Narrative Statement

0080-EX-CN-2019 Text Documents

Geophysical Survey Systems, Inc.

2019-02-11ELS_222925

                                      Narrative Statement

The requested license will enable Geophysical Survey Systems, Inc. (GSSI) to experiment with a
novel technology to improve the safety of self-driving cars—specifically, to help the vehicle stay
in its correct lane. Present-day approaches use a combination of GPS and optical sensors that
read lane markings on the pavement. But GPS is subject to multipath and other interruptions; and
optical sensors can fail when snow, dust, or rain obscures the roadway. A car or truck travelling
at highway speed may suddenly find itself in the same lane as oncoming traffic.

GSSI is developing a system that builds on the company’s 49 years of experience with ground
penetrating radar (GPR) technology. A radar array permanently attached under the vehicle looks
2 to 3 meters below the pavement, mapping the subsurface features. (For experimental operation,
the antennas may be mounted under a metal plate and towed behind the car.) The unique and
stable underground configuration of rocks, soil layers, tree roots, pipes, etc. provides for lane
accuracies of about 4 cm.

As a vehicle first drives a particular route, the system creates a basemap of subsurface features,
determining locations with precise GPS and/or visible elements such as lane markings and
permanent roadside features. The same or another vehicle subsequently stays in its lane by
matching its real-time readings to the database map.

Rather than the conventional short-pulse modulation contemplated in the Commission’s GPR
rules, the system uses stepped continuous-wave frequencies for improved dynamic range and
better performance. It complies with the Section 15.509 GPR emissions limits when measured
with the step function running.

The device has a row of twelve transmit-receive antennas mounted sideways under the car, from
left to right. The antennas operate sequentially in pairs: first 1&2, then 2&3, 3&4, and so on,
through 11&12, for eleven pairs. Each pair in turn steps through 51 frequencies, from 103 MHz
to 403 MHz, at 6 MHz intervals. Each pair dwells on one frequency for 12.3 s before moving to
the next frequency. At the end of each frequency series is a 32.7 s time pad. The sequence
repeats for each of the eleven antenna combinations, plus a twelfth period of equal duration for
calibration, during which the system does not emit RF. A full scan takes 7.92 ms (126 complete
scans per second). The fraction of time on any one frequency is 1.7 %. The design emits low-
level RF energy less than 30 cm from the ground, with all energy directed into the ground. Both
the antenna construction and the mounting location (under the vehicle or under a towed metal
plate) provide shielding that minimizes radiation other than that directed at the ground.

The device will operate only when mounted under (or towed behind) a vehicle and pointed at the
ground. It will cease operation when the vehicle comes to a halt (as at a red light). In no event
will the device operate when the vehicle ignition is turned off.

Of the three sites requested, Nashua NH is GSSI’s headquarters, while the other two sites are
chosen for their test facilities well as their challenging soil conditions.


Autonomous vehicles promise enormous advantages to society: sharp reductions in accident-
caused injuries and deaths; independence for elderly and blind people and those with other
physical disabilities; less traffic congestion; more efficient use of roadways; less time taken up in
commuting and travel; 24-hour cargo truck operation; and reduced pollution and fuel
consumption. A grant of the requested license will help to bring about these benefits.



Document Created: 2019-02-11 16:23:39
Document Modified: 2019-02-11 16:23:39

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