 Radar
Performance Evaluation Tool
The Radar Comparator (RC) is an essential tool for radar
performance analysis based on operational data from one or several
radars. It forms one of the analysis modules of RASS-R, and takes
its data from the DHM module.
The RC uses single-radar opportunity data for the calculation
of probability of detection (Pd), false plot rate and correct
(SSR-) code probability. It uses dual-radar data for the calculation
of the systematic errors (Range, Gain, Relative Time, Azimuth
biases) and accuracy measurements (Range, Time and Azimuth errors).
Moreover Range, Time and Azimuth accuracy can also be estimated
using mono-radar data only.
As opposed to other existing radar measurement tools, the
RC features a unique method for trajectory reconstruction as
well as the radar data preprocessing taking into account the
real barometric pressure distribution with height, RF wave refraction,
radar ACP encoder eccentricity, and random timestamp errors.
The barometric height correction is applied using the atmospheric
soundings data automatically retrieved by the tool over the internet.
This type of correction is very important both for mono-radar
and dual-radar analysis, producing a better accuracy on the actual
position of AC and actual coverage volume of the radars.
The Radar Comparator in dual-radar mode uses no more than
two sources of radar data at a time. It is proven that with two
remote radars having a representative amount of common coverage
opportunity traffic data an absolute measurement of the systematic
errors and random errors of both radars is possible.. As a result
of such dual-radar measurement the true trajectories are produced
with on accuracy exceeding the positional accuracy of either
of the radars. The measured systematic errors can be used for
radar data corrections prior to feeding them into a multi-radar
tracker. A radar under test can alternatively be compared with
GPS or ADSB data. The RC tool uses the high resolution screening
angle files produced from the accurate digital terrain data,
generated by the CMC Module in RASS-R. All the data corrections
and processing steps are transparent to the user. All the intermediate
results are graphically presented on the displays, supplied with
cross-referencing cursors, which is essential in tracking data
flow and detecting exact reasons for the eventual malfunctioning
and errors.
The Radar Comparator is by far the most efficient Radar
Analysis Software on the market and represents an easy-to-use
tool for radar performance analysis using opportunity traffic
data.
Evolution
Several studies on multi-radar methods of analysis as
well as the operational experience with EC SASS-C MURATREC
(multi-radar
trajectory reconstruction software) have shown that
using data coming from many sources (radars) in the measurements
 does
not necessarily improve the accuracy of the result.
Neglected systematic errors such as for example ACP eccentricity,
barometric
error etc. will have negative influence on the results.
That is why the careful measurement and preprocessing of
the data
before they can be used for multi-radar comparison
is a must. Dual radar analysis as opposed to the multi-radar
analysis
provides a number of benefits. Even if all known systematic
errors (eccentricity, barometric, refraction etc.)
are properly handled, in real radar environment some other
unknown errors
might appear, as for example wrong positioning, wrong
antenna height settings, local anomalous atmospheric conditions
and
so forth. In such cases when the multi-radar data are
combined from many radars, unexpected errors may seriously
contaminate
the results, and it becomes impossible to determine
what the actual source of this new error is.
Methods
- Corrects input data for all known systematic errors: ACP-encoder
eccentricity, barometric height error (automatically
retrieving the data over the internet), range error due to
the atmospheric
refraction, and random timestamp error
- Uses mono radar opportunity traffic data for calculation
of the probability of detection, false plot rate,
codes probabilities, accuracy (range; azimuth; timestamp)
- Uses dual radar opportunity traffic data for calculation
of the systematic errors (range, azimuth, range-gain,
relative time biases), accuracy (random range and
azimuth errors), the
tolerances on the measurements and the general statistics
- Sets the plot coverage bits according to the screening
angles data calculated with the accurate high
resolution digital terrain data (CMC) and the actual atmospheric
conditions
- Export various data files for documenting and use
with external analysis tools
The Radar Comparator uses RASS-S4 files produced
by the RASS-R Data Handling Module (DHM) as
input. This data
can be taken from:
- Extended Data Recorder (EDR)
- USB Data Recorder (UDR)
- LAN recorder (UDP-IP or TCP-IP)
- SASS-C: MADREC
- RS3
- GPS data in various formats (COMOS, S4) can
be imported
- ADSB data (ASTERIX cat21)
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