Trex Aviation Systems FODXFV2 Foreign Object Debris Radar User Manual
- June 6, 2024
- Trex Aviation Systems
Table of Contents
Trex Aviation Systems FODXFV2 Foreign Object Debris Radar
Fixed Platform (Tower) Installation
Radar mount assembly with azimuth/elevation pointing adjustment, attached to a tower using U-bolt hardware
Radar mounted directly to fixed az/el positioner
Mobile Platform Installation
Radar is integrated with light bar, mounts to vehicular roof rack
Radar DC Power and Data Connections
- DC power is provided through a 5-pin Amphenol connector P/N PT06A-14-3P(SR)
- Radar powered by +24VDC at approximately 3A
- Data transmitted through standard Cat-5 cable, interfaced with Amphenol connector and shield P/N RJFTV6MG
- A clip-on one-turn inductor, Fair-Rite P/N 0443167251, is integrated with each cable to reduce the radiated emissions below FCC limit specifications
Radar Beam Orientation
The radar beam is concentrated by a microstrip patch-array antenna, onto a
sector of 120 degrees in azimuth by 1 degree in elevation. This fan beam scans
with RF frequency over 4 degrees of elevation during every chirp. The radar is
mounted to align the area of surveillance with this window.
FCC info and Caution to the user
This device complies with part 15 of the FCC Rules. Operation is subject to
the following two conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation. Note that changes
or modifications to the Radar unit not expressly approved by Trex Aviation
Systems could void the user’s authority to operate the equipment.
System Power-Up
The FOD Finder XFV2 radar system power is delivered from a power box at the
base of the tower, or on a service platform within 10m of the radar unit. The
power box includes a circuit breaker switch that controls AC power. AC power
activates an AC-to-DC power supply that provides 24VDC to the unit. When the
AC circuit breaker is turned on, the radar unit starts a 3-minute boot-up,
initialization and calibration sequence. After this time interval the unit
begins transmitting RF power and processing the radar returns.
Startup Instructions: Run-Time Software
Open the Program Folder “Static-CDMA” as shown to the right
Double-click on the “Processing” tab as shown to the right
Open the “CDMA_Multi Radar” script:
The radar begins transmitting, and return data are displayed in a blue box of varying colors, indicating the magnitude of the signal. Slider bars above the return image can be adjusted via the computer mouse, to alter the display or select system operating parameters.
FOD Finder Radar Calibration and Verification
The FOD Finder XF radar requires an initial calibration to operate at optimum performance. The calibration procedure measures the relative response, in- phase and amplitude, of all transmit and receive channel combinations in use by the radar. This calibration data is collected by acquiring radar data from a single, strong return source placed in the radar far-field, such as a corner cube, and is measured at twelve different frequencies across the radar band. The calibration data is then stored on the internal radar processor and applied to all radar signals during operation to produce a high-gain beam shape. Importantly, this calibration is applied at the data processing level and does not require any adjustment of the radar system hardware. Data for a new calibration can be generated by observing radar returns from a known target and a new calibration can be applied simply by re-writing the calibration file on the radar.
The FOD Finder radar is fully calibrated at the factory and then an additional calibration is performed on-site at the time of installation. Calibration is verified by measuring the return signal from a radar target with a known radar cross-section. The system continues to automatically update its phase calibration during its operation based on the data returns from fixed objects within the radar field-of-view, comparing the returns from those objects at the time of installation to the returns from those objects at the present time. No input is required by the operator for the calibration update to occur.
The radar calibration is a function of the relative electrical line lengths of traces within the radar and the impedance of the radar MMW circuits. If no physical changes are made to the radar, these values do not change appreciably. There may be small changes in the system parameters over time due to changes in temperature or aging of components. Automatic updates to the calibration files, based on the returns of known objects in the field of view (such as runway landing lights), are incorporated to correct for these small changes over time.
Calibration of the radar is verified by monitoring returns from fixed objects within the radar field-of-view and comparing the current phase and amplitude of returns to those measured when the radar was first installed. This requires no user action, assuming said data is exportable to Trex Aviation for analysis. As part of a standard system performance verification, current radar returns and calibration data are exported to Trex Aviation and the validity of the updated calibration file is confirmed. A visual image of a runway with side marking lights and a runway centerline light is shown on the next page. While this is a visually reconstructed image, the data used are those needed to verify the system calibration. Phase and amplitude returns from selected point targets, such as the landing lights (which appear as white dots in the image), are used for calibration verification.
FOD Finder Radar Calibration and Verification (cont.)
This reconstructed radar image of a runway relies on data processing using the calibration file; data from bright point targets are used to verify that the calibration is current. As part of system self-monitoring and self- calibration, the radar verifies the accuracy of its own calibration by logging data from fixed point objects within the radar field of view and comparing return levels to those measured at system installation. If it detects that these returns have fallen below a threshold level, even after an attempted self-calibration effort, the radar will alert the operator with an error message and request that the data be exported to Trex Aviation for external re-calibration.
RF Safety
The FOD Finder™ XFV2 radar transmits RF power at 78-81 GHz out of a radome
making up the front face of the radar enclosure. The MMW energy travels thru
the white face plastic, where it diverges at an angle of approximately 120
degrees in azimuth and 1 degree in elevation. Over a sweep period of
approximately 50ms, this fan beam is swept over a range of 4 degrees in
elevation.
The FCC Maximum Permissible Exposures (MPE) for this operating frequency are a
power density of 5mW/cm2 averaged for a time duration of 6 minutes max for an
operator and 1mW/cm2 averaged for a time of 30 minutes max for the general
public. When working with this product powered up, the operator should not
stand in front of the unit, any closer than 20 cm from the radome where the
radar beam is emitted. When the unit is installed where the General Public may
be exposed to the radar beam we suggest the general Public should be kept away
at a distance greater then 3 meters from the front of the radar where the beam
is emitted. At this distance, the exposure level is .005 mW/cm2 or 0.5% of the
MPE threshold.
System Warranty and Troubleshooting
The FOD Finder XFV2 radar system is delivered with a one-year warranty from the date of installation. If issues arise during system operation the first step is to power down the system and restart after 30 seconds. If performance issues persist, a screenshot of the user display should be taken and sent to the system installer.