Before the Storm: How Cal Poly, the City of Pismo Beach, and IFT Are Mapping the Shell Beach Bluffs
Ahead of a forecast strong El Niño, students in Cal Poly's Applied GIS course, the City of Pismo Beach, and Inspired Flight Technologies are capturing a high-resolution baseline of the Shell Beach bluffs with the IF800 Tomcat and IF1200.
Coastal bluffs on the Central Coast change naturally over time, and the City of Pismo Beach keeps a close eye on the stretches of Shell Beach near public infrastructure. This winter, NOAA's Climate Prediction Center expects a strong El Niño to continue through the 2026-27 season, a pattern that can bring bigger surf and heavier rain to the Central Coast.
For the City, that raised a practical question: How can Pismo Beach best document changes in the coastline?
A Class Project With a Real Client
The project started at a meeting of the San Luis Obispo GIS User Group, a local network of GIS professionals from government, academia, and private industry. There, Michelle Baragona, GIS Analyst with the City of Pismo Beach Public Works Department, mentioned to Cal Poly's David Yun and Russ White that she planned to fly her own drone over the city's bluffs before the storms arrived.
“I wanted to go out and take some before and after photos of the bluffs, just in case there's some major damage, especially to any of our infrastructure, so we have the documentation to say this came from the storm.”
Yun saw an opportunity. He teaches NR 4418, Applied GIS, at Cal Poly, where students take on a real project for a real client each year. This year, that client is the City of Pismo Beach.
“El Niño is coming, and there are some spots that might get eroded,” Yun said. “Wouldn't it be nice to actually quantify before the storm, and quantify after the storm if anything has changed?”
Russ White, Data and GIS Specialist at Cal Poly’s Robert E. Kennedy Library, highlighted that students have access to the ESRI ArcGIS Drone2Map mapping software to process 2D images into 3D point clouds, textured meshes, or orthophoto products. Dr. Marc Horney joined to lead LiDAR data collection, and IFT came on board to provide aircraft and high-resolution camera payloads.
Choosing the Survey Sites
Michelle worked with the City's utilities and facilities managers to select survey sites near city infrastructure. The first is a bluff section at Memory Park, next to
the park and the street. The second is a bluff above a city sewer lift station. Both sites sit largely on city-owned land, and flight routes were planned to stay over city property.
Photogrammetry vs. LiDAR
Beyond its value to the City, the project is testing a question many agencies face when building a monitoring program: how close can high-resolution photogrammetry get to LiDAR? To find out, IFT flew the same flight plan twice with the IF800 Tomcat, first with the Sony LR1 and then with the Sentera 65R, to see how each camera performs against the other. Dr. Horney’s Cal Poly team flew its IF1200 with a YellowScan Explorer LiDAR sensor to produce the reference dataset, and the City captured reference photos with its own consumer-grade drone. At the controls of the IF1200 was Emma Allen, a Cal Poly graduate student and flight crew lead.
From there, students Katie Duff, Isabelle Tamashiro, Kaelyn Kubota, and Greg Goyne will process the imagery into point clouds and compare the photogrammetry results against the LiDAR. Yun summed up what's at stake: “If there isn't much difference, getting a good camera is less expensive than getting the LiDAR device. If there is a significant difference, we know a LiDAR device is needed to quantify volume.” Either way, the comparison gives the City, and other public agencies monitoring similar coastlines, a clearer picture of what level of equipment the job actually requires.
Why the Baseline Matters
When a storm damages public infrastructure, a city has to show what was there and that the storm caused the damage. In the past, Pismo Beach documented bluff loss with traditional surveys and inspected the ocean side of the bluffs from a kayak, and the City only recently began adding drone footage to its satellite imagery. A georeferenced, high-resolution survey captured weeks before the storms gives the City a far more precise record to work from.
“If critical infrastructure is damaged, the City can use this baseline for requesting state and federal emergency relief aid,” Baragona said. The City can also share the data with geotechnical engineers to help design site improvements if there is major damage, and the images will support public outreach and record-keeping.
Coming Next Issue: The After Captures
“This baseline data will allow the City to confidently monitor the changing coastline in these areas without relying on outdated, low-resolution satellite imagery,” Baragona said. “This will allow the City to make informed decisions about the future of the site and its infrastructure to improve public safety and enjoyment.”
Once the storm season passes, the team plans to fly the same sites again and measure what changed. We'll share those after captures, and what the photogrammetry and LiDAR comparison reveals in the next issue of the IFT Quarterly Magazine.
For IFT, the project is a chance to support Cal Poly students and our own Central Coast community with the same platforms surveyors and public agencies rely on every day.
