The Fredwal Solution


INTRODUCTION

    Fredwal has delivered many radar transponder targets for the calibrating and aligning of the radar parameters.  We recommend that specific tailoring of the transponders be employed to improve their performance with your radar system.  The Accu-Phase Array Antenna Patterning System can be optimized for your requirements with minor variations in the generic system configurations.

        Modern radar systems utilize sophisticated phased array radar antennas to provide unique capabilities that will very accurately track multiple targets and can instantly scan the whole field of view of the antenna.

These antenna systems are completely tested at the radar manufacturer prior to delivery and installation at a military agency.

Unfortunately these complex systems cannot be field tested to verify their continued accuracy, integrity and performance.

There is presently no means to verify the thousands of radiating elements or their associated circuitry.

Combining Fredwal's unique phase coherent target, Model No. 2001-0100, with the remarkable accuracy of the current Global Positioning System Fredwal has developed a very accurate "cost effective" antenna testing system that will measure the performance of an operational phased array radar system in the field.

The Fredwal system will verify the tracking accuracy (measure the azimuth / elevation tracking error) across the complete field of view of the antenna.

The system will also determine the relative antenna gain, (acquisition and tracking) across the field of view of the antenna.

This important advantage must be emphasized. There is no operational “down time” of the fielded radar. The antenna is not removed from the pedestal.

There may be some offline effort to provide the radar output in an RS-232 format to record the parameters.

Fredwal's portable low cost target and several hours of helicopter time provides a most cost effective means to evaluate the accuracy and integrity of any phased array system.

The helicopter flies a multi-bar pattern at a constant altitude per pass across the field of view of the stationary phased array antenna.

This usually is about +/- 30 degrees azimuth along a normal to the antenna. A series of passes would be flown, from about 5 degrees to 30 degrees in elevation.

These increments should be somewhat less than a 3 dB beamwidth of the tracking radar.

This is the only phased array antenna testing system that can measure azimuth and elevation tracking errors.

 

Radar azimuth and elevation tracking angles are compared with surveyed angles determined with a differential global positioning system.

These tracking errors will be examined over
the full field of view of the phased array antenna.

The Fredwal system will also identify any “holes” in the search or tracking radiation patterns caused by deteriorating or damaged elements.  and will verify the accuracy of the radar range.

The most unique aspect of this concept is that a complete antenna performance test can be made while the radar system is operational “in the field”.