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Every Millimeter Matters

Published Date
Author Trimble Real-Time Networks

Keeping tabs on the Pacific coastline in Long Beach

Situated on an active fault line, the City of Long Beach in California is well aware of the potential hazards they face each and every day. Not only does the city have seismic activity to keep an eye on, it is also responsible for bringing in 82.3 million metric tons of goods through its port. With life safety and a connection to the country’s economy, Director of Survey for Port of Long Beach Kimberley Holtz, PLS, PG, Geodesist, and Geologist for the Long Beach Energy Resources Department has to watch for the slightest signs of movement in the earth’s crust.

Kimberley oversees the Long Beach Virtual Reference Station (VRS) network, which delivers precise data 24/7/365. 

One of the main challenges encountered when setting up the Long Beach VRN was creating a solution that would allow external users to access their corrections data. Wanting to keep the data secure, the city implemented a firewall to keep random IP addresses from pinging into their network. But, this firewall also meant licensed users couldn’t get in either. Working hand-in-hand with Trimble, a mirrored system was set up that allows Trimble Network Management (TNM) to operate simultaneously on both sides of the firewall providing precise data to the city and precise data to all other users. This custom solution is a win-win for the city, who retains their security measures and the users who gain access to top notch GNSS corrections data. The process is further streamlined by running on Trimble’s Pivot software platform that provides a robust and scalable framework to deliver exceptional system performance, enable flexibility in configuration and reduce the cost of operations.

Long Beach’s VRS network comprises 14 Trimble NetR9 Global Navigation Satellite System (GNSS) base stations. Each station is housed in either a building or a standalone cabinet along the shoreline. Solar-powered stations keep the base stations running where hardwiring is not an option. While the NetR9s have proven durable, a 2020 upgrade to the Trimble Alloy GNSS reference receiver will increase the durability with its rugged IP68 housing and internal Wi-Fi.

An on-ground team keeps tabs on the receivers and manages all the hands-on maintenance, but TNM takes care of all the back end work, freeing up Kimberley and her team to focus on port operations.


To learn more about how the City of Long Beach, Long Beach Energy Resources Department, Long Beach Public Works and the Port of Long Beach Survey Department work together to gain an added measure of security for their city and the people and commerce they are responsible for, read the article published earlier this year by American Surveyor. The article discusses the network in more detail and how they are helping keep the geodetic profession alive. Be sure to watch the video interview with Kimberly at the end of the page to listen to her explain and demonstrate the ease of working with Trimble GNSS reference receivers. As an added bonus, American Surveyor also spoke with the State Cadastral Surveyor of Utah. At the end of the City of Long Beach article, you’ll gain some insight into how the 136,583 square mile Utah Reference Network is modernizing its network.