Assessing earthquake damages with wearable reality capture

Author: Frank Collazo

On Sept. 19, 2017, a powerful 7.1 magnitude earthquake shook Mexico City and the surrounding states. The earthquake caused the collapse of several buildings, killing 369 people and injuring more than 6,000. Damaged infrastructure also included destroyed bridges, roads, and water and electricity utilities. Mexico City was the most affected with 228 deaths and 38 buildings collapsed. More than 800 buildings are in red code, meaning that they did not collapse but will be demolished.

To aid in the recovery, national and local emergency management authorities asked Mexico City-based Leica Geosystems staff to safely document the damage using remote sensing, reality capture technologies.

Reality capture’s role in emergency management

The Leica Pegasus:Backpack and Leica ScanStation P40 were deployed to laser scan and image as many collapsed buildings as possible to document the damages and capture up-to-date maps, photos and plans of buildings and infrastructure.

The Pegasus:Backpack proved to be invaluable as it could quickly, safely and easily capture the inaccessible disaster area in 3D and document entire blocks by foot. The ScanStation P40 laser scanned heavily damaged un-collapsed buildings to do structural analysis. All data for collapsed buildings in the most affected district of Mexico City was captured by two employees in under two hours and processed on the same day. Critical data was captured before debris and rubble were removed and is now a permanent record in the form of ArcGIS-compatible point clouds and panoramic images.

This data is now being accessed online by Mexico’s disaster management agency through Leica Pegasus:WebViewer, Leica Geosystems’ web viewing service that allows users to navigate, analyse and collaborate through the processed images and point clouds.

“With the georeferenced information of the Leica Pegasus:Backpack, we know exactly where every door, alley and window is located. I can now give my crew accurate instructions on where to go and what to expect before they get there. Without the data, disaster management is a complicated process,” said Dr. Armando Aguilar, president of the Commission on Safety and Hygiene and Civil Protection.

All georeferenced panoramic imagery taken with the Pegasus:Backpack is an orderly record of the disaster sites that will aid future forensics investigations. With Pegasus:WebViewer, emergency personal could see on site the exact state of collapsed buildings before debris and rubble were removed. All information captured by Leica Geosystems’ staff was shared and made available to National Civil Protection Agency and local Mexico City government through a webserver for the Pegasus WebViewer .

Accessing GNSS data with the largest reference network

During data collection with the Pegasus:Backpack, the team relied on the new HxGN SmartNet GNSS base stations in Mexico City to immediately process the GNSS data generated by the mobile mapping solution. Thanks to HxGN SmartNet, a satellite positioning service, GNSS data was available in real time and the team didn’t have to wait about 24 hours to download data from the closest Mexico City public GNSS base stations.

“We finished the installation of the first phase of HxGN SmartNet Mexico just before the earthquake. We were very glad to have the base station available in the aftermath of this event for immediate use to our team for Pegasus:Backpack post processing. We are launching the subscription service in the country early 2018,” said Cinthia Salinas, HxGN SmartNet coordinator for MexAm region.

“We are also receiving a lot of concrete interest for developing HxGN SmartNet in Central and South America. We anticipate HxGN SmartNet Mexico will be the first of many HxGN SmartNet stations to be developed throughout Latin America over the next few years,” added Jill Johnson, HxGN SmartNet senior project engineer for NAFTA region.

We express our sincerest condolences for Mexico City, and we keep all of those affected by the earthquake in our daily thoughts.