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.
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
The Wow! signal is a famous, strong, and unexplained radio signal detected in 1977 by the Big Ear radio telescope in Ohio, lasting 72 seconds and appearing to originate from the constellation Sagittarius. Its origin remains unknown, with some speculating that it could be an extraterrestrial technosignature. Upon reviewing the signal data, Astronomer Jerry R. Ehman discovered the powerful signal burst in the readout and wrote a large "Wow!" next to it, unintentionally coining the name.
A network of small radio telescopes offers several distinct advantages compared to large professional observatories. These systems are low-cost and can operate autonomously around the clock, making them ideal for continuous monitoring of transient events or long-duration signals that professional telescopes cannot commit to observing full-time.
Their geographic distribution enables global sky coverage and coordinated observations across different time zones, which is especially valuable for validating repeating or time-variable signals. Coincidence detection across multiple stations helps reject local radio frequency interference (RFI), increasing confidence in true astrophysical or technosignature transient events.
These networks are also highly scalable, resilient to single-point failures, and capable of rapid response to external alerts. Furthermore, they are cost-effective, engaging, and accessible, ideal for education, citizen science, and expanding participation in radio astronomy.
However, these systems also come with notable limitations when compared to professional telescopes. They have significantly lower sensitivity, limiting their ability to detect faint or distant sources. Their angular resolution is poor due to smaller dish sizes and wide beamwidths, making precise source localization difficult.
Calibration can be inconsistent across stations, and frequency stability or dynamic range may not match the performance of professional-grade equipment. Additionally, without standardized equipment and protocols, data quality and interoperability can vary across the network.
Despite these constraints, when thoughtfully coordinated, such networks can provide valuable complementary observations to professional facilities.
The team note that the Wow! signal was strong enough that it could have been detected by a small home radio telescope. They go on to make the case that we could be missing out on detecting many compelling signals simply because radio telescopes aren't watching every part of the sky simultaneously.
The project will monitor the Hydrogen Line frequency for interesting signals. Currently, the team is using a WiFi grid dish and an external LNA as the radio telescope hardware, but they also aim to evaluate our Discovery Dish with H-Line feed.
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.
SatDump is a popular program used to receive and decode images and other data from various weather satellites. SatDump works great RTL-SDR Blog dongles and with our Discovery Dish, an easy-to-use dish and feed for receiving L-band and other weather satellites. Recently SatDump version 1.2.1 was released, which brings several new features including:
Meteor-M Calibration - Temperatures and radiances are now available from the Meteor-M infrared channels, including enhancements like Cloud Top IR.
Archive Loader & EUMETSAT Archives (and EUMETCAST) Support: Metop, Meteosat, Sentinel-3 and more! - Users can now open data from the EUMETSAT archives in SatDump.
Windows ARM64 Support - One of the few SDR programs that has Windows ARM64 support.
JUICE Support - JUICE (JUpiter ICy moons Explorer) is an ESA probe tasked to study three of the Galilean moons of Jupiter, namely Ganymede, Callisto and Europa. During a recent Earth slingshot it was possible to receive.
AIRS and CERES Support - Hyperspectral sounder and radiation budget instruments on the Aqua satellite
Arctic Weather Satellite Support - AWS is a weather satellite recently launched in July 2024 with 1707 MHz downlink and similar parameters to METOP, so it should be accessible to many.
IASI (imaging channel) Calibration - Calibration for the hyperspectral sounder onboard METOP satellites.
GOES-R L2 Product Support - Pre-processed models from NOAA that include Rain Rate per Quarter Hour, Land Surface Temperature, Sea Surface Temperature, and more.
GOME Fixes - True Color for METOP satellites.
Miscellaneous AVHRR and MHS Fixes - Calibration stripes and other strangeness is less likely to occur even with a bad signal.
Miscellaneous Composites - Many new composites are available.
