Reflecting the dramatic changes and advances that have taken place in the applications of positioning technology over the last decade, the plenary session of the 37th meeting of the Institute of Navigation’s Satellite Division did not discuss satellites at all. Instead, two keynote speakers elaborated upon the application of positioning to emergency response services and to airborne mapping with lidar technology.
Emergency Location Service (ELS) in Android
Steve Malkos, technical program manager at Google, told the audience of approximately 800 that the new emergency location service “is our passion project at Google. Just last week we announced the expansion of ELS into the U.S. It’s here and it’s ready today. But the work isn’t done yet because of various challenges.” Google’s goal is 1-meter location accuracy for all 911 calls placed on cell phones. The algorithms discussed at ION this week, Malkos said, are part of what is driving Fused Location Provider (FLP)
toward this future.
In FLP, locations are computed directly on the handset as opposed to the older method, which computes on the carrier’s cell network. Google’s indoor solution consists of wi-fi augmented by network information.
Recently released statistics show emergency call usage has flipped from what it was only a decade ago. Now, only 20 percent of emergency calls are placed on landlines. Eighty percent are placed on wireless devices.
Malkos replayed audio from a call made recently, prior to activation of ELS, that generated a location on Miami’s emergency services of 500 meters away from the basement ballroom of the conference hotel.
Domino’s Pizza, Uber ride service and Facebook all now use the hybrid derived location from cell phones, while emergency services typically use the location computed on the carriers’ network, and relying on cell-tower positioning. Cells range from 100s of meters to kilometers in size.
ELS has been live in the U.K. since June 2017. Since its activation, British Telecom’s mean radius accuracy on emergency calls went from 2 kilometers to 43 meters 85 percent of timeION20.
Malkos discussed the challenges of privacy, altitude (Z-axis) and the related difficulties in the urban high-rise landscape of floor determination and infering floor labels.
Overall, he said, statistics show that each 1 minute sooner of arrival of emergency services translates to 10,000 saved lives.
A Lidar History
Paul LaRocque, vice president of special projects at Teledyne Optech gave an overview of light detection and ranging (lidar) development through the lens of a one-company centric history, that of Teledyne.
Lidar got started in 1969, within a decade of the invention of the first laser. It began with early work in marine mapping and bathymetry from onboard ships. Airborne lidars developed in the late 1970s, looking at icefields in the Arctic, and was done at first with no absolute positioning to aid in analyzing the results..
Early on, developers discovered that airborne lidar can get to the bare earth, penetrating under forest canopy. This eventually led to the recent dramatic discoveries of long lost Mayan cities, covered by jungle.
In the early 1990s, GPS and inertial technologies converged, with some miniaturization, to enable building of integrated technology systems that added absolute positioning to the lidar toolbox.
LaRocque provided a quick look at the National Geographic story, based on data from a three-wavelength Teledyne Optech Titan, one of several current machines that are generating data at millions of shots per second. Increasingly, it’s the software processing that brings out the accuracy, for example, centimeter accuracy surveyed from a kilometer up in the air.
Challenges enumberated:
- the speed of light is not fast enough.
- the Earth is not flat enough.
Teledyne developed PulseTRAK technology to cope with the “blind zones” generated by these two challenges, so as to not lose data in any gaps.
The new frontier is spaceborne lidars. Teledyne is involved in a project tenerating lidar data from the surface of Mars on a Canadian space agency mission. This led previously to the discovery of snow in the atmosphere of Mars. The OSIRIES-Rex mission now on its years-long voyage to a very-far off asteroid represents the furthest adventure of lidar in space. The project will collect data on the asteroid’s surface and beam it back to Earth, as well as eventually returning some core samples.
We covered the tools to help analyze GNSS measurements. How strong are the individual measurements? How accurate are the range measurements? With these tools, developers now have direct insight into the lowest layers of a GNSS receiver. Then came activity recognition algorithms (15:40) and how deep neural networks will improve the precision of these algorithms and help advance the field in activity recognition.
