Extreme GNSS surveying leverages the performance, reliability and flawless operability of CHC Navigation (CHCNAV) receivers
CHC Navigation’s P5 geodetic GNSS receiver on May 27 was used successfully by a Chinese team of surveyors to complete the 2020 Mount Everest Elevation Survey.
This is the first time that a team of Chinese surveyors has climbed the summit of Mount Everest, and it is also the first time that BeiDou-based Chinese GNSS receivers have been used to measure the height of Mount Everest, known in China as Mount Qomolangma.
The Everest Project
To promote research on the Mount Everest elevation and to ensure the scientific character and accuracy of measurements, the Ministry of Natural Resources mobilized the Shaanxi Bureau of Topography and Geographic Information Mapping from the Chinese Academy of Topography and Mapping to plan and implement the measurements of the Mount Everest elevation. China’s National Geodetic Survey Team and its Mountaineer’s Team would undertake the arduous climb.
The plan set out the technical guidelines and required that the Everest Elevation Project be designed to achieve innovative and technological breakthroughs in several areas of research.
The first is to use the BeiDou satellite navigation system to perform GNSS measurements; the second is to use Chinese surveying and mapping equipment to complete the task.
Meeting Harsh Challenges
In October 2019, CHCNAV received a request from the Ministry of Natural Resources to provide GNSS equipment for the 2020 Everest Elevation Project. A dedicated team combining different departments, from R&D to manufacturing, was set up. The team elaborated the specific technical requirements from the National Survey engineers, in particular the difficulties and challenges related to the altitude of Everest.
Measuring the height of Mount Everest, especially the summit, is a challenge, not only for the limitation of the human body in such elevation environment, but also for the performance of the GNSS receiver itself.
At over 8,800 meters, the minimum temperature can reach -45°C and the atmospheric pressure is only 30 kPa (compared to the normal 101 kPa). All the surveying equipment used is exposed to both low temperature and low-pressure constraints.
In addition, the operation of the instruments must be as simple and reliable as possible in such an extreme environment. Surveyors wear thick winter clothing and lack oxygen, making every movement an extreme challenge. Finally, the measurement of the mountain peak must be completed at the first attempt, as re-measurement is impossible.
Military-Grade Solution
To meet these stringent requirements, CHCNAV has provided military-grade GNSS receivers that have passed the most rigorous environmental and reliability tests. The entire solution, from the GNSS receivers to the accessories, has been optimized to ensure mission success from the very beginning.
A wide temperature range of material — supporting an operating temperature range of –45°C to +85°C — were used, including redesigned lithium-ion batteries offering 12 hours of operation even at extremely low temperatures. Also used were antenna cables with a specific compound material to avoid any cracking or signal attenuation.
To ensure reliable operation of the receivers in a low-pressure environment, the GNSS receivers have built-in waterproof and breathable valves to maintain internal and external pressures. The low-pressure tests replicated a 25-kPa environment, corresponding to an altitude of 10,000 meters.
Additional ruggedized reinforcement prevented damage in the event of accidental receiver drop thanks to a robust design to keep the display and connectors safe. Following CHCNAV tests, third-party organizations were commissioned to perform environmental testing and reliability verification, including storage and operating at high/low temperatures, vibration, shock, rain, dust, humid heat, salt and fog.
From November 2019 to March 2020, CHCNAV’s GNSS equipment was supplied to the National Photoelectric Rangefinder Testing Center — under the requirements of the China Academy of Surveying and Mapping — for the most rigorous evaluation. As a result, the company’s GNSS receivers were selected to provide the peak altitude measurements of Everest in 2020.
Reaching the Summit
On April 5, 2020, at the Everest Elevation Survey Expedition Ceremony in Lhasa, CHCNAV officially donated GNSS equipment to the National Survey Team. Both product and technical training was provided to the team.
The 53 members of the first National Survey Team overcame the difficulties related to the environment, bad weather and the additional impact of COVID-19, and conducted a series of measurements on Mount Everest and surrounding areas such as level, gravity and GNSS.
Thirty of the 60 points of the GNSS control network were measured with CHCNAV GNSS receivers, including three of the seven Everest elevation intersection points.
On May 27, the CHCNAV GNSS receivers finally reached the summit and successfully completed the task.
The successful achievement of the Everest elevation measurement reflects the performance of the Chinese surveying and mapping industry, confirms BeiDou as a major part of the GNSS systems, and demonstrates the technical success of CHCNAV as a major player in the GNSS industry.
About CHC Navigation
Founded in 2003, CHC Navigation is a publicly listed company creating innovative GNSS navigation and positioning solutions. With a global presence across the world, distributors in more than 100 countries, and more than 1,300 employees, CHC Navigation is today recognized as one of the fastest-growing company in geomatics technologies.