As the end of the year approaches, I’d like to reflect on 2013. One of the new features of the GPS World website allows me to access webpage statistics so I can understand which articles and news items were “hot.” Following is a list of GPS World magazine’s hot topics for 2013 with some commentary from me.
Top 5 Most Popular Pages at GPSWorld.com in 2013
While it seems everyone is conducting webinars today, GPS World was a pioneer in offering technical webinars more than six years ago, and they continue to be very popular today. Three of the latest webinars are:
- Detect and Locate GPS Jamming
- Unmanned Aircraft Navigation
- What’s the Latest & Greatest? GNSS Products for 2014 and Beyond
As a side note, I’m trying to talk the GPS World publishers into allowing me to host a bi-monthly or monthly 60-minute radio show hosted by myself and featuring various GNSS industry guests. The show would be an informal, roundtable discussion about current events related to high-precision GNSS and similar technology. It would likely be broadcast live over the Internet as well as recorded in MP3 format so you could listen to it using your smartphone or music device at a time convenient to you. Please send me a quick email if you think this is something you’d be interested in listening to.
I wrote this article in March 2013 discussing the myriad of new RTK receivers recently introduced. Since the article was written, even more have been introduced! Smaller, lighter and cheaper is where RTK is headed. The fact that this article was GPS World’s second most visited web page in 2013 speaks volumes of the growing interest in centimeter-level, real-time positioning (RTK).
Just recently, my friends at the University of Texas at Austin (UT) took RTK where it hasn’t been before…on a smartphone.
Dr. Todd Humphreys and his graduate assistants, including Ph.D. student Ken Pesyna, are part of the UT Radionavigation Laboratory. This team has been exploring, among other things, the feasibility of implementing RTK technology on smartphones. If you recall, in 2012 at the GPS World dinner during the Institute of Navigation (ION) GNSS Conference in Nashville, Dr. Humphreys proclaimed that RTK technology will be readily available on smartphones and tablets by the year 2020.
Well, Dr. Humphreys and his team are doing their part to realize this vision. Just a few short weeks ago, he reported that they have enjoyed some initial success.
However, before I present the details, I’ve been reminded several times over the years that smartphone GNSS chipsets aren’t the problem. In fact, two of the key GNSS engineers on the team (Broadcom) that designed the GNSS chipset used in the Apple iPhone, Dr. Frank Van Diggelen and Charlie Abraham, used to work for Ashtech. They know RTK.
The challenge with implementing RTK in smartphones is the antenna, not the GNSS chipset.
“The smartphone GNSS antenna is nothing more than a cleverly-designed wire trace, as are all smartphone GNSS antennas,” said Dr. Humphreys. “Some have joked that you could do better with a paperclip, and that’s probably not far from the truth.”
Nevertheless, just a few weeks ago Dr. Humphreys and his team at UT were able to use a standard smartphone antenna (Samsung Galaxy SIII) to achieve an RTK solution. To his knowledge, this is the first time a successful RTK solution has been derived using an off-the-shelf smartphone antenna.
Ken Pesyna added that RTK initialization took a little under seven minutes using seven satellites. He added that with 10 satellites in view he’s seen RTK initialization drop to about two minutes. Mind you, this is GPS L1-only. Certainly, the addition of L2, GLONASS would further reduce initialization times, not to mention BDS, Galileo, etc.
So, RTK in smartphones next year? Not so fast.
“Many challenges remain”, said Dr. Humphreys, “and in some senses we are cheating (big backplane, good clock). Nonetheless, this is a huge step forward that presages great disruption.”
He added, “We were astonished to find that we could track L2C signals through the smartphone antenna. We didn’t exploit the L2C signals in our solution, but we could have, as the L2C carrier we recovered was quite clean.”
Not far behind the RTK article, in web hits, was the article I co-wrote with Mark Silver on various free online post-processing services available to the general public. The article was super timely, as it was published a day after the U.S. government shutdown and the NGS OPUS website went blank. Therefore, thousands of GNSS users read the article in a very short amount of time.
Dr. Minghai Jia, a key developer of Australia’s AUSPOS online GNSS post-processing service, commented, “This is an excellent article, which has boosted AUSPOS demand significantly.”
Number four on GPS World’s website for 2013 was Tony Murfin’s article on the real-time PPP landscape.
Whereas the real-time PPP landscape remained relatively unchanged for many years, with OmniStar and Starfire services being the only games in town for satellite-based precise positioning on land (as opposed to off-shore), this landscape is changing.
In 2012, TerraStar began offering a commercial service very similar to OmniStar and Starfire — real-time decimeter positioning using corrections delivered via satellite (no terrestrial Internet connection required).
Also in 2012, Trimble introduced its satellite-based RTX service, touting 4-cm real-time PPP accuracy.
In April 2013, the IGS announced it began offering a public (free) real-time PPP decimeter service (IGS RTS). While only supporting GPS initially, IGS plans to support GLONASS by the end of 2013.
The challenge for both TerraStar and IGS RTS is that receiver manufacturers need to integrate firmware to utilize these services. It’s unlikely that those companies offering competitive services that also design GNSS receivers (Trimble, Navcom) will do so, thus making it difficult for the new services to gain market traction.
Rounding out the Top 5 GPS World web pages of 2013 is The Almanac, featuring GNSS constellation tables compiled by Prof. Richard B. Langley at the University of New Brunswick.
If you want a single, comprehensive webpage that lists all the navigation satellites from the various constellations, this is one you should bookmark in your web browser. Heck, there’s even a PDF version of it. GPS, GLONASS, Galileo, BeiDou, IRNSS, and public SBAS systems are listed in detail as well as many useful links to various GNSS resources.
An updated Almanac will appear in the January issue of GPS World.
Happy Holidays, and I’ll see you next year.
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If you are not quite feeling the holiday spirit, take a look at these wonderfully talented people in this four-minute music video. They don’t use any instruments besides their amazing voices.