Officials from PTT Exploration and Production Public Co Ltd late Thursday morning brought three drones to join the search for 12 children and their assistant football coach, who have been trapped for days in a flooded cave in Chiang Rai.
The firm’s expert, Thana Saranvetchapan, said the three unmanned aerial vehicles (two large-sized and one small-sized), were each equipped with a 30x optical zoom camera and a heat-detecting device. They are able to take and process aerial photographs and then incorporate the shots into a 3-D map.
The first drone flights taken around noon on Thursday were to survey the two-kilometre radius “Zone A” of the mountain above the cave. Information obtained from the flights will be reported to the search and rescue team to they could better plan their cave-wall drilling, said Thana.
The drones are normally used to explore for petroleum.
One team will oversee a robot equipped with a sonar scanner capable of producing an underwater map, which would be useful to help the human divers working in muddy water, Thana said.
The other team will help with the floodwater drainage, he said. The soft pipes now used to pump out water are not up to the job and so the firm has provided a hard pipe of a radius exceeding 200mm to aid in the drainage at the cave entrance.