September 17, 2004
Workers in the forest products industry, government agencies, surveying companies and others who rely on Global Positioning System (GPS) technology in northern Maine will now have more accurate data at their fingertips with the installation of a new GPS base station at the University of Maine at Fort Kent.
GPS base stations are used to correct errors associated with factors such as weather, working under a forest canopy, and accuracy of individual GPS units. These are all common factors when using the navigational system involving satellites and computers to determine the latitude and longitude of a receiver by computing the time difference for signals from different satellites to reach the receiver.
Prior to the installation of the antenna at UMFK, northern Maine GPS users relied on a base station in Orono, for some more than 200 miles away.
"Using the station in central Maine is not as accurate as using one close by," said Jeff Dubis, assistant professor of forestry and the individual responsible for coordinating the base station's installation. "Our base station is up and running and will be used by our students for the first time in the coming weeks."
The base station, which consists of a disk about a foot across located on the roof of Cyr Hall on the UMFK campus, is connected to a computer located in one of the science labs inside the building.
Data from the station is saved on the computer's hard drive and can be downloaded, at no cost, to anyone who applies for, and receives, an access password through UMFK information services.
The station was surveyed by Madawaska surveyor Matthew MacDonald of Madawaska, so its exact location is known.
According to Dubis, comparing coordinates generated by the GPS base station to the actual coordinates will indicate how much signal error there is at any given time. The GPS data collected in the field is then compared to the base station data.
"The assumption is that the error in the field data is the same as the calculated error of the base station. By knowing the base station error, we can then adjust the field data. All GPS data is time tagged, so we know the amount of error at all times," said Dubis.
The most immediate and direct beneficiaries of the UMFK GPS base station will be university students enrolled in programs like the associate of science in forest technology, where GPS technology is frequently used. However, Dubis expects others in the community to benefit as well.
"The installation of this new state-of-the-art equipment will allow us to assist the local community at no charge. People in Aroostook County will now have access to more accurate data," said Dubis.
Individuals wanting to access the GPS base station need to log on the UMFK web site at www.umfk.maine.edu/academics/programs/forestry/gps/. Users will be directed how to obtain password access from that site.