Photo By Capt. Ray Ragan | A test item is subjected to a global positioning system, or GPS test at the U.S. Army...... read more read more
FORT HUACHUCA, Ariz. -- Global Positioning System, or GPS is a technology that makes much of today’s technology “smart,” from a smart phone, to the smart grid, these technologies use GPS. Testing commercial and military hardware that uses GPS is part of the mission of the U.S. Army Electronic Proving Ground (USAEPG), which recently completed a test of hardware that asked, ‘what if there is no GPS signal?’
The Army uses this smart technology to enable a commander to have a virtual picture of where troops are on the battlefield and to direct munitions with stunning precision on enemy targets, all made possible, at least in small part due to GPS. However, what happens when the hardware loses GPS signal, the hardware must still work, at least partially. Interruption of a system’s GPS signal can occur naturally and by interference.
“This interference can be intentional and unintentional and in a worst-case situation the GPS receiver could be prevented from operating properly. How the GPS system reacts to this environment is critical to determining the overall performance of the system,” said Army Electronics Engineer, Eric Fisher, chief at the USAEPG GPS Laboratory.
“Part of ensuring that the GPS systems operate as intended, under severe conditions, is testing them in the presence of electronic interference which can prevent or deny live GPS signal from being used,” he added.
Fisher explained that USAEPG’s GPS Laboratory can perform many tests indoors, at the lab, using sophisticated GPS constellation simulators that can create GPS signals in a test chamber. These GPS signals can model anywhere in the world, but systems that use GPS still need to be tested in the open-air to ensure what is observed in the lab is true outside as well.
“We still need to go outside and verify the results in a real, operational environment using ‘live sky,’” said Fisher.
Fort Huachuca, where USAEPG is headquartered is uniquely suited for open-air testing and is one of the few military test ranges set-aside for this type of GPS testing. Fort Huachuca was selected over sixty years ago by the Army for developing communications equipment because of the unique geography and topography, which together makes an ideal environment to test communication technology, including GPS. The high-desert, ringed by mountains, creates a bowl shape which keeps radio frequencies (RF) from near-by Tucson, Arizona from interfering with tests.
Today, the RF spectrum is increasingly becoming a congested space, as more and more data and communication networks use RF spectrum, a shared resource for government and civilian use. Responsibly testing interference on hardware’s GPS signal in an open-air environment required a great deal coordination and care, according to USAEPG’s Radio Frequency Spectrum Manager, Duane A. Calloway.
“In any type of wireless system testing, there is the potential for risk to other systems using the same RF spectrum or frequencies. The goal is to minimize risk to an acceptable level. This is achieved though detailed test planning and obtaining frequency clearance to conduct GPS testing from the appropriate authorities,” he said.
According to Calloway, he must coordinate with local partners on and off-post, and he must also coordinate with other Department of Defense agencies, the Federal Aviation Administration and the Federal Communications Commission. This coordination ensures that the spectrum resource is used responsibly and minimizes the risk to all users or the RF spectrum.
Because GPS uses a weak signal, Fisher and the other engineers at the GPS Laboratory are able to test far enough away that is does not affect other GPS users, using the spectrum allocated by Calloway.
“We have developed test techniques that minimize the area of impact so no unintentional interference is encountered in the surrounding areas and we can still collect the data we need,” said Fisher.
Fisher’s GPS Lab has been the test site for nearly all the Army’s GPS technology. It is also the sole-certifying lab in the Western Hemisphere for the international consortium of search and rescue satellite communications, called COSPAS-SARSAT. Ensuring that technology that uses GPS works for both military and civilian use.
| Date Taken: | 09.26.2014 |
| Date Posted: | 09.26.2014 13:50 |
| Story ID: | 143395 |
| Location: | FORT HUACHUCA, ARIZONA, US |
| Web Views: | 146 |
| Downloads: | 0 |
This work, GPS testing is at home on the Army Electronic Proving Ground, by CPT Ray Ragan, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
No keywords found.
