Merging Terrestrial and Hydrographic Scanning

arc bridge set upBackground

Back in the late 1980’s John F. Sawyer saw the need for a surveying services company that could provide accurate hydrographic surveying and quantity calculations. Mr. Sawyer had a background in dredging and in 1989 Arc Surveying and Mapping (Arc) was born. The company is family – owned and operated with three brothers running the day – to – day operations.

A good portion of their work is hydrographic – related. They perform work in all of the Caribbean Islands and have completed projects from Panama to New York. Arc currently has a main office in Jacksonville, Florida, with satellite offices in Memphis, Tennessee and Melbourne, Florida.

John K. Maffett, PSM began his career with the City of Jacksonville, FL survey section in 2000 as a drafter. John came from a mapping background and taught himself AutoCAD in high school. He has worked on everything from boundary and topographic surveys to 3D laser scanning and bathymetric/hydrographic projects.

“Within the past five years I have acquired a Bachelor’s of Science in Business Management and a Masters of Business Administration with a major in marketing,” John noted. He is currently a licensed surveyor in the State of Florida and has been working with 3D laser and sonar scanning and all things point cloud related with Arc for the past 10 years.  

John Noted, “The drive to take advantage of innovation, while fully making use of current technology has been key to the success of the company.”

Technology

Arc has been an early adopter of laser scanning and sonar technology. The company originally had a demo of the early Cyrax on a job in Puerto Rico where they were laser scanning the cliff face of the Portuguese dam. They purchased the second Ilris laser scanner in the United States. As technology progressed it was inevitable for Arc to upgrade in order to stay competitive.

John attended SPAR 3D on several occasions to review and choose a new scanner. They were just about ready to buy a new scanner when Riegl USA called. John remembers, “They were located in Orlando and our main office is in Jacksonville, FL. The Riegl sales person came and gave us a demo. We were sold.”

Arc leased the VZ-400 on several occasions for various projects and it worked well. “I like the fact that all hardware and software support is done in house and that they are only a couple hours from my office. I have yet to find a better field – to – finish collection and processing option for terrestrial laser scanning,” John noted.

arc bridge scanner locationToday Arc has a wide variety of underwater survey systems including multibeam and singlebeam sonar, Blueview 3D sonar and a magnetometer. They use a wide variety of software to post process the data including RiSCAN Pro and Hypack for the hydrographic data.

John recalls, “Originally the scanner was mainly used on land for stock piles, quarries, and small topo areas. Working with Riegl I have refined terrestrial collection processes utilizing real time RTK corrections. For the past two years our main focus has been mobile scanning with the VZ-400.”

Arc currently utilizes the VZ-400 coupled with an Applanix POS-MV WaveMaster to mobile scan from their boats and vehicles. About 70 percent of the work is hydrographic. “We have combined the VZ-400 with the Reson multibeam systems to provided simultaneous collection of above and below water data, creating 100 present coverage of all visible features,” John explained.

John continued, “By far, of all the hardware and software collection platforms I have used the Riegl works the best for our applications. If meets our accuracy requirements and is one of the best in the industry. The ease of field collection and office processing makes the system user friendly for even the novice operator.”

Projects

Freeport Harbour

Since 2010 Arc has provided Freeport Harbour Company (FHC) with topographic and hydrographic surveying services in support of FHC port expansion projects.  Freeport Harbour is located approximately 50 miles east of West Palm Beach Florida and is a trans-shipment facility, accepting the largest container ships in the world.  The entrance channel and container berths are approximately 65 feet deep.

Safety and coordination with the Harbour Master, pilots, contractors and vessel operations is essential in Freeport due to constant berthing and traffic.  An open berth is surveyed as soon as available and topographic surveys are performed during times convenient to container movement.  In addition to topographic construction layout and as-built surveys, Arc has performed all hydrographic surveys for the port including pre and post dredge surveys.

In 2014 Arc performed a bathymetric and shoreline survey of the entire harbour, adhering to British Admiralty Charting Standards, for upgrading navigational charting and construction purposes.  A fully equipped Arc survey vessel was transported to the island via ferry from West Palm Beach, Florida.  Within 24 hours the survey vessel was offloaded, calibrated and ready to work utilizing a Reson 7101 multibeam swath sounder, a Riegl VZ 400 terrestrial laser scanner, an Applanix POS/MV and an RTK system for tidal measurements. Hysweep was used for equipment configuration, data collection and processing. 

Freeport Harbour is a unique operation as the expansion is never ending.  Bahama Rock Company drills, blasts and excavates the expansion areas utilizing mine-type draglines, shipping the road base quality material to the U.S. mainland.  As a result of dragline excavation, the slopes in expansion areas are extremely irregular.  In order to develop construction plans for container berth expansion, FHC contracted with Arc to survey the entire harbour including the seafloor and shoreline with close detail to slopes.  The object of the detailed multibeam slope survey was to develop a plan to drive corrugated sheeting along the irregular slope and to grout between the sheeting and cavity prone slope, thereby stabilizing future berths.

Raystown Dam

Arc was contracted by Zoppo Construction, Inc to assist with their Baltimore District Army Corps of Engineers (ACOE) project, which among other work items, required replacing the rubber seals of the tainter gate. 

An issue with the mechanical and wire rope mechanism responsible for raising and lowering the tainter gate, as water levels required, caused the gate to bind with the structure guides.  While raising or lowering, the gate would seize causing the operator to raise and lower the gate until it passed the binding area. The binding area was not at the same location during each event causing the ACOE to question the synchronization of the gate lift mechanism on each side of the gate. 

In addition to laser scanning the existing seals and seal footer, Arc scanned the raising and lowering of the tainter gate, continuously recording xyz positions of each side of the gate simultaneously with precisely position synchronized terrestrial laser scanners.  Using this method of simultaneous continuous scanning of the gate in up and down movements, the raising and lowering mechanisms were adjusted to the correct settings eliminating the binding.

Looking Ahead

With an eye to the future, John commented, “Currently the industry leaders in my opinion must be on the cutting edge of technology to stay relative. Arc has always been one of the first in the surveying industry to try new technology and utilize it to our advantage. The combination of conventional surveying, terrestrial scanning, hydrographic surveying, and now drones provide a vast array of tools to increase quality and efficiency.”

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