Handheld GPS Data Collector Speeds Marine Surveys for California Firm

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Posted by on December 22, 2004 at 16:41:13:

NEWPORT BEACH, Calif. --(Business Wire)-- Dec. 22, 2004 -- Mapping aquatic habitats is complex, time-consuming work. But thanks to advanced data collection technology and a new handheld collection device from Thales, at least one California company is getting the job done faster and more accurately than ever before.

Coastal Resources Management (CRM), headquartered in Newport Beach, provides private- and public-sector clients with environmental consulting services for onshore and offshore marine-related projects. Among its services, CRM maps and surveys sensitive coastal shallow-water aquatic habitats. The high ecological value of these habitats makes documenting their location and size a critical task for environmentalists.

To survey environmentally sensitive eelgrass beds, CRM uses a two-biologist survey team: a SCUBA diver below the surface and a following kayaker above. Recently, CRM teams began using the Thales MobileMapper(TM) handheld GPS data collector purchased from Galileo Instruments, Inc. According to Rick Ware, president of CRM, the MobileMapper has proved to be an enormous time-saving asset during collection of field data and processing it in the office. "We'd been using a GPS device designed for recreational use," Ware said. "It was easy to use but didn't give us the accuracy we need. Also, we had to spend hours back at the office recording the data we were producing."

Sub-meter accuracy for precision work

With post-processed accuracy under one meter, direct download capability and consumer-like ease of use, MobileMapper lets natural resource professionals find and describe features they want to map and then easily and quickly download the data to a geographic information system (GIS).

On perimeter surveys of eelgrass beds, for example, the CRM biologist in the kayak follows the biologist/diver, who tows a small yellow "pop" buoy. The MobileMapper is typically attached to a clipboard that's tethered to the kayak. "The unit slips overboard once in a while," Ware said. "But it's totally waterproof and it floats, and those mishaps are no cause for concern."

With MobileMapper the kayaker doesn't need to enter waypoints manually. Instead he sets the MobileMapper to collect waypoints automatically once per second. "Because the depths are relatively shallow, usually less than 15 feet deep, there's no error due to the angle of the buoy and the diver," Ware said.

In addition to automatically recording waypoints at pre-set intervals, MobileMapper saves time by calculating polygon areas, thus saving on the need to calculate areas separately with a planimeter. Where vegetation beds are small, a point measurement is entered on the MobileMapper and the diver comes up and provides a site description that can then be attached to the point.

For shallow-water eelgrass mapping along the shoreline, the MobileMapper replaces the time-consuming process of setting a baseline near the shore and mapping the beginning and ending distances of eelgrass at 3 to 10 meter intervals along the baseline. Laying the transect tapes for large projects and surveying along each interval was time-consuming in the field and in the office, where the data would have to be plotted manually on the maps. "Most important, MobileMapper reduces the labor needed for field and data analysis," Ware said.

The GPS waypoints and descriptive features are downloaded onto a computer using the MobileMapper software. GIS SHP files are then developed from the polygon data and overlaid on geo-referenced, high-resolution maps or color-infrared photography.

"We're getting these surveys and the associated mapping done in half the time they used to take," Ware said. "That means we can cover more area more quickly. That's good news for our clients and the habitats."

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