Post on 13-Jan-2016
description
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)
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