LINA is a current project which is being conducted in cooperation with partners from industry and university. Its aim is to enable satellite navigation technology to be applied for landing phases of civil aviation. Although satellite navigation is being used on a single-system basis for specific phases of flight, its reliability and its accuracy presently are not sufficient to perform landing approaches. That is why a ground-based augmentation system (GBAS) shall be operated as an ehancement. It will allow to increase the integrity, i.e. the ability of the system to detect erroneous operations and in case of malfunction to provide an alert signal. The acronym LINA for this precise landing system accordingly means "Local Integrity Navigation Augmentation".
LINA is being sponsored by the Department of Economics and Technology (Bundesministerium für Wirtschaft und Technologie) in its fourth national aviation research program named LuFoIV.Main contractor is the German company of THALES-ATM at Korntal near Stuttgart. The company Eurotelematik from Ulm and the Technical University of Braunschweig are further partners to DLR in the team.
The DLR is active in this project with two regards. One is to investigate deteriorations of the quality during the propagation of the navigation signals caused by different effects and to estimate the integrity of the position solution. With the second aim, a pre-operative system shall be tested with respect to the required functionalities during some flight trials.
Important work progress will be achieved by the Institute of Communications and Navigation in investigating the main error sources affecting the navigation signals when propagating from satellite to receiver. Main error sources are ionospheric disturbances, interference and multipath effects. The ionosphere being a high altitude layer in the atmosphere of the earth causes irregular delays to signal propagation which have to be taken into account as error sources. Interferences are additional unwanted signals from different transmit sources which do not belong to the navigation system. In contrary to this, multipath signals have their origin from the navigation system but they are also unwanted due to the uncontrolled reflexions at objects close to the receiving equipment.Derived from these investigations on error sources, the integrity to be achieved will be estimated. Basis for the investigations is the usage of the American navigation system GPS (Global Positioning System). In a second step, the capability to improve the integrity figures by using additional signals from the European Galileo system shall be considered.