The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Publications Copernicus
Articles | Volume XXXIX-B1
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XXXIX-B1, 441–446, 2012
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XXXIX-B1, 441–446, 2012

  27 Jul 2012

27 Jul 2012


P. Molina1, I. Colomina1, T. Vitoria2, P. F. Silva3, J. Skaloud4, W. Kornus5, R. Prades6, and C. Aguilera7 P. Molina et al.
  • 1Institute of Geomatics, Generalitat de Catalunya & Universitat Polit`ecnica de Catalunya, Castelldefels, Spain
  • 2Asociaci´on de la Industria Navarra, Pamplona, Spain
  • 3DEIMOS Engenharia, Lisbon, Portugal
  • 4Ecole Polyt´echnique F´ed´eral de Lausanne, Lausanne, Switzerland
  • 5Institut Cartog`afic de Catalunya, Barcelona, Spain
  • 6Direcci´o General de Protecci´o Civil, Barcelona, Spain
  • 7European GNSS Supervisory Authority, Brussels, Belgium

Keywords: UAV, search-and-rescue, thermal imaging, integrity, reliability, INS, GNSS

Abstract. This paper will introduce the goals, concept and results of the project named CLOSE-SEARCH, which stands for ’Accurate and safe EGNOS-SoL Navigation for UAV-based low-cost Search-And-Rescue (SAR) operations’. The main goal is to integrate a medium-size, helicopter-type Unmanned Aerial Vehicle (UAV), a thermal imaging sensor and an EGNOS-based multi-sensor navigation system, including an Autonomous Integrity Monitoring (AIM) capability, to support search operations in difficult-to-access areas and/or night operations. The focus of the paper is three-fold. Firstly, the operational and technical challenges of the proposed approach are discussed, such as ultra-safe multi-sensor navigation system, the use of combined thermal and optical vision (infrared plus visible) for person recognition and Beyond-Line-Of-Sight communications among others. Secondly, the implementation of the integrity concept for UAV platforms is discussed herein through the AIM approach. Based on the potential of the geodetic quality analysis and on the use of the European EGNOS system as a navigation performance starting point, AIM approaches integrity from the precision standpoint; that is, the derivation of Horizontal and Vertical Protection Levels (HPLs, VPLs) from a realistic precision estimation of the position parameters is performed and compared to predefined Alert Limits (ALs). Finally, some results from the project test campaigns are described to report on particular project achievements. Together with actual Search-and-Rescue teams, the system was operated in realistic, user-chosen test scenarios. In this context, and specially focusing on the EGNOS-based UAV navigation, the AIM capability and also the RGB/thermal imaging subsystem, a summary of the results is presented.