY Satellite Dish You Will Need!
Discovery Drive is an automatic antenna rotator that is designed to be used with our Discovery Dish product, as well as similarly sized antennas such as Wi-Fi grid and Yagi antennas.
Discovery Drive with Discovery Dish Mounted
A motorized rotator allows you to use a satellite dish or directional antenna to track and receive signals from polar orbiting satellites, which quickly move across the sky. It also lets you switch swiftly between geostationary satellites without manually realigning the dish.
Examples of polar-orbiting weather satellites that you can track include NOAA POES, METEOR-M2, METOP, and FENGYUN. Depending on your location, you may also have access to other interesting satellites that dump data over specific regions. Amateur radio operators can also use Discovery Drive to track amateur radio satellites with Yagi antennas.
Discovery Drive
Discovery Dish is designed to be easy to set up and use. Unlike many other rotators on the market, no external controllers are required. Discovery Drive has a built-in ESP32 controller, and control can be commanded over WiFi or serial from rotctl-compatible software such as SatDump, GPredict, and Look4Sat on Android.
Features and Specifications
Up to 125 kgcm (12.25 Nm) of torque
ESP32 control board
± 1.5° of accuracy
-360° to +360° Azimuth range, 0° - 90° elevation range
1.5 RPM Azimuth speed, 0.25 RPM elevation speed
12 V power input (either barrel jack or USB Type-C Power Delivery)
Wi-Fi connectivity with browser-based web UI
Serial over USB data connectivity or Wi-Fi data connectivity
Low power draw (< 10 W, can be powered with PoE+ supplies and still have power left over for powering a single board computer and RTL-SDR)
Robust worm gear-locked output drives
Direct rotctl compatibility over Wi-Fi (compatible with programs that implement the rotctl protocol, such as SatDump, GPredict, and Look4Sat on Android)
Electrical engineering magazine IEEE Spectrum has recently posted an article about our Discovery Dish product, which was successfully crowd-funded on CrowdSupply and delivered to initial backers early this year. Discovery Dish is a 70-cm aluminum satellite dish with an active filtered feed. It is designed for receiving real-time weather data from GOES HRIT, GK-2A LRIT, FengYun LRIT, NOAA HRPT, Metop HRPT, Meteor M2 HRPT, and other weather satellites that operate around 1.69 GHz. There are also feeds for Inmarsat satellites, Hydroden Line observation, and S-band satellites.
In the article, Stephen Cass introduces the Discovery Dish, highlighting its practical uses and the convenience of disassembling it for easy packing in a suitcase during travel. He also shares his experience using the Discovery Dish to successfully receive images from the GOES-East satellite from the rooftop of his New York City apartment.
Finally, he mentions how he tested the hydrogen line feed as well, successfully seeing a hydrogen line peak when pointing at the galaxy.
Image from the IEEE Spectrum Article on Discovery Dish
Over on the Airframes Community forum, user 'thebaldgeek' has posted a review of our Discovery Dish product. If you weren't already aware, the Discovery Dish is an easy-to-set-up and use backyard dish system for weather satellites, Inmarsat, and Hydrogen line radio astronomy.
In his post, thebaldgeek unboxes the dish and feed boxes, showing all the individual parts. He goes on to bolt the dish together and show it fully built. In the rest of the post, he compares the Discovery Dish with Inmarsat feed against three other options, including a GPS puck, our RTL-SDR Blog Active Patch Antenna, and a homemade 7-turn helix antenna.
As expected, the Discovery Dish performs the best, with the 7-turn helix coming in second, followed by the RTL-SDR Blog Patch, and finally, the GPS patch. He rightly notes that the dish does have increased wind loading over the other options, and this needs to be taken into account when positioning and mounting.
