Publications
MLS Multipath Studies, Phase 3 Final Report, Volume III: Application of Models to MLS Assessment Issues, Part 1
Summary
Summary
This report presents work done during phase 3 of the US national Microwave Landing System (MLS) program toward developing a computer simulation model of the MLS multipath effects, the experimental validation ot the model, and the application of the model to investigate multipath performance of ICAO proposals for the new...
Coordinated radar and aircraft observations of turbulence
Summary
Summary
Interim results of a program to measure and correlate radar- and aircraft-sensed turbulence in rainstorms are presented. The dissipation factor of a turbulence air mass can be measured by an aircraft and a weather radar. Comparisons are made between precipitation reflectivity and spectral width measurements as indicators of turbulence. The...
Recursive two-dimensional signal reconstruction from linear system input and output magnitudes
Summary
Summary
A recursive algorithm is presented for reconstructing a two-dimensional complex signal from its magnitude and the magnitude of the output of a known linear shift-invariant system whose input is the desired signal. The recursion has a simple geometric interpretation, and is easily extended to causal, shift-varying systems.
On best approximation by truncated series
Summary
Summary
Let T, be the Chebyshev polynomial of the first kind of degree k.
An improved technique for altitude tracking of aircraft
Summary
Summary
When simple linear recursive tracking techniques are applied to quantized altitude reports, certain errors in estimation of altitude and altitude rate can be attributed to the response of the tracker to transitions between quantization levels. These errors can be reduced by use of an estimation technique which explicitly recognizes the...
Radar Beacon Transponder (RBX) installation and siting criteria
Summary
Summary
The Radar BEacon Transponder (RBX) is a ground-based facility used in conjunction with other elements of the Active Beacon Collision Avoidance System (BCAS) to control the threat detection sensitivity level of BCAS aircraft and to convey displayed Resolution Advisories from the BCAS aircraft to the local ATC terminal facility. This...
The effects of microphones and facemasks on LPC vocoder performance
Summary
Summary
The effects of oxygen facemasks and noise cancelling microphones on LPC vocoder performance were analyzed and evaluated. Likely sources of potential vocoder performance degradation included the non-ideal frequency response characteristics of the microphone and the possible presence of additional resonances in the speech waveform due to the addition of the...
Radar Beacon Transponder (RBX) functional description
Summary
Summary
The Radar Beacon Transponder (RBX) is a ground-based transponder used to control the threat-detection sensitivity level of BCAS aircraft operating in high density terminal airspace. THe RBX is also used to deliver displayed resolution advisories from BCAS to the ATC facility. The normal DABS interrogation waveforms and message formats are...
Electronic flight rules: an alternative separation assurance concept
Summary
Summary
This report presents results of a study of alternative concepts for tactically separating aircraft in low altitude en route airspace. It describes a concept designated Electronic Flight Rules (EFR) which allows aircraft to fly under instrument meteorological conditions in a manner that retains most of the freedom and flexibility of...
Active Beacon Collision Avoidance System (BCAS) functional overview
Summary
Summary
The Active Beacon Collision Avoidance System (BCAS) is a beacon-based airborne collision avoidance system that provides for cooperative threat resolution between BCAS and conflicting aircraft and coordination with the ground ATC control function through the DABS data link. All beacon-equipped aircraft in the vicinity of the BCAS are detected. ATCRBS-equipped...