Smart Cities - What's Underground?

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I release the weekly LiDAR 101 newsletter to review main takeaways from panel discussions hosted on Clubhouse and events and news specific to LiDAR technology and automation. I invite anyone interested in LiDAR technology to join us in the LiDAR Technology Club on Clubhouse.


3/15/2021 - 3/23/2021 | Main Takeaways from LiDAR 101 Panel Discussions

Intro to LiDAR Technologies

With multiple SPAC IPOs and a drop in price enabling mass adoption: Light Detection and Ranging Technologies, or LiDAR, are favored by industries pursuing automation. Lidar gives devices like cars, robots, and drones "eyes" with sensors to enable computer vision.


If you're new to LiDAR, don't sweat it - at the pace of this rapidly developing technology, there is constantly further information and potential for innovation to digest. For an introduction to LiDAR technology, I recommend reading the first newsletter for an in-depth look at this emerging technology landscape: LiDAR 101 Weekly Panel Takeaways. 


Smart Cities: What's Underground? 

It turns out the final challenge for cities searching for an equitable "Smart" transformation may not be what's above ground, but understanding what lies under the city. Underground mapping has the benefit of helping municipalities not only enhance infrastructure, but also avoid the consequences of not understanding what's underneath the city is both expensive and unsafe. In the US, an underground utility is damaged every minute, resulting in as much as US$1.5 trillion indirect costs to the US economy annually. According to the Federal Highway Authority (FHWA), missing or inaccurate information about the location of underground utilities is a leading cause of highway construction delays.


In Singapore, the Urban Redevelopment Authority plans to have a master plan of Singapore's underground spaces. It will be released as part of the next Master Plan guiding Singapore's development in the medium term. According to the URA, the overall goal is to enhance mapping accuracy and reduce underground development costs. 


Besides understanding underground infrastructure, mapping of pipe networks has been an initiative with operational and technical obstacles. Pipes have overlapping infrastructure elements typically placed at different depths. Simultaneously, pipes and cables in the underground networks consist of varying sizes, segments, and spans over large geographical areas. These factors attribute to using 3D mapping and modeling for a more accurate view of the complex infrastructure.  


Sensor fusion has enabled the potential to combine above-ground mobile LiDAR with underground GPR detection. Using both technologies helps democratize underground 3D mapping initiatives that are cost-efficient and resolve cities' safety threats. Public advocacy has increased to understand where utilities and other underground infrastructure are located, helping to accelerate cities to create a subsurface digital twin at the municipal, regional, and national levels.



Subsurface & 3D Mapping: New York City


While underground infrastructure poses a national threat, the threat is particularly huge for New York City. Construction crews face the prospect of rupturing gas lines, hitting water mains, or shorting a generator. This challenge is exacerbated by events like hurricanes or flash floods, such as the many citizens and two hospitals left without power from Hurricane Sandy


Looking at the New York City Lidar scan from 2017, LiDAR data is used in a variety of ways to continuously improve the city and mitigate environmental and construction threats, saving money and avoiding safety liabilities in the process. Derived datasets can be used to analyze coastal storm and sea-level rise inundation, flood risk assessment and mitigation, and green infrastructure and tree canopy planning.



Bathymetric LiDAR + New York City's Shorelines

Bathymetric LiDAR uses a green light sensor to capture bathymetry, which elevates the ground below water. Unlike near-infrared, using a green wavelength enables LiDAR technologies to penetrate water. Greenlight LiDAR flights flew over NYC between July 4th, 2017, and July 26th, 2017, to capture the shoreline during low tide and good water clarity conditions.  

 Shorelines along the Hudson and East Rivers tend to drop in elevation so quickly from the shoreline that it is unlikely that the green LiDAR sensor would have captured enough data to warrant flying in these areas. Bathymetric LiDAR is best utilized where the water's perceived to be shallow enough to capture valuable data. In NYC's Greenlight flights, this included: 

  • Long Island Sound Coastal Ways 

  • East River between the Bronx and Queens 

  • Upper New York Bay Coastal Ways 

  • Staten Island Coastline 

  • Jamaica Bay 

  • Atlantic Coast (south Queens) 



How will autonomous vehicles shape transportation for persons of all abilities? 

While safety is synonymous with autonomous vehicles, there are many real-life application gaps for the future of self-driving cars and urban mobility. The implications are enormous for the elderly and persons of all abilities who are already at higher risk for traffic and pedestrian accidents. Criticisms against self-driving vehicles often cite a lack of regulation and continuous accidents plaguing self-driving models like Tesla (who famously doesn't use LiDAR) to be investigated in the UK.  


Other obstacles in the real-life application of self-driving cars include autonomy's consideration for persons of all abilities. Just because a vehicle is autonomous doesn't contend that a vehicle is continuously equipped to improve disadvantaged drivers' care. From special requirements for disabled drivers to needing help navigating from their door to their doctor's appointment, autonomy isn't a solution for replacing human interaction for all transportation forms. Even if a vehicle can shield traffic accidents, it is incapable of providing medicine to a sudden Diabetic coma or stopping an epileptic attack, for example. Human interference and caretaker responsibilities should be considered when planning autonomous mobility solutions for persons of all abilities. 



Continue the Conversation: LiDAR 101 on Clubhouse with the LiDAR Technology Club


Contact the Author: 

Alexandra Reynolds, CMO/Co-founder at Metrolla 

[email protected]


About Metrolla

Metrolla was founded in 2020 to solve data-offload limitations for companies using LiDAR technologies. With Metrolla, companies using LiDAR can build distributed data pipelines and apply machine learning or AI to their environments on the fly. Additionally, Metrolla can perform object and anomaly detection at the edge and provide automated event notification. Using Metrolla, organizations don't need to rely on a team on the ground to manually review environments, retrieve sensitive data, or post-process and coordinate data with other sensors. Metrolla empowers teams to automate collecting intel quicker and more accurately, allowing real-time live data collection to achieve automation. Visit or connect with us on LinkedIn or Twitter for more information.