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  1. Two Months of Radiosonde Balloon Reception

    It's been two months since my first radiosonde recovery. In this post, I perform some analysis of the receiving stations at my apartment in San Francisco and my vacation home/parents place in Los Gatos. I also include the python code needed to generate your own plots.

    San Francisco Station

    Immediately after I got home from my first recovery, I converted my regular amateur radio station at my apartment to receive radiosondes. The external antenna is a Diamond X-50NA, which is a great amateur radio 5/8 wave 2m/70cm dual-band antenna. Coax up to the roof is about 80 ft of LMR-400, which is calculated at around 1.5 dB loss at 145 MHz and 2.5 dB at ...

  2. Two Radiosonde Payload Recoveries, and RS-41SGP Teardown

    I've been watching SondeHub for the past two months to, every day since my first recovery, but the winds have not been cooperating! Lots of radiosondes went into the hills east of San Jose, out into the ocean, into the Santa Cruz mountains, all the way down to Gilroy, or splashed down in the bay, but none have landed in populated areas within an hours drive of my home in San Francisco. I realized how lucky I was that the first radiosonde I successfully tracked actually landed in a populated place.

    In a typical city, approximately 35-50% of the land is dedicated to cars: residential roads, arterials, freeways, and parking lots. So when a balloon lands in populated areas of ...

  3. Oakland Radiosonde Investigation, Launch, and Recovery

    I've recently stumbled upon the radiosonde_auto_rx project. I've always been interested in tracking radiosondes, and even watched a radiosonde launch in Inuvik, NWT a few years back. Worldwide, there are over 800 launches every twelve hours of every day, and this data feeds into weather forecast models.

    The radiosonde_auto_rx project is built around decoding many different types of radiosondes with a software-defined receiver. The preferred receiver is a RTL-SDR Blog v3, and I already had an extra one of those (because they are so inexpensive!).

    Most radiosondes worldwide use 400-406 MHz as their downlink, but the United States also uses some frequencies around 1680 MHz. Reading the documentation on which frequencies are in use, it appeared that 1680 MHz was ...

  4. Radiosonde Launch from Inuvik, NWT

    In September 2016 I visited the Environment Canada Weather Station in Inuvik, NWT. I arrived just as they were preparing for the 2300z weather balloon launch, and they let me hang around and take some pictures.

    Every twelve hours around the globe, approximatley 800 radiosondes are launched. These weather balloons record temperature, pressure, humidity, and location from the surface all the way up to 100k feet, or higher. These measurement are fed into weather models for long-term weather forecasting. These launches happen worldwide at 1100 and 2300 UTC, which gives the balloon enough time to be up at altitude around noon and midnight UTC.

    This is the Vaisala RS92-SGPD radiosonde, which measures location, pressure, temperature, and humidity as the balloon ...

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