Satellite method identifies Dhofar frankincense with 93.7% accuracy

A new satellite-based method has identified frankincense trees in Dhofar with an overall classification accuracy of 93.7 per cent, raising the prospect of using remote sensing to monitor one of Oman’s most important natural and cultural resources across much larger areas than conventional field surveys.

The study, published in the peer-reviewed journal PLOS One on August 13, developed a spectral “fingerprint” for Boswellia sacra — the tree that produces Omani frankincense — and tested it against high-resolution WorldView-3 satellite imagery at Wadi Dawkah in Dhofar.

The research was led by Associate Professor Yaseen Ahmed Al-Mulla, Director of Sultan Qaboos University’s Remote Sensing and GIS Research Center.

Rather than simply identifying vegetation, the method was designed to distinguish frankincense trees from other plants growing in the same arid landscape.Using a technique known as Spectral Angle Mapper, researchers achieved an overall classification accuracy of 93.7 per cent.

The study found that a conventional vegetation index was less effective because it could not reliably separate frankincense from surrounding vegetation.Researchers also tested three artificial intelligence-based detection models to determine whether individual trees could be identified automatically from satellite imagery.

The best-performing model, known as Single Shot Detector, recorded precision of 0.83 and recall of 0.93, matching 701 trees during the validation exercise.The 701 figure should not, however, be interpreted as the total number of frankincense trees at Wadi Dawkah.

It represents matched detections used to assess the model’s performance.Wadi Dawkah forms part of the Unesco-listed Land of Frankincense, alongside Al Baleed, Khor Rori and Shisr. The wadi is one of the principal landscapes associated with Boswellia sacra and Oman’s centuries-old frankincense trade.

The potential significance of the new method lies less in a single accuracy figure than in its ability to make frankincense monitoring more scalable.Traditional surveys require researchers to cover large and often difficult terrain to identify, locate and assess trees.

Satellite-based mapping could eventually complement that work by helping authorities identify changes in distribution, target field inspections and compare the same landscapes over time.