NIROS planning tool


FLYING AND THE ENVIRONMENT	BASICS	FLIGHT TRACKS	ACTIVE ENVIRONMENTAL PROTECTION	LINKS

Arrivals and departuresFlight levelsSpeed and bankNIROS planning toolLegal frameworkAircraft types

NIROS planning tool

Arrival and departure routes are planned in accordance with the standards published by the International Civil Aviation Organisation (ICAO). The ICAO has published the PANS-OPS document which comprises approximately 1,000 pages and deals almost exclusively with factors such as obstacles, topographic features, radio navigation facilities, etc.

In order to consider noise exposure in its planning process, DFS operates NIROS (Noise Impact Reduction and Optimisation System), a planning tool to optimise standard instrument departures routes (SIDs) with regard to their noise exposure for the population. NIROS aims to determine minimum noise by basing routings on scientific research. NIROS was originally developed at the University of Applied Sciences in Darmstadt and is now used and is regularly updated and improved by DFS.

Working method of NIROS
NIROS simulates the departure of aircraft which use a flight management system (FMS) on a standard departure route. The speeds of individual flight phases are used to calculate how much time the aircraft requires to cross a certain spot on the ground. This is then used to calculate the duration of the noise at this spot. When calculating noise transmission and the resulting noise immission level, it is also possible to consider variable atmospheric phenomena.

The noise immissions calculated by NIROS (equivalent continuous sound level, or Leq for short) are later weighted against the population density of the surface that the aircraft flies over. This leads to a load parameter for each surface element. The surface elements or raster cells have a size of 100 x 100m. The integration of the load parameters results in a disturbance factor for the entire area considered, known as the performance value.

Results of the noise exposure modelling
Each NIROS calculation results in a performance value and three maps:

Distribution of population
Distribution of sound levels
Distribution of weighting (distribution of load parameters)

For more detailed analyses, it is also possible to print the NIROS results on topographical maps.


07/06/2011	PRINT