Surveyor rises to occasion again in Tibet

For the three measurements of the mountain that Bai participated in, correct stationing of the base camp was a must.

"The mountaineering period on Qomolangma every year is fixed, lasting from the end of March to the end of May," Bai said.

"Our survey team must reach the summit during the window period due to the severe weather and the special geographical environment of Qomolangma."

At the peak of the mountain, about every 10 days there is a window of opportunity for the survey team to take measurements when the weather is good, he said.

In their downtime, Bai and other members rested and adjusted and tested the survey equipment.

Despite taking part in three expeditions, Bai has never been to the summit with the surveyors. He said his job was to keep the equipment used on the peak in good order and train team members how to use it correctly.

At another base camp at 6,500 meters, where it usually snowed heavily, Bai said his main job was to instruct his fellow surveyors how to use radar and surveyor's beacon.

During last year's expedition, the equipment used included snow-depth detection radar, a global navigation satellite system receiver and a summit survey maker. Bai said some of the equipment was customized for the expedition.

Measuring Qomolangma took from March 2 to May 29 and involved 53 team members.

Bai said based on the experiences of previous climbing expeditions, last year they paid greater attention to the design of the survey maker to make it easier for the mapping teams. "What's more, the survey maker that we use now is totally made in China, and it is produced in a factory in Changzhou, Jiangsu province," he said.

While multiple surveying and mapping tools were used, the heavier equipment could only be transported by vehicle to 5,200 meters."Higher than that altitude we have to rely on the yaks and porters to carry stuff to the peak," he said.