The Radar Range Equation

ABSTRACTThe International Civil Aviation Organization (ICAO) Circular Cir 337 is the first step towards ICAO establishing an Aeroplane CO2Emissions Standard to form part of Annex 16, Volume III to the Chicago Convention. It describes itself as ‘a work in progress’. This paper reviews Cir 337 against the background of flight physics, the published literature on aircraft fuel burn and CO2emissions and the current practices of the aircraft and engine manufacturers and the airline operators. We have taken, as our starting point, the aim of ICAO to reduce the fuel used per revenue tonne-kilometre performed and argue that the Breguet range equation, which captures all the relevant flight physics, should be the basis of the metric system underpinning the standard. Our overall conclusion is that Cir 337 provides an excellent basis for the initial regulation of aviation's CO2emissions and, further in the future, for developing measures to increase the fuel efficiency of the operational side of civil aviation. Our main criticism of the circular in its current form is that it does not address the ICAO goal of reducingfuel used per revenue tonne-kilometre performedand makes no reference to payload. This defect could be eliminated simply by omission of the exponent 0.24 of the Reference Geometric Factor (RGF) in the formula for the metric given in Chapter 2 (paragraph 2.2) of the circular. Retaining theRGFto the power unity in the metric and multiplying it by an appropriate value of the effective floor loading would convert it to what the 37thAssembly of ICAO called for – a statement of fuel used per revenue tonne-kilometre performed. Finally, correlating the amended metric against design range, as determined from the measured specific air range and the key certificated masses, provides a sound scientific basis for an initial regulation to cap passenger aircraft emissions.

Download Full-text

Range Equation for Passive-Infrared Devices

Proceedings of the IRE ◽

10.1109/jrproc.1959.287044 ◽

1959 ◽

Vol 47 (9) ◽

pp. 1489-1490

Author(s):

Lewis Larmore

Keyword(s):

Range Equation ◽

Passive Infrared

Download Full-text

Modified Chirp Scaling Algorithm for Ultra-High Resolution Spaceborne-SAR

Journal of Physics Conference Series ◽

10.1088/1742-6596/2083/3/032048 ◽

2021 ◽

Vol 2083 (3) ◽

pp. 032048

Author(s):

Tao He ◽

Pengbo Wang ◽

Jixiang Ma ◽

Xinkai Zhou ◽

Lingling Xue

Keyword(s):

High Resolution ◽

Phase Error ◽

Equation Model ◽

Synthetic Aperture ◽

Signal Spectrum ◽

Integration Time ◽

Range Cell ◽

Range Cell Migration ◽

Range Equation ◽

Chirp Scaling Algorithm

Abstract The hyperbolic range equation model (HREM) and equivalent squint range model (ESRM) are applied in traditional chirp scaling algorithm (CSA). However, these range models cannot describe the satellite range history in the high-resolution case accurately because of the long azimuth integration time. The non-negligible phase error caused by this will lead the targets distort. In this paper, a modified chirp scaling algorithm (MCSA) is proposed by introducing a novel high-precision range model. A more accurate signal spectrum is calculated through it. Then, the modified chirp scaling factor, range compression filter, range cell migration correction (RCMC) filter and azimuth compression filter can be derived based on this signal spectrum, and the focused target obtained at last. Finally, the experimental results, to validate the proposed algorithm, adopted by the sliding spotlight synthetic aperture radar (SAR) simulation are provided.

Download Full-text