OSH 2014 - no good ADS-B out solution

Last week I went to Oshkosh. It was a trip I have done before, and I really enjoy spending time there. Usually it is very reinvigorating. This year I had some personal strains, but overall it was a good time. I saw some friends, and I got to checkout some new stuff.

Garmin was there with their connected cockpit stuff. I couldn't get a good feel for the low level technology, the booth folks were pretty high level. It may be more open than I got the feeling it was. Overall it seems as long as you buy Garmin stuff you are golden.

I mostly was hoping I could find that elusive vendor, the one who gets electronics, and wants to sell a million units. Right now I think the field is ripe, and people are ready for an ADS-B solution that is open and cheap. The field is still limited by the usual suspects and their belief that avionics have to cost a good portion of my annual salary. I didn't find that vendor.

I have a strong belief that someone could build a really good UAT (or even 1090-es) ADS-B unit that would cost under $1000, that would connect to an external GPS device, since it has to have WAAS quality position indication. The device would talk NMEA and/or ARINC-828/708/429 and allow any MFD to display the ADS-B and TIS/FIS messages as well. I think the under $1000 would be the tipping point, and suddenly a majority of the GA owners would finally be signing up for these devices at the local avionics shop.

Mitre developed a prototype UAT that they believed could do everything that I am describing, and showed it at AOPA expo in 2010. It was a standalone transceiver that  used an iPhone for a display. It was a full UAT capable of being certified.

Think about a smart phone. There are a bunch of teardown sites that will calculate the material cost of the devices. The costs are the CPU, the display, batteries and radios. Yes, most smart phones contain multiple radios, including WiFi, Bluetooth, LTS, HSPA, and probably GSM on multiple bands (850/900/1800/1900 MHz). There are so many radios in a smart phone, I am surprised the FAA lets 'em on a plane, but that is why the airlines want cellphones controlled a little bit. The typical smart phone costs about $150-300 in parts. There is certification, assembly, shipping and marketing to add on top of that.

I know cell phones transmit less than 1 watt, and UAT's will transmit up to about 50 watts. A well designed linear amplifier shouldn't cost more than maybe $20 in parts to get 50watts at 978MHz. It would be a few discrete components (resistors and capacitors) and probably 6 FET's.

If the bill of materials for the UAT is around $300, that doesn't justify the 5-8 times cost of the current crop of units. There may be arguments about volume and costs, that is understandable, if the price is at the high end, and the volume is not there. No marketing campaign will convince every to buy the top of the line equipment ever. If the price is in the sweet spot, the volume is there and you can amortize the fixed certification and development cost across many more units! ROI goes up, bonuses to everyone, and the stockholders are happy.

I see plenty of follow on products, including a behind the panel GPS WAAS (SBAS) receiver, that has an LAAS (GBAS) option. I see some panel mount MFDs that could be built and sold using Android in the Car type setups. Probably some VHF transceivers that might complement this stack of radios. If this system follows an open standard, such that it would mix and match with other manufacturers equipment, including IMU's and such, then the consumer wins.

Want to do it? I am willing to work with someone who think the current avionics market is a total mess, and needs significant help!

Android ADS/B in for $20 available NOW!

It is finally available! I predicted it about a year ago, when I first ordered my tablet, and thought about writing it myself, and asked for help. I am glad there are more ambitious people out there, because they get it done. My Android development skills aren't there yet either. I am working on an app that will use maps, but haven't got to that part yet.

The app is $1.50 in the PlayStore, called ADS-B on USB SDR RTL (beta)  it shows up in apps called "USB ADSB..." on the tablet. The USB dongles are really only about $15-20 US, plus shipping. You will probably need an OTG cable or adapter for a phone or tablet. (The OTG cable allows attaching USB client devices like mice and keyboards to a phone or tablet). Really the cost may approach $50 plus a tablet.

The app shows promise, and really looks nice. It starts the map centered on Lakeland Florida, so it needs to be adjusted to where you are. The maps can be sectional, WAC, IFR, and street maps, and can be selected from a menu. The pinch to zoom works, but the menu allows zooming, along with buttons in the upper corners.

When the app comes up, it displays all the available devices, selecting the available device starts the app. The top part shows the map, the bottom part shows a list of the aircraft that the software has heard recently (can be adjusted in startup menu, defaults to 60 seconds).

It appears to be listening for 1090MHz Mode S with Extended Squitter (ES) transponders. 1090ES is the world wide standard. GA in the US will probably focus mostly on the 978MHz UAT devices, since there is more bandwidth available to those devices. See UAT or 1090ES in my other blog).

The developer says it will have weather eventually. Weather alone would make this app worth while, but the aircraft positions is a huge benefit. "Mounting" a tablet in an aircraft isn't hard, and there are a few adapters to make it easy. 

This doesn't completely compete with the Garmin GDL-39, and their Pilot app, but it will give you the chance to see what is possible, and the benefits to having ADS/B service.

I had trouble using it. The SDR dongle is very sensitive to the antenna chosen. I found a link to a site were there are extensive design and testing of antennas especially for ADS-B reception:

http://forum.planefinder.net/threads/ads-b-diy-antenna.23

I chose the simple 1/4 wave dipole and was able to get some reception. I didn't want a large antenna, nor an amplified one. I want to be able to use this portable in rental aircraft and such. It did seem if I got the SDR farther away from the tablet, it worked better. I used a USB extender to do that.

The battery life doesn't seem to be negatively affected running the SDR dongle, the screen still eats most of the battery. Someone suggested a split OTG cable, so it could be connected to power while running the SDR dongle. That is a great idea.

I can't say this will save a life, or replace TCAS for alerting, but it could help someone get the big picture when ATC calls out traffic.

If everyone only does ADS-B in, it looses some of the benefit. The future will require us to use ADS-B out as well, then everyone should be on the same level.