surveying history

SURVEYING HISTORY

• Surveying dates back 5000 years

China

India

Babylon

Egypt

Egyptians

–Pyramids

–Roads

–Property and the Nile River

–Taxation

Ancient Techniques

• Ropes and Knots

• Water Levels

• Plumb Levels

Ancient Level

Greeks

• 250 BC Archimedes wrote the Sand Reckoner– Established the circumference of the Earth at 300,000

Stadia

– 1 Stadia = 1/10 of a mile

– 30,000 miles

– Actual circumference = 24,900 miles

Eratosthenes

SUN

A LEXA ND R IA

EA R TH

7 .2 °

9 0 °

THE WELL A T SCY ENE

ER ATO STHENES' CA LC ULA TIO N

7 .2 °

SUN

A LEXA ND R IA

EA R TH

7 .2 °

9 0 °

THE WELL A T SCY ENE

5 0 0 MILES

7 .2 °=

X MILES

3 6 0 °

ER ATO STHENES' CA LC ULA TIO N

X = 2 5 ,0 0 0 MILES

Greeks and Romans

• Surveyed for:– Aqueducts

– Roadways

– Military Camps

– Buildings

– Taxation

Fall of the Roman Empire

• The Dark Ages

• The Age of Enlightenment

• Navigation

• Up until the late 1700’s navigators struggled with the problem of longitude

Latitude

• Where you are north or south is relatively easy to calculate using a Sextant

Longitude

• But how do you calculate where you are East and West?

• Time is the key

• It takes 24 hours for the Earth to spin 360°

• 1 hours = 1/24 of a spin

• Or 360/24 = 15°

Longitude

• At the Equator 15° = 1000 miles

• 1° = 68 miles

• Problem: No reliable clocks existed that could be used at sea.

Longitude

• King George III of England offered a reward to anyone who could solve the problem of longitude.

• The reward was $15,000,000 to invent a clock that would loose no more than 3 seconds in 24 hours.

• The clock had to find longitude within 1/2°

Longitude

• 1Hr = 15°

• 1minute = .25°

• 2 minutes = .5°

• At the Equator that would be 34 miles

Longitude

• Many famous scientists tried to tackle the problem– Sir Isaac Newton– Galileo– Edmond Haley

• John Harrison – a British clockmaker– Invented the Chronometer

Colonial States Survey

• Colonial States Survey

• Public Land Survey System

What is Surveying?

• Locating Points on Land

• How do we locate points?– From Land– From Air– From Space

Types of Surveys

Plane Surveying

• Topographic Survey – Horizontal plane measurements over the surface of the earth, but including indication of changes in elevation.

Types of Surveys

• Property Survey – Sometimes called boundary or Cadastral survey. These are the most common and oldest type of plane surveying– Locating property lines– Usually required by law

• Route Survey – Surveys along highways, railroads, pipelines and power lines

Types of Surveys

• Hydrographic Survey are similar to Topographic but used for rivers, lake and other bodies of water.

• Construction Survey – – Used for the purpose of planning a construction

project.– Location and layout of buildings– Controlling the dimensions of a structure as it is being

built– As Built Survey Cover dimensional changes that

occurs during the construction project.

BREAK TIME

READING LEGAL DESCRIPTIONS

• Public Land Survey System (PLSS)

Public Land Surveying System

LET’S WRITE A LEGAL DESCRIPTION

NE ¼, NW ¼, Section 21, T2S,R2W P.M. Willamette

North American Datum (NAD)

National Geodetic Surveys

• Continuously Operating Reference Stations (CORS)

CORS BTON

• BTON