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, asA 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 groundPoints 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 canSee some of the capabilities of GPS.

Origin: Surveying is thought to have with the Egyptians and theirNeed to tax land. As the Nile river flooded each year eachYear the boundaries had to be relocated.

Types:

Meets and boundaries: Is an only inaccurate system that Described the location of propertyBy its proximity to physical featuresOf the land, such as trees, rocks, andFences.

This produces irregular shapes andIt may be fairly difficult to determineThe actual number of acres.

Types of descriptions cont.

Rectangular: Established by the 1785 continental congress, Provided a way by which public lands would beDivided up to produce regular shapes and sizesOf parcels of land.

This gave rise to the use of Township, Range, andSections.

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 pointsAre used to locate specific areas.

There are 35 regions for surveying purposes in theUS each has their own initial point.

Standard parallels of latitude are spaced at intervals of 24 miles northAnd south of the base line. Each is designated by 1st North or South.

Guide meridians are spaced at intervals of 24 miles east and west ofThe principle meridian. Each designated 1st east or west.

Each of these 24 mile squarePieces of land is called aTRACT.

Each tract of land is then divided into 16 townships.

Each township is 6 miles square. It is then divided into 36 sectionsThat are one mile square and have 640 acres in them.

Remember how they are numbered.

Section 16 is usually a school section.

Each section can be divided into smaller areas, usually in ¼’s or ½’s.

Legal descriptionsBegin with the Smallest unit of aSection, section, Tier, and Range.

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 theSatellites being used (GDOP)

TRIMBLE CD

Advanced mapping issues:

Because the earth is neither flat or perfectly round, trying to projectPoints 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 correctlyOn 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 inMeters. Used by military and some government agencies.

GIS (geograpraphic information system)

Uses information gathered by a GPS unit and projects them ontoAn 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