Assessing Levels of Energy Radiation through Differing Conditions
Climate Change is often attributed to greenhouse gases, however, other factors affect the Earth's climate. One example of this is the "Earth's radiation budget". Earth's radiation budget is energy that enters the Earth's atmosphere that is reflected, absorbed or emitted by our planet. If the budget becomes out of balance, it can cause temperature increases or decreases in the Earth's atmosphere.
A team from the Institut de Physique du Globe de Paris (IPGP), a world-renowned geosciences organization, has conducted research in this field. Their research focuses on how differences in surface roughness affect the amount of microwave radiation picked up by satellites.
Comparing Surface Roughness of Snowpacks and Avalanches in the Vanoise Massif Mountain Range
For the research, the team has been concentrating on snowpacks and avalanches in the Vanoise Massif Mountain range. They aim to compare the two satellite observations to assess the effect of the change in roughness when avalanches form using radiative transfer modeling. This is the process that measures radiation from the Sun into and out of the Earth. High levels of sun radiation can cause snow to melt which, in turn, can cause avalanches.
The Vanoise Massif Mountain range is in the Granian Alps, in the Savoie region of France. It is the third-highest massif in France, sitting at 3,885 meters at the summit of Grande Casse. The range is the location of France's first National Park, the Vanoise National Park.
The Mountain Range's Dangerous and Difficult-to-Access Environments
To collect data from the snowpacks and avalanches, the team needed an accurate 3D model of the area. Vanoise National Park is a no-fly zone which meant that UAVs were not an option. Additionally, the team did not want to spend extended periods on the mountain due to the risk of avalanches. This ruled out more time-consuming methods of surveying.
As a result, the team needed an efficient way of mapping the difficult area. They decided mobile LiDAR was the best option and chose to use a ZEB Horizon mounted to a backpack.
Using the ZEB Horizon to Safely Map Avalanches in the Vanoise Massif Mountain Range
The walk and scan method and versatility of mobile LiDAR stood out to the team from IPGP. The specificity of the environment meant they needed to use technology that was easily movable and durable. The backpack solution was essential because it meant that the person carrying out the scan had their hands free to help navigate the tough terrain.
The use of mobile LiDAR meant the team was able to scan the 3000 sq/m area in approximately 2 hours. This ensured that they did not spend too long in the hazardous mountain range, whilst capturing the accurate data they needed.
Creating Accurate Datasets to be Used in IPGP's Research
The scans were processed and the resulting point clouds were integrated in IPGP's research analysis and modeling.
The mobile scanner's ease of use and accuracy meant the scan data could be compared with the data collected from the satellite observations. This is known as ground truth analysis and helps with clarity within the research. The scan data also aids with data calibration which allows for atmospheric effects and obstructions to be considered when analyzing the final data.
The positive outcome of the data has encouraged the Institut de Physique du Globe de Paris to plan additional surveys in this area.