At this hour, Wil Maheia and the Belize Territorial Volunteers are making last-minute preparations for the first day of a venture that has never been embarked upon in Belizean history. They will attempt to clear the Belize/Guatemala border using machetes. Maheia says that BTV and he have made realistic contingency plans to ensure that they do not enter and infringe on Guatemalan territory by having the support of extensive maps, compasses, and GPS devices.

The GPS is one of the most high-tech instruments that they can use to track their location, but even this equipment has its limitations. Today, Ian Gillett, who is an experienced surveyor, and who has been studying GPS for years, explained to us just how it works, and what those limitations are:

Ian Gillett - GPS Expert
"GPS is basically a navigational system. It is system built by the US Defense System, it has 24 satellites that are in orbit and they circle the earth 2 times per day in 12`hour sequence. They operate basically with atomic clocks. What we go in the stores and buy are receivers. The average person can go and buy a handheld receiver. Just as with any other thing - the cheaper the receiver the less accurate it is. The more expensive the receiver the better accuracy you get from a receiver. For a GPS to function properly you need a fair view of the sky. GPS are used only outdoors. Limitations occur when you are in heavy forested area and when you are against tall buildings. Once you are against a tall building or a heavy forested area and you do not have a direct line of sight between the receivers that is in your hand or satellite then you have a decrease in accuracy or basically a limitation and then the accuracy is thrown out. The average accuracy of a handheld GPS is within 10-30 meters. Accuracy is something that is calculated versus a known position. You must know a point in order to determine how accurate you are in proximity to that location."

Daniel Ortiz
"That known point - it has to be something that is already established?"

Ian Gillett - GPS Expert
"Right that position had to have been established, it had to have been observed and calculated and accepted and then you can then determine the accuracy of a GPS versus that known point."

This evening, Wil Maheia spoke to 7News and told us that he will be accompanied by some very knowledgeable former security personnel and land surveyors who are highly experienced in the country's maps and terrain. He also told us that tomorrow's location is under clear skies, and in the sight of at least 10 of those global positioning satellites which Gillett spoke about in the interview. We hope to ask him tomorrow in person about his plan for those places along the border where there are thick canopies, as described by the BDF Commander yesterday.

Channel 7