Demand-based Placement of LDACS Ground Stations to Achieve RNP 0.3 Accuracy for APNT

Abstract

Regions with dense air traffic has lower separation between aircrafts to maintain the throughput. Terminal area generally requires high throughput and some of the airports need to maintain 3− nmi separation between two aircrafts. To provide 3− nmi separation RNP 0.3 is required. In this paper we propose two possible ways to fulfill RNP 0.3 NSE requirement using LDACS as an alternate system. The first way is to use LDACS in standalone configuration and the other way is to use a hybrid configuration, where position solution is obtained using LDACS combined with DME.The results show that both the proposed methods, standalone and hybrid configuration fulfill RNP 0.3 NSE requirement. Where standalone configuration is more accurate than hybrid, due to the low ranging error of LDACS system. For our analysis the surveillance data for terminal area of Munich and Frankfurt airports were used. In standalone configuration 5 LDACS stations for Frankfurt and 6 LDACS stations for Munich are sufficient to fulfill RNP 0.3 NSE requirement. In hybrid mode both Frankfurt and Munich only need 3 LDACS stations.

Feasibility Demonstration of Terrestrial RNP with LDACS

“…For the purposes of modeling position-domain errors we only consider data collected inside the footprint of the ground stations. This is in line with the concept of operations for LDACS as a pseudoranging system, as discussed in [5] and [12]. For modeling range-domain errors, this consideration is different, as geometry does not play a role in the collection of the pseudorange measurements themselves, only in the computation of position.…”

Satellite selection in the context of an operational GBAS

“…Example plot of 1 day of approaches towards Frankfurt Airport, taken from Kumar et al [Color figure can be viewed at wileyonlinelibrary.com and www.ion.org]…”

Placing LDACS-based ranging sources for robust RNP 1.0 accuracy en-route

“…The lack of robustness is best illustrated in Figure 1. The claim that the DME infrastructure can provide RNP 1.0, as modeled in [1] and [2], assumes that all measurements are available and fault-free at any given time. In order to account for an ability to cope with dropped or faulted measurements we propose analyzing the performance of the DME network in a leave-one-out fashion.…”

“…On the contrary, it is conceivable that APNT systems would not require specific technologies, but instead accommodate many different technologies are hybridized into one modular position solution [6]. One particular instance of hybrid modular APNT that has received attention in the past is the hybridization of DME with the L-Band Digital Aeronautical Communications System (LDACS) [2]. The LDACS signal has been demonstrated to support terrestrial ranging with an accuracy greater than that of DME [7] and can be conservatively modeled with a Gaussian distribution of standard deviation 20 m (2σ) [7].…”