How Does A Sail Drone Bring Home Hurricane Footage In Record Time?

October 5, 2021 by Ryan Flowers 11 Comments

It is unlikely that as a young lad [Richard Jenkins] would had have visions of sailing into the eye of a Category-4 hurricane. Yet that’s exactly what he’s done with the Explorer 1045, an uncrewed sailing vehicle built by his company, Saildrone. If that weren’t enough, footage from the vessel enduring greater than 120 MPH (almost 200 km/h) winds and 50 foot (15 M) waves was posted online the very next day, and you can see it below the break. We’re going to take a quick look at just two of the technologies that made this possible: Advanced sails and satellite communication. Both are visible on Explorer 1045’s sibling 1048 as seen below:

Saildrone Explorer 1048, a sibling of Explorer 1045, each one of five vessels equipped with a "hurricane wing" — Saildrone Explorer 1048, a sibling of Explorer 1045, each one of five vessels equipped with a “hurricane wing”

The most prominent feature of course is the lack of a traditional sail. You see, from 1999-2009, [Richard Jenkins] was focused on setting the land world speed record for a wind powered vehicle. He set that record at 126.1 mph by maturing existing sail wing technology. [Richard] did away with conventional rigging and added a boom with a control surface on it, much like the fuselage and empennage of a sailplane.

Instead of adjusting rigging, the control surface could be utilized to fly the wing into its optimal position while using very little energy. [Richard] has been able to apply this technology at his company, Saildrone. The 23 foot Explorer vessel and its big brothers are the result.

How is it that the world was treated to the view from inside the eye of a hurricane only a day after the video was recorded? If you look at the stern of the vessel, you can see a domed white cylinder. It is a satellite communication base station called the Thales VesseLINK. Thales is one of the partner companies that built the satellites for the Iridium NEXT fleet, which has 66 operational satellites in Low Earth Orbit. The Iridium Certus service uses its L-Band (1.6 GHz) signal to provide up to 352 kbps of upload speed and 704 kbps down. While not blazing fast, the service is available anywhere in the world and is reliable because it is not prone to rain fade and other weather based interference.

With just these two recent innovations, the Explorer 1045 was able to sail to the eye of a hurricane, record footage and gather data, and then ship it home just hours later. And we’re hardly exploring the tip of the iceberg. More than just sailboat based cameras, these scientific instruments are designed to survive some of the harshest environments on the planet for over a year at a time. They are a marvel of applied engineering, and we’re positive that there are some brilliant hacks hiding under that bright orange exterior.

If uncrewed sailing vessels float your boat, you might also enjoy this autonomous solar powered tugboat, or that time a submarine ran out of fuel and sailed home on bed sheets.

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L Band Satellite Antennas Revealed

August 4, 2019 by Al Williams 7 Comments

[SignalsEverywhere] has a lot of satellite antennas and he’s willing to show them off — inside and out — in his latest video that you can see below. Using software-defined radio techniques, you can use these antennas to pull off weather satellite images and other space signals.

A lot of these antennas are actually made for some commercial purpose like keeping ships connected to Inmarsat. In fact, the shipborne antenna has a nice motorized system for pointing the antenna that [SignalsEverywhere] is hoping to modify for his own purposes.

With what appears to be standard NEMA 17 steppers onboard, it should be relatively easy to supplant the original controller with an Arduino and CNC shield. Though considering the resale value these particular units seem to have on eBay, we might be inclined to just roll our own positioner.

The ~~QHF~~ QFH antenna is another interesting teardown. The antenna makes a helix shape and looks like it would be interesting to build from scratch. There isn’t a lot of details about the antenna designs, but it is interesting to see the variety and range of antennas and how they appear internally.

L band is from 1 GHz to 2 GHz, so signals and antennas get very strange at these frequencies. The wavelength of a 2GHz signal is only 15cm, so small antennas can work quite well and are often as much mechanical designs as electrical. The L band contains everything from GPS to phone calls to ADS-B.

We’ve seen radiosonde antennas reborn before. Dish antenna repurposing is also popular.

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Fallen Radiosonde Reborn As Active L-band Antenna

January 5, 2018 by Dan Maloney 14 Comments

If your hobby is chasing radiosondes across vast stretches of open country, and if you get good enough at it, you’ll eventually end up with a collection of the telemetry packages that once went up on weather balloons to record the conditions aloft. Once you’ve torn one or two down though, the novelty must wear off, which is where this radiosonde conversion to an active L-band antenna comes from.

As it happens, we recently discussed the details of radiosondes, so if you need a primer on these devices, check that out. But as Australian ham [Mark (VK5QI)] explains, radiosondes are a suite of weather instruments crammed into a lightweight package with a GPS receiver and a small transmitter. Lofted beneath a weather balloon into the stratosphere, a radiosonde transmits a wealth of data back to the ground before returning on a parachute after the balloon bursts. [Mark] had his eyes on the nice quadrifilar helical antenna used by the Vaisla R92 radiosonde’s GPS receiver, with the aim of repurposing them. He had a lot of components to remove while still retaining the low-noise amplifier (LNA), but in the end managed to get a working antenna with 40 dB gain in the L-band, and with the help of an RTL-SDR dongle he picked up solid signals from Iridium satellites.

Want to score your own radiosonde to play with? First, you have to know how to listen in so you can find them. Or, you know – there’s always eBay.

[via RTL-SDR.com]

An Antenna That Really Cooks–Really

June 19, 2017 by Al Williams 19 Comments

[9A4OV] set up a receiver using the HackRF board and an LNA that can receive the NOAA 19 satellite. Of course, a receiver needs an antenna, and he made one using a cooking pot. The antenna isn’t ideal – at least indoors – but it does work. He’s hoping to tweak it to get better reception. You can see videos of the antenna and the resulting reception, below.

The satellite is sending High-Resolution Picture Transmission (HRPT) data which provides a higher image quality than Automatic Picture Transmission (APT). APT is at 137 MHz, but HRPT is at 1698 MHz and typically requires a better receiver and antenna system.

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Junkyard Dish Mount Tracks Weather Satellites

January 2, 2017 by Dan Maloney 11 Comments

There’s a magnificent constellation of spacecraft in orbit around Earth right now, many sending useful data back down to the surface in the clear, ready to be exploited. Trouble is, it often takes specialized equipment that can be a real budget buster. But with a well-stocked scrap bin, a few strategic eBay purchases, and a little elbow grease, a powered azimuth-elevation satellite dish mount can become affordable.

The satellites of interest for [devnulling]’s efforts are NOAA’s Polar-orbiting Operational Environmental Satellites (POES), a system of low-Earth orbit weather birds. [devnulling] is particularly interested in direct reception of high-definition images from the satellites’ L-band downlink. The mount he came up with to track satellites during lengthy downloads is a tour de force of junkyard build skills.

The azimuth axis rotates on a rear wheel bearing from a Chevy, the elevation axis uses cheap pillow blocks, and the frame is welded from scrap angle iron and tubing. A NEMA-23 stepper with 15:1 gearhead rotates the azimuth while a 36″ linear actuator takes care of elevation. The mount has yet to be tested in the wind; we worry that sail area presented by the dish might cause problems. Here’s hoping the mount is as stout as it seems, and we’ll look forward to a follow-up.

It would work for us, but a 4-foot dish slewing around in the back yard might not be everyone’s taste in lawn appurtenances. If that’s you and you still want to get your weather data right from the source, try using an SDR dongle and chunk of wire.

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Portable Classroom Upgrade: Smaller, Cheaper, Faster

November 20, 2016 by Dan Maloney 7 Comments

[Eric] at MkMe Lab has a dream: to build a cheap, portable system that provides the electronic infrastructure needed to educate kids anywhere in the world. He’s been working on the system for quite a while, and has recently managed to shrink the suitcase-sized system down to a cheaper, smaller form-factor.

The last time we discussed [Eric]’s EduCase project was as part of his Hackaday Prize 2016 entry. There was a lot of skepticism from our readers on the goals of the project, but whatever you think of [Eric]’s motivation, the fact remains that the build is pretty cool. The previous version of the EduCase relied on a Ku-band downlink to receive content from Outernet, and as such needed to stuff a large antenna into the box. That dictated a case in the carry-on luggage size range. The current EduCase is a much slimmed-down affair that relies on an L-band link from the Inmarsat satellites, with a much smaller patch antenna. A low-noise amp and SDR receiver complete the downlink, and a Raspberry Pi provides the UI. [Eric]’s build is just a prototype at this point, but we’re looking forward to seeing everything stuffed into that small Pelican case.

Yes, Outernet is curated content, and so it’s not at all the same experience as the web. But for the right use case, this little package might just do the job. And with a BOM that rings up at $100, the price is right for experimenting.

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FTA Dish Used To Receive L-band Amateur Radio

May 21, 2012 by Mike Szczys 11 Comments

[David Prutchi] has an FTA (free-to-air) satellite dish. This means he can tune and watch freely available satellite television feeds. But this sounds much better than it actually is. There isn’t much that’s broadcasted unecrypted from satellites with the exception of a collection of religious channels. But he still uses the dish by using the FTA satellites to calibrate the alignment, then repositioning it to receive L-Band radio transmissions with his own add-on hardware. In the image above it’s the spiral of wire attached to the dish’s collector.

The satellite transmissions are picked up on the KU-band by an aftermarket horn that [David] purchased for this purpose. To add his own helix receiver he cut a square mounting plate that fits around the horn. This plate serves as a reflector and ground plane, and also hosts the helix connector which picks up the L-band transmissions. He had to be creative with routing the first few inches of the helix but it looks like he manages to get some pretty good performance out of the hardware.

[via Hacked Gadgets]