COMPASS TO SATELLITE
By Fred C. Hutchinson, BA, NSLS, CLS

 

Knowing where you are in the world or where you want to go has always been important to the traveller, land owner and surveyor. The early explorers and navigators took advantage of the earth's magnetic field by using the compass to determine direction. The stars, sun and moon were also used to determine both direction and location. A simple example of determining direction is to accept the fact that the sun rises in the east and sets in the west. This means that if you look towards the sun at noon, you will be facing south. 

Most of the early property grants and communities in Nova Scotia were positioned by the use of the compass but astronomic observations using Polaris (the north star) or the sun to obtain direction were also common for surveyors. Just think of communities that have a North, South, East or West Street. These streets were either positioned to run in the directions in which the streets were named or, in the case of North Street and South Street in Halifax, they marked the most northerly and southerly limits of the community in the early days of settlement. 

The latest technology also has us looking towards the heavens but using man made satellites. The arrangement of satellites that we use to obtain position and direction is known as a "global positioning system", or better known by the initials GPS. For a few hundred dollars anyone can buy a small hand held receiver that will generally provide better than 30 meter accuracy. The survey community uses GPS but requires results to centimetre accuracy for various projects. The equipment required to obtain this high level of accuracy generally increases in price as the speed and precision of results increases. Costs can approach $100,000 for equipment that will provide centimetre accuracy results within seconds.

GPS is now being used for all facets of the military, transportation industry, recreational boating, forestry, camping and the uses are increasing, it seems, daily  The next step is that cell phones will also act as GPS receivers. You will always know where you are if you have your phone on. The potential down side of this development is that the phone company will also know where you and your phone are. So much for privacy.

Surveyors, however, are very excited about GPS since it can provide reliable results, all weather operation, 24 hour availability, direction between non-visible points on the ground, increased speed of location and total computer compatibility. The surveyor can now locate that old wooden post a mile back in the woods and relate it to the one at the side of the road. A line can then be marked on the ground from the road directly to the old post. 

You can learn more about GPS by searching the Internet. The results, however, will likely number several million ... more than enough information for anyone to become an expert.


Fred Hutchinson has been the Executive Director
of the Association of Nova Scotia Land
Surveyors since 1999 and is also a Past President of
the Association. Mr. Hutchinson was licensed in 1971,
employed by municipal government for nearly six years and
spent over twenty-two years in private practice.