GPS has a number of inherent weaknesses in terms of availability and integrity of information to provide a position solution that can be relied upon. The use of inertial sensors to provide an augmentation to GPS is a common approach in overcoming these weaknesses and to improve performance for demanding applications.

INERTIAL NAVIGATION SYSTEMS

An Inertial Navigation System (INS) provides position, velocity, orientation and angular velocity by measuring the linear and angular accelerations applied to the system.

Integrated GPS/INS (IGI) systems are essential for high dynamic platforms and provide continuous navigation during RF interference or weak/degraded satellite signal conditions. While GPS/INS system testing may be conducted on the host platform (such as an aircraft), this approach is prohibitively expensive for extended tests and does not allow for repeatability under controlled conditions. A more cost-effective approach is to test the GPS/INS system in the lab. This can be achieved by generating coherent GPS satellite signals and inertial delta-V/delta-theta terms for a specific trajectory and providing these inputs to the system under test.

Spirent offers a number of GPS inertial navigation test systems designed to simulate the inertial sensor outputs coherently with simulated GPS RF, thus enabling the inertial receiver elements to be tested. In addition, Spirent has a turntable option available for stimulation of embedded inertial sensors coherent with simultaneous GPS simulation.

Spirent Products

Spirent supports a variety of GPS/INS interfaces, including:

EGI’S

• Honeywell H-764G EGI, SIGI and NAV100™
• Northrop Grumman LN100, LN250, LN251 and LN260

IMU EMULATION

• Honeywell HG-1700 and HG-1900 (as used in JDAM, for example)
• Northrop Grumman LN200
• AMRAAM compliant IMUs
• NATO STANAG 4572
• Atlantic Inertial Systems IMUs

*Authorisation may be required

SPIRENT'S VALUE FOR INERTIAL NAVIGATION TESTING

Our systems support high dynamics, classified signals (including GPS M-code), GPS/inertial, interference and jamming simulation. Our software enables you to set up challenging test cases to assess performance and integrity in a wide range of normal, extreme and error conditions, benefits include:

• Test blended navigation solution in the laboratory
• Test under a range of regular and extreme dynamics
• Error state testing
• Enables characterisation and optimisation of GPS/inertial systems