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NOMENCLATURE
ADS-B = Automatic Dependent Surveillance–Broadcast
API = application programming interface
EI = emission index
EHS = enhanced surveillance in Mode-S
FDR = flight data recorder
LTO = landing and take-off
TAS = true air speed
SSR = secondary surveillance radar
UHC = uncombusted hydrocarbons
ZFW = zero-fuel weight
a = speed of sound
D = aerodynamic drag
\(F_N\) = net thrust
g = acceleration of gravity
M = true Mach number
n = number of operating engines
\({\mathcal R}\) = ideal gas constant
t = flight time
s = distance travelled/arc length
\(T, T_1\) = air temperatures (absolute scale)
W = gross weight
\(W_f\) = design fuel capacity
\(W_{f6}\) = fuel flow per engine
X = required range
\(X_{design}\) = design range
z = flight altitude
\(\gamma\) = ratio between specific heats
1.0 INTRODUCTION
The prediction of environmental emissions from commercial aircraft is generally performed indirectly without the use of actual flight data. Flight data have always been difficult to gather, despite being available from the Flight Data Recorder (FDR), because of proprietary, commercial and legal issues surrounding the ownership and value of flight records. Furthermore, extracting FDR data can be a time-consuming operation which involves the selection of parameters from a very large set (of several hundred), some of which are stored with different sampling rates. Thus, aircraft tracking has long relied on primary radar detection and more recently secondary radar, wherein the aircraft transmits data upon interrogation. Radar tracking is one of the key systems on which flights and emissions inventories are based.
Estimates of aviation emissions are performed by using ‘inventories’, of which several are now available from multi-national initiatives. The three-dimensional global inventory of aviation \(\mathrm{NO}_x\) ANCAT/EC(1), which is now nearly 30 years old, was the first example of indirect monitoring of \(\mathrm{NO}_x\) emissions at altitude dependent on geographical location, by using Air Traffic Control (ATC) data from a number of cooperating airlines. Direct measurements over the North Atlantic flight corridor were taken in the course of a number of other projects as reported by Schumann(2), to investigate, inter alia, the vertical distribution of \(\mathrm{NO}_x\), \(\mathrm{SO}_x\), \(\mathrm{H}_2\mathrm{O}\) and other aviation-related chemical compounds in the atmosphere.
Since then, the market has changed considerably, many of the aircraft...