2. Legal land descriptions are an important part of transfer of property, Taxes, and determination of acreages. Most states still only recognize plane surveys, by transit and rod, as A way to physically locate the legal boundaries. United States government agencies such as the BLM, Forest Service, And USDA are now using advanced GPS receivers to locate ground Points and establish boundaries. A review of legal descriptions and how to read and assign them is Very important. We will also work with a simple hand held GPS unit so you can See some of the capabilities of GPS.

3. Origin: Surveying is thought to have with the Egyptians and their Need to tax land. As the Nile river flooded each year each Year the boundaries had to be relocated. Types: Meets and boundaries: Is an only inaccurate system that Described the location of property By its proximity to physical features Of the land, such as trees, rocks, and Fences. This produces irregular shapes and It may be fairly difficult to determine The actual number of acres.

4. Types of descriptions cont. Rectangular: Established by the 1785 continental congress, Provided a way by which public lands would be Divided up to produce regular shapes and sizes Of parcels of land. This gave rise to the use of Township, Range, and Sections. It is also then associated with Latitude and Longitude. The use of specific north south lines designated as principle Meridians and specific east west lines called Base lines and their intersections called initial points Are used to locate specific areas. There are 35 regions for surveying purposes in the US each has their own initial point.

5. Standard parallels of latitude are spaced at intervals of 24 miles north And south of the base line. Each is designated by 1 st North or South. Guide meridians are spaced at intervals of 24 miles east and west of The principle meridian. Each designated 1 st east or west. Each of these 24 mile square Pieces of land is called a TRACT.

6. Each tract of land is then divided into 16 townships.

8. Each township is 6 miles square. It is then divided into 36 sections That are one mile square and have 640 acres in them. Remember how they are numbered. Section 16 is usually a school section.

9. Each section can be divided into smaller areas, usually in ¼’s or ½’s. Legal descriptions Begin with the Smallest unit of a Section, section, Tier, and Range.

10. GPS (Global Positioning System) The use of satellites to find an exact location. Made up of 24 satellites orbiting the earth in a specific orbit. Controlled by Department of Defense. Used by military, government, and civilian. Signals from 3 satellites are need for a 2 dimensional position (Lat, and Lon) Signals from 4 satellites are need for a 3 dimensional position (Lat, Lon, and Elevation) Errors in satellite signals may be caused by the atmosphere, Interference from other waves, reflection, and proximity of the Satellites being used (GDOP) TRIMBLE CD

11. Advanced mapping issues: Because the earth is neither flat or perfectly round, trying to project Points on its surface to a flat map is very difficult. GPS units use DATUMS, which are a mathematical equation of the Shape of the earth. Most use WGS-84 as a base. Flat mapping coordinate systems CTRS: converts measurements to Lat and Lon Plan coordinate system: uses equations to try to locate areas correctly On the map but looks distorted. UTM: The earth is broken down into zones along certain longitude Lines then the location north or south of the equator is given in Meters. Used by military and some government agencies.

12. GIS (geograpraphic information system) Uses information gathered by a GPS unit and projects them onto An electronic map. Many features can be added to the basic map such as roads, rivers, Population, land ownership, well location, weeds, etc. Custom made maps for agriculture, emergency response, and City planners. Most government agencies use ArcView