Earth Observation for the World Cultural and Natural Heritage

The main goal of UNESCO (United Nations Educational, Scientific and Cultural Organization) is to "encourage the identification, protection and preservation of cultural and natural heritage around the world considered to be of outstanding value to humanity" (World Heritage Convention). To date (April 2015), UNESCO World Heritage List consists of 1007 cultural (monuments, group of buildings, sites) and natural (natural features, geological and physiographical formations, natural sites) properties, 46 of them being considered under threat. The monitoring of the sites included on the UNESCO World Heritage List can be performed based on Earth Observation (EO) data. Nowadays, remote sensing is an excellent monitoring tool due to the recently launched satellite missions that enable the acquisition of very high resolution optical data (with an information content similar to aerial imagery) together with a wider offer of spectral bands. Not only the development of remote sensing sensors is impressive, but also the creation of new synthetic aperture radar interferometric (InSAR) techniques that enable the ground deformation/displacement monitoring up to a few millimeters, based on multi-temporal series of synthetic aperture radar (SAR) data. In 2003, UNESCO and the European Space Agency (ESA) signed the "Open Initiative on the Use of Space Technologies to Support the World Heritage Convention" that has the goal to protect, monitor, document, present and share the World Heritage sites. In this context, the term "space technologies" refers mainly to Earth Observation and secondly to other technologies such as navigation, positioning, communication, etc. In accordance with the "Open Initiative", the study aimed at monitoring the Historic Centre of Sighisoara, a cultural heritage site inscribed on the World Heritage List in 1999 due to its architectural and urban monuments that were built starting with the 13th century. The results provide the Romanian National Commission for UNESCO and the assisting responsible authorities a support for informed decisions and may represent the foundation of a pilot monitoring service for the Romanian natural and cultural heritage sites inscribed on the UNESCO World Heritage List. (C) 2015 The Authors. Published by Elsevier B.V.