6th archaeological campaign at Mleiha, Sharjah (UAE)
The Royal Museums of Art and History, Brussels.
A Belgian team works at Mleiha since 2009. The 2014 campaign (20/11-18/12/2014) was mainly a study campaign on the architectural remains, finds and ceramics that are kept in storage at the site. The field activities were limited to surveying and to the continuation of the excavation of two monumental tombs that had started the previous year. At the same time, a drone for aerial photography was tested in various weather conditions and environments. The 2014 expedition is supported by the Royal Museums, the FWO (Research Foundation - Flanders) and the IAP VII (Greater Mesopotamia: Reconstruction of its Environment and History) and works in close collaboration with the Directorate of Antiquities of the Emirate of Sharjah, headed by Dr. Sabah Jasim. The expedition is directed by B. Overlaet (RMAH), members and collaborators of the 2014 team were E. Haerinck (senior archaeologist), B. De Prez, P. Pincé and L. Van Goethem (archaeologists), H. Steenbeke and M. Coppejans (architectural reconstructions) and Patrick Monsieur (amphora identifications).
Fig. 1. The 2014 Belgian field team and local workmen.
During the first four years a large surface with 7 monumental tombs and 4 more modest pit graves (zone P) was excavated on the eastern fringes of the site (Fig. 2). In 2013 a ground penetrating radar survey targeted its surroundings, extending the research area eastwards up to the modern wadi. A series of tombs with monumental square superstructures were revealed and the excavations documented the presence of modest pit tombs between the clusters of monumental tombs (Fig. 2). The two monumental tombs excavated in the 6th season are located on the low mound Z. Both tombs were looted but still produced interesting finds such as Rhodian amphora fragments, Mesopotamian glazed luxury vessels, various types of gold beads and alabaster vessels from Yemen. All these point to a date in the first half of the 2nd century BCE. They illustrate the importance and the role of Mleiha on the Arabian trade routes and contribute important elements for the chronology of the Oman peninsula.
Fig. 2. Drone photography of graveyard area AV with the Belgian excavations.
Drones and aerial photography
Drones are ideal for oblique overviews of excavations, vertical photography in view of mapping and measuring and for more general surveying purposes. Drones can replace the use of ladders and scaffolds and of kites or hot air/helium balloons on many digs. Professional drones remain expensive and complex, however, and demand a skilled and well trained pilot, often seconded by someone to operate the camera. In recent years, archaeologists have therefore started to experiment with low budget recreational drones fitted with lightweight cameras. Commonly reported problems of these early attempts were, however, a limited flight time due to battery capacity, low quality photography and particularly the inability to use the drone in anything but very light winds. The latest generation of “consumer drones” have become increasingly user friendly and most of these problems have been solved. We opted to experiment with a standard version of a “DJI – Phantom 2” quadcopter mounted with a 12 MP camera on a damped 2D gimbal for stability. The camera can be tilted in flight between a horizontal and vertical position. An OSD or “On Screen Display” module streams the camera view and technical and navigational data to a monitor on the remote controller. This makes it ideal for low altitude aerial surveys in accordance with aeronautical regulations (below 50 meter). The relatively small drone necessitates video piloting (FPV, First-Person View) via the monitor when surveying larger areas since it is impossible to keep track of it with the naked eye.
Fig. 3. The drone in its transport case and mounted on a backpack.
The drone is kept “flight ready” in a custom made protective transport case at the excavations and can be made ready for flight within minutes. It can thus be used on the spot without delaying any of the excavation activities.
During the 2014 expedition at Mleiha trials were made in different environments and weather conditions. Flights were made above the excavation field in the wadi plain and during surveys around the excavations and on the nearby Jebel Fayah mountain ridge. Surveying flights above the wadi during the early morning hours produced excellent shadow marks. Flights could normally continue for several hours until stronger thermals started to develop and “dust devils” started occurring. The general experience was very positive, however. The drone could be flown in moderate to strong winds and performed well in all conditions. With a maximum flight speed of 15m/s. (54 km/h.) it can even counteract gusty winds.
Fig. 4. Subtle shadow
marks of very low mounds with monumental tombs in area AV. The oblique view
emphasises the effect of the shadows.
Drone surveying in the mountains demands a somewhat different approach. The drone was mounted on a backpack and used from various points near the top of the Jebel Fayah (see fig. 1). Flights were made early in the morning and halted once thermals, accelerated by their path across the mountain, reached vertical velocities of more than 1m/second. In a mountainous environment is keeping visual track of the drone essential in view of the effect of local winds and turbulences on the flight path close to the relief. Turbulences and thermal activities can be strong and develop rapidly. In general, these first trials on the Jebel Fayah were all together positive. The technical equipment was effective and allows covering large zones in limited timespans. During these first trials, two structures - likely to be a musallahs or prayer area - were located and documented. A general aerial survey of the mountain area could supply important data to identify and protect local archaeological and historical heritage.
Fig. 5. Mountain top of the Jebel Fayah with a square structure, possibly a musallah.
Fig. 6. A Dust Devil, a strong thermal sweeping up the sand, moves over the excavations.
Fig. 7. View from Mleiha towards the Jebel Fayah.