Intro to ADS-B weather

I last visited Oshkosh in 2010 where I started taking an interest in ADS-B. If you're new to that acronym, you can read all about it here. The prospect of having to spend money on a new piece of equipment (ADS-B out) didn't excite me much, but that won't be required until 2020 anyway. ADS-B in, on the other hand, I found intriguing, particularly after another flight across the country with periodic calls to flight watch asking for a verbal description of weather ahead. That's because a subset of ADS-B in, FIS-B, allows pilots to receive weather data in the cockpit. This post discusses my experiences with FIS-B using portable electronics to receive and display weather information.

Weather in the cockpit has been available for some time through XM satellite data subscriptions, billed at a monthly fee. FIS-B in is free (more precisely, we're paying for it through FAA funding). You need a receiver and something to display the data on, though. The weather and other data services broadcast through ADS-B are discussed in the AIM (section 4-5-9, new as of 2011). I had previously seen XM weather in action while riding in other pilot friends' airplanes as well as with instructional clients, but decided against it due to the nature of my flying (sporadic long-distance trips - maybe one every couple months - where its really handy). Buying a receiver, and then having the data for free, was much more palatable in my case.

One of the fundamental limitations of ADS-B is that it is a ground-based system. You must be within line of sight of a ground station to receive the data. When I was learning about all of this in the summer of 2010, coverage was somewhat sparse, but transmitters were being installed in various locations throughout the country. Fast forward 18 months and the coverage was pretty good; you can see a map here (click "ADS-B" and then "radio stations"). Because ADS-B was now largely available in the western U.S, I decided it was time to give it a try. Note that large areas of the inter-mountain west are still without these stations.

Recall that 2010 was also the year the iPad was introduced, and its place in the cockpit was quickly taking root. Going to Oshkosh and back that year was the first big trip I'd taken using chart data on my iPad. There at Oshkosh I also came across the SkyRadar booth. Staffing the booth were the engineers who had built a portable ADS-B receiver, and integrated it with an iPad app, to display weather data in the cockpit.

After chatting with the SkyRadar guys a while I asked about what was inside, and was surprised to learn they were using technology I'd worked on professionally outside of aviation for the better part of the past decade. This is more of a source of personal pride than anything; I have not received any compensation from their use of this technology and do not anticipate it benefiting me financially in a material way in the future, but I felt compelled to disclose that.

With the technology coming into alignment, at a reasonable price, I decided a buy a SkyRadar receiver late last year and have now had the opportunity to use it on a couple of cross-country trips. I evaluated both the SkyRadar's own iPad app and WingX -- currently the only two iPad applications I'm aware of that will display data the receiver picks up. In subsequent posts I'll get into my experiences using the receiver on a few trips. Many screen-shots to come.

In the mean time, AvWeb has put together a pretty decent video comparing the SkyRadar ADS-B receiver and the WingX app (what I'm using) versus an XM weather receiver and ForeFllight: