Research on The Measurement Method of The Space Field Strength of The Localizer Coverage Signal and The Comparison of The Relevant International Standards
Li Wang and Mao Ge, Flight Inspection Center of CAAC
Location: Regency Ballroom
There are two methods used to evaluate the coverage of the localizer (LOC) signal in the Flight Inspection field at present. One is measuring free space field strength in terms of microvolt per meter (?V/m) or decibel-watt per meter squared (dBW/m2), the other is measuring signal strength output of FIS Navigation Receiver in terms of decibel-milliwatt (dBm) or microvolt (?V). As far as we know, many flight inspection organizations in the world evaluate the coverage of the LOC in terms of the received power level dBm. Understanding how the antenna converts the free space field-strength into received power and the conversion factors involved is critical in assessing the actual LOC coverage value.
This paper presents the conversion formulas between the free space field strength requirements and the received signal strength through the LOC antenna characteristics and how the LOC coverage values are derived from the receiver signal strength measurements. This paper also researches the difference between ICAO and FAA standards, and finally puts forward a solution to decrease the difference.