Back in October 2021, the excellent team behind Sondehub added several features to the map. They added launch site locations, grabbed from the official NOAA database. Clicking on a particular launch site allowed a user to generate a weeks worth of flight predictions based on the most recent GFS run. Cool!

The red lines on this prediction map of Oakland show the next 14 launches (7 days). As with any prediction of the future, the further out you go the worse the prediction.

Reverse predictions (pdf) were also added, for predicting where a radiosonde was launched from. This feature would have been very helpful when I was trying to find the Monterey Bay launch location.

Scrolling around the new map, I saw a launch site just east of Houston, Texas. I knew some people that lived in Houston, so I sent them a radiosonde receiving station. The hardware was almost identical to the Santa Cruz station, except that this station is entirely inside a home. No weatherproof case was needed, which is great because I didn't really want to figure ...

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Now that the pandemic has tapered off a bit, I took another short trip up to Inuvik, NWT. While I was up there, I visited the Environment Canada Weather Station, and participated in a radiosonde launch.

The big news out of Inuvik during this trip was that the road from the airport to the town has been paved! The road is much smoother, and I don't need to worry about windshield cracks every time a big truck passes.

Since my 2016 visit, the site has been upgraded with modern equipment. The old Electrolyser Corporation hydrogen generator was replaced with a Proton Hogen unit, all housed in a modern building with explosion-proof light switches, electrical outlets, etc.

I arrived just before the Midnight UTC launch, and Chris already had the balloon inflated and was working on the radiosonde transmitter. As I saw in Newfoundland, Canada has transitioned to the Graw DFM-09 radiosonde.

To my surprise, he actually let me release this radiosonde. This was my first radiosonde release, and it's very similar to a bursting HAB release. One interesting aspect of ...

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Just after setting up a remote receiving station in the hills above Santa Cruz for tracking radiosondes launched from Monterey Bay, I started noticing some weird stuff with the station. The station would detect a LMS6-403 radiosonde, but was unable to actually decode anything. The "jamming" signal was always on the same frequency of 400.259 MHz, and occurred daily around noon and midnight UTC.

I speculated that it might be radiosondes from Vandenberg Space Force Base, approximately 300 km (~180 miles) south of the receiver along the coast of California. Although it would be cool to receive those radiosondes, the purpose of this station was to track the Monterey Bay radiosondes, so I put that frequency on the blacklist and turned my attention to the task at hand.

New LMS6-403 Radiosonde Version

A few days later, my curiosity got the better of me, and I started to investigate these signals. Over the course of four days, I did decode a single packet each from two radiosondes. Based on the location, these definitely were from Vandenberg, but the signal must ...

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The SF-HAB group launched another picoballoon on December 11th, 2021, from the Berkeley Marina. The launch party was Martin W6MRR, Robert K6RGG, and Kazu AG6NS. This picoballoon used two clear Chinese party balloons with hydrogen gas for lift. Martin's custom electronics was used, with a WSPR transmitter that alternated 14 MHz (20 meters) and 10 MHz (30 meters).

The aprs.fi callsign was W6MRR-22 using the WSPR to APRS bridge, and the WSPR callsign was W6MRR.

This picoballoon floated between 9,900 and 11,100 meters (32.5k to 36.5k feet) for the duration of the flight, which is the perfect altitude for picoballoons. This is above most bad weather (rain and thunderstorms), but still low enough to be in the fast part of the jetstream.

From Oakland, this picoballoon headed east at a pretty fast clip. In total, it traveled about 23,000 km (~17,000 miles) in 12 days, for an average speed of about 80 km/hr (~50 MPH).

One interesting thing was that this balloon was not received on Dec 20th and 21st, when it ...

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While the previous Lodi picoballoon was floating over Mexico City, we launched another picoballoon from the southeast corner of the Berkeley Marina on November 13th, 2021. The launch party was Martin W6MRR, Robert K6RGG, Kazu AG6NS, and myself KF6ZEO.

The forecast for the morning was no wind, and when we arrived at 10am the winds felt pretty calm. But after assembling the picoballoon train, it was apparent that even the very light breeze was too strong. The two clear Chinese party balloons were bent over, threatening to scrape against the ground.

We waited almost 30 minutes for the winds to die down enough to release the picoballoon. During a bit of a lull in the wind, we walked across the parking lot while slowly releasing the balloon, kind of an in-motion release. This worked pretty well, and liftoff was at 10:30am local time (1830 UTC).

The tracker electronics were built by Martin W6MRR, and we used two clear Chinese party balloons with hydrogen for lift. The WSPR callsign was W6MRR, and the APRS callsign was W6MRR-21.

W6MRR-21 Flight Results ...

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SF-HAB's Central Valley Division launched a picoballoon from Lodi, California, on Thursday November 11th, 2021. The launch party was David WB6TOU and Skip N6NFB. The tracker electronics used this time was a ZachTek WSPR Pico transmitter. Two Chinese party balloons were used for lift.

The WSPR callsign for the balloon was N6NFB, and the APRS callsign was N6NFB-1.

N6NFB-1 Flight Results

Unfortunately, the tracker electronics did not power up on launch day, November 11th. We thought all was lost, but it awoke the next day in Maidenhead grid square DL58, which is ~1640 km (~885 mi) southeast of the launch location. The balloon was at an altitude between 9,900 and 11,100 meters (~32.4k to ~36.4k feet). Only 11 WSPR packets were received by the network on the second day.

In total, only 29 packets from this picoballoon were received by the WSPR network, indicating that something was wrong with the transmitter or antenna. This balloon transmitted for 3 days total.

The last packet received from this picoballoon on November 14th was in EL77, which is about ...

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I recently went on a work trip to Newfoundland, Canada. Checking Sondehub before I left, I saw that there were two radiosonde launching stations on the Island of Newfoundland, one on the west side in Stephenville, and the other on the far east end in St. John's. And as luck would have it, I was traveling to Lewisporte, which is on the Trans-Canada highway almost halfway between the two launching sites. I might be able to receive both sondes at the same time!

As far as I could tell, the radiosondes launched at both of these sites were Graw DFM-09P (pdf), which transmit around 403 MHz. One interesting thing about these radiosondes is that they don't transmit a serial number with every packet, so it takes a while to determine the serial number of the radiosonde you are receiving.

Receive Station

Since I was traveling, I needed a portable station with two receivers. This is very similar to my standard radiosonde receive station at home, and I didn't use a preamp or filter.

The Comet M-24M dual-band amateur radio antenna ...

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In the beginning of October 2021, we had a flurry of launches from the Berkeley Marina. In the span of two weeks, we launched five balloons. All of the picoballoons woke up after launch, which means that we are getting better at building, testing, and launching picoballoons. But unfortunately, only one of them survived the first night and woke up the next day. We can't achieve our goal of going around the world if the picoballoons only last for one day!

All of these picoballoons used the same custom electronics designed and built by Martin W6MRR. Two cheap Aliexpress 36-inch clear plastic balloons were used, with around 6 grams of free lift.

Picoballoon Launch 12: K6RGG-11

On Thursday, Sept 30th, we launched just after noon local time (1900 UTC). The launch party was Martin W6MRR and Robert K6RGG. The tracker turned on about an hour later at 2022 UTC.

This picoballoon was interesting because the tracker alternated transmitting WSPR beacons on 20 meters (14 MHz) and 30 meters (10 MHz). The antenna was the standard 20m dipole, not tuned for ...

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We launched again on Monday, September 20th, 2021, from our usual spot in the Berkeley Marina. The launch party was Martin W6MRR and Robert K6RGG, and the launch time was a bit later than usual at 11:30am Pacific time (1830 UTC). The picoballoon did not wake up on launch day. After our previous halfway around the world picoballoon, we were a bit dismayed to have another failed launch.

But the following day it woke up! The picoballoon was meandering out in the Pacific Ocean in gridsquare CL79, somewhere between 9,900 and 11,100 meters (32.5k to 36.5k feet). While this is higher than most of our previous picoballoons, our ideal altitude is above 11,100 meters, which is higher than most bad weather but still in the jetstream.

Something was definitely wrong with the tracker, because on Tuesday Sept 21st we only received a total of 7 packets from KFS and KPH (pdf). These two stations have have huge antennas right on the California coast near San Francisco, with excellent receivers. I ran a Hysplit prediction ...

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At the beginning of Week 3 of Launch 10, we were getting excited that this balloon might circumnavigate the globe. The prediction made from the middle of Egypt showed strong winds would take the balloon to the West Coast within 5 days, maybe even crossing the -122 degree longitude line of our launch site before heading back out to sea.

Flight Results

Unfortunately, the picoballoon only survived two more days in the Middle East. In a situation eerily similar to W6MRR-17, a single packet was received from the ground in southwest Uzbekistan near the Turkmenistan border. The altitude reported was less than 900 meters (encoded in the WSPR power field as 0 dBm or 1 mW). Maybe the tracker was stuck in a tree, or just laying on the ground, we will never know. The single packet from the ground was received by Jari Perkiömäki OH6BG in Finland, approximately 3,700 km away.

This picoballoon made it all the way from gridsquare CM87 to MN10. The center of MN10 is 63 degrees East longitude, which means that the balloon traveled ...

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