Dr Ir Alain MULS

Full Professor     +32-2-44-13936     Academic details

Research projects


One of the overal objective of the project is to monitor and evaluate the Galileo PRS quality of service (navigation performance, security performance, robustness) during the two-year period, along with the progressive deployment of the Galileo system, assessing access control and all related operational PRS procedures, analyzed with respect to the available functionalities and robustness, throughout laboratory and on the fields tests in user oriented scenarios.


The aim of the 3PfD project is on the one hand to help the PRS Participants’ CPA to fully comprehend the PRS service and how to interact with the System and on the other hand to perform real operational tests of PRS during measurement trials and campaigns. The project targets defence, police and security forces as main User Communities (UCs) and will increase PRS awareness amongst interested UCs supporting a stepwise up-take of PRS.


The MoNIfly project (Mobile-Network Infrastructure for Cooperative Surveillance of low flying drones) proposes a surveillance and control system of ‘open category’ drones based on Mobile Network Infrastructure.


Galileo is Europe’s own Global Navigation Satellite System (GNSS) system, providing a highly accurate, guaranteed global positioning service under civilian control. The fully deployed Galileo system consists of 27 satellites, positioned in three circular Medium Earth Orbit (MEO) planes at 23 222 km altitude above the Earth, and at an inclination angle of 56 degree with respect to the equator. The Galileo Public Regulated Service or PRS is an encrypted navigation service designed to be more resistant to jamming, involuntary interference and spoofing. It is similar to other Galileo services, but ensures continuity of Service (CoS) to authorised users when access to other navigation services is denied, increases the likelihood of continuous availability of the Signal-in-Space (SiS) and provides an authenticated Position Velocity Timing (PVT) service. The Binary Offset Code (BOC) modulation used by the PRS navigation signals move the signal power away from the band centre, thus offering the potential for better code-tracking accuracy and multipath rejection. The high BOC modulation order of the PRS navigation signals, and the L1A signal in particular, are sensitive for false tracking of correlation peaks. This phenomena has been observed during PRS testing done by European Space Research and Technology Centre (ESTEC) in limited data sets. In order to obtain better insight in the environmental conditions and the correlation channel causing these false locks, this BE–Galileo PRS In Orbit Validation Service (BE-GPIOS) project proposes a methodology to benchmark the PRS signal tracking and PVT performance in operational environments. A second objective of the BE-GPIOS is to get a better understanding of the PRS navigation services, the security concerns related to the key management and key distribution, the concerns and expectations that Belgian users and user groups have. The aim is that Royal Military Academy–Department of Communication, Information, Sensors & Systems (RMA-CISS) will become and act as a center of competence for the Belgian Government and public entities who have interest in the use of the PRS navigation service for their operational use.


The GNSS Signal-in-Space (SiS) Integrity Assurance project is addressing the underestimated and hazardous effects of external EM interference signals on GNSS SiS integrity, in safety critical air navigation applications.


Development of Earth observation SAR-based tools to improve surveys required for humanitarian demining. Analysis and modelling of long term mechanisms and processes related to potential indicators of contaminated areas through exploitation of time series of ERS and ENVISAT archives will be performed and validated in Croatia. The idea is to differentiate human-induced effects from natural ones by exploiting the combination of the amplitude and phase changes of the signal. The same tools could be used for food security applications. The project could serve as a feasibility study for using stacks of free Sentinel-1 images.

EUREF 2008

Organisation of annual EUREF conference (june 2008)


De evolutie in de topografisch meetinstrumenten voor driedimensionale puntpositionering evolueren naar de integratie van twee complementaire technieken (totaalstation en GPS) elk zijn eigen voordelen en beperkingen. Als resultaat hiervan dienen de klassieke calibratie procedures voor theodolieten aangepast te worden voor de nieuwe generatie totaalstations. Logischerwijs heeft het GPS deel van deze theodolieten een heel specifieke testprocedure nodig. De procedure voor de calibratie van de electromagnetische afstandsmeter en de calibratie voor de hoekmetingen moeten eveneens bestudeerd en zo nodig aangepast worden. Bovendien wordt de software ingebouwd in het totaalstation vaak ten onrechte genegeerd bij calibratie van het instrument. Bepaalde fouten worden geïntroduceerd door limieten inherent aan de implementatie van bepaalde software algoritmes, ook bij het verwerken van ruwe satellietgegevens. Deze fouten zullen zich voortplanten in elke verdere berekening met puntcoördinaten, zoals bijvoorbeeld de berekening van voorwaartse en achterwaartse insnijdingen, berekening van oppervlakken, .... Een grondige test methodologie van de ingebouwde software is daardoor een noodzakelijke ontwikkeling.

Het voorstel beantwoordt aan de nood voor een grondige studie en suggesties voor procedure en uitbouw van een laboratorium nodig voor de calibratie van satelliet totaalstations. Dit type instrumenten belooft immers populair te worden in de topografische wereld, waar kwaliteitscontrole een belangrijk aspect is.


  1. A Muls. From GPS to Galileo: the need for encrypted navigation services. Royal Military Academy, April 2014.
  2. A Muls. The Public Regulated Service of the European Galileo navigation satellite system. Royal Military Academy, June 2014.
  3. A Muls. Objectives of BE-GPIOS and results of the PPTI-1 PRS measurement campaign. Eu restricted report, Royal Military Academy, March 2013.
  4. Alain Muls. Reële tijd geleiding van vectoren door differentiële satellietwaarnemingen. Toepassing op de precisienavigatie van landvoertuigen en schepen. PhD thesis, Katholieke Universiteit Leuven, 1994.