Drone Moans and Satellite Woes

November 14, 2013  - By


As some of you may know, I also write a monthly column for Geospatial Solutions, which is all about geospatial technology encompassing GIS, surveying, engineering, and anything regarding geospatial technology. On occasion, I write something that fits very well with both my Survey Scene newletter and Geospatial Solutions Monthly newsletter. This is one of those months.

Drones, UAVs, UAS…whatever you want to call them, are getting a lot of press coverage, both in the mainstream media and the surveying trade media. Rightly so — there are a terrific number of uses for drones in surveying and mapping from forensic mapping to crop monitoring to creating terrain models for volume estimations. A little later below, I’ll give you a link to my more detailed article about applications and my personal experience.

In this article, I’d like to focus on the U.S. law regarding using drones for commercial purposes (eg. mapping, surveying, etc). I’ll start with a blanket statement.

Under the current law, it is illegal for any commercial entity to operate a drone in the U.S. Period. 

The only exception is that the Federal Aviation Administration (FAA) is issuing special airworthiness certificates in the experimental category for testing, market survey, and training of drones. However, the FAA specifically states that drone users awarded such an experimental certificate are not licensed to use drones for “hire or compensation.”

The only other possibility is if the commercial entity has an airworthiness certificate for the drone like what’s required for any other aircraft such as an airliner. However, you can bet that no drone within your price range has such a certificate.

What about hobby users?

This is where it gets interesting and where some commercial users think there is wiggle room.

Under the current FAA rules, hobbyists (the FAA calls them modelers) can fly drones up to 400 feet above ground level (AGL) and must notify the airport operator if flying within three miles of the airport. Hobbyists are covered under the AC 91-57 rules, a simple one-page document.

Some (maybe many) companies and/or individuals who are operating drones for mapping in the U.S. think this is a loophole in the FAA rules, and that as long as they do not charge for the drone flight-time, they are not violating the FAA rules (they say they only charge for processing the data). The FAA begs to differ. When I asked the FAA this question, FAA Spokesperson Alison Duquette responded:

“They would be violating FAA rules. Please read this policy link. The FAA recognizes that people and companies other than modelers might be flying UAS with the mistaken understanding that they are legally operating under the authority of AC 91-57. AC 91-57 only applies to modelers, and thus specifically excludes its use by persons or companies for business purposes.”

This begs the question, is the FAA following a “don’t ask, don’t tell” informal policy? The best way to determine this is to look at their enforcement activity. When I asked the FAA if it would send me the list of enforcement activity regarding drones, the agency said I’d have to submit a Freedom of Information Act (FOIA) request, which I did this week. I’m told by my colleagues it may take some time before I get a response.

I know of at least one instance where the FAA told an entity to shut down its use of drones. Take a look at this three-minute CBS news video.

My Geospatial Solutions article “Is it Legal to Fly Drones for Mapping in the United States?” explores this topic in more depth.

Let’s talk a little about RTK

Last month’s article about post-processing alternatives, “Seven Free Alternatives to OPUS GPS Post-Processing During U.S. Federal Government Shutdown,” was one of the all-time, most-read articles ever published on the GPS World website. It’s ironic because I’m not a fan of post-processing in general. Mind you, I coordinated the development of several post-processing (both L1 and L1/L2) software packages back in the 1990s, so it’s not like I’m afraid to post-process or don’t understand the technology. It’s just that it’s so inefficient compared to RTK. However, I do concede that OPUS, AUSPOS, CSRS, Centerpoint RTX, GAPS, Scout, and MagicGNSS online post-processing tools combined with an increasing number of publicly available, worldwide GNSS reference stations make centimeter-level post-processing a lot easier (and less expensive) than ever before. It seems like a lot of you still prefer it!

RTK technology is advancing too, from both a receiver perspective and a satellite system perspective. Which geographic region of the world do you think is the most well-suited for RTK positioning?

It may seem like an odd question, and it would have been to me had I not attended the ION GNSS+ conference in Nashville, Tennessee, in September and the Intergeo 2013 conference in Essen, Germany, in October. How could one geographic region be significantly better for RTK positioning than another? Terrain? Nope. It’s the same country that consumes more L1/L2 receivers than any other country in the world: China.

Why China? A picture (well, two pictures) is worth a thousand words:


BDS (BeiDou) orbit plot.


BDS (BeiDou) coverage map.

At this point, China’s BeiDou (now referred to as BDS) navigation system is a regional system. If you look at the above graphic of the BDS satellite orbits, you can see the satellite figure eight orbits above southeast Asia. These satellites, combined with GPS and GLONASS, give the RTK user a tremendous number of usable satellites. Furthermore, since the BDS satellites are in figure-eight orbits, they stay “in view” longer ,which is ideal for RTK.

The result is that GNSS users in the BDS coverage area have more satellites in view than any other region in the world, and we all know that more satellite observations make for better RTK positioning.

China’s plans don’t stop with BDS being a regional system. By 2020, China says it plans for BDS to be a global system similar to GPS and GLONASS. The BDS presenter at ION GNSS+ said, “China always regards BeiDou belonging to both China and the world.”

GPS and Galileo Delays

Meanwhile, as it seems China is pushing forward, both GPS and Galileo suffered delays last month.

The fifth GPS IIF satellite (IIF-5) launch scheduled for last month was postponed. A fuel leak in the Delta 4 launch rocket seems to be the culprit. No new launch date has been scheduled for IIF-5. The United Launch Alliance (ULA) issued the following statement:

“The ongoing Phase II investigation has included extremely detailed characterization and reconstructions of the instrumentation signatures obtained from the October 2012 launch and these have recently resulted in some updated conclusions related to dynamic responses that occurred on the engine system during the first engine start event.

“The GPS IIF-5 Delta IV launch is being delayed to allow the technical team time to further assess these updated conclusions and assess the improvements already implemented and determine whether additional changes are required prior to the next Delta IV launch.

“The Delta IV booster for the GPS IIF-5 mission has completed the standard processing and checkout on the launch pad and will be maintained in a ready state for spacecraft mate and launch pending completion of this assessment. A new launch date will be established when the assessment of the updated dynamic response information is completed in the coming weeks.”

Meanwhile, Europeans have been waiting on pins and needles for the first production launch of dual Galileo satellites. A fall 2013 launch date was expected, but has been postponed until Summer 2014.

According to European officials, the European Space Research and Technology Centre (ESTEC) thermal vacuum chamber for testing satellites under orbit conditions was not ready for the two FOC satellites delivered by OHB in late summer.

The satellites thus cannot ship to the Guiana spaceport in South America in time for a planned 2013 launch on a Soyuz rocket. The Galileo schedule is also running into bottlenecks with scheduled launches by other satellite programs aboard Guiana Soyuzes.

A six-week test of the first Galileo satellite at ESTEC reportedly got under way in October.

The pressure is rising for Galileo to start delivering usable satellite observations, which China is already doing, albeit for themselves and their neighbors.

See you next month.

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This article is tagged with and posted in Opinions, Survey, UAV/UGV

About the Author: Eric Gakstatter

Eric Gakstatter has been involved in the GPS/GNSS industry for more than 20 years. For 10 years, he held several product management positions in the GPS/GNSS industry, managing the development of several medium- and high-precision GNSS products along with associated data-collection and post-processing software. Since 2000, he's been a power user of GPS/GNSS technology as well as consulted with capital management companies; federal, state and local government agencies; and private companies on the application and/or development of GPS technology. Since 2006, he's been a contributor to GPS World magazine, serving as editor of the monthly Survey Scene newsletter until 2015, and as editor of Geospatial Solutions monthly newsletter for GPS World's sister site Geospatial Solutions, which focuses on GIS and geospatial technologies.

3 Comments on "Drone Moans and Satellite Woes"

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  1. John Koles says:

    Eric I agree with you, Post processing is so old school and cumbersome. Like comparing Radio Valves to modern Asics. However I think it should still be taught in Surveying/Spatial sciences just to understand the theory so that students do not think of GPS as a black box solution. Since RMIT lecturer Nick Talbot came up and published an efficient RTK data correction transmission format CMR, RTK has become the robust and the mainstay of GNSS surveying for most Survey applications except for Cadastre.

  2. Karl says:

    Nice article but, please, no autoplay of video.