Transcript Lesson 4 - Nautical Charts

Navigation
NAU 102
Lesson 4
Projection Comparisons
Other Projections
Stereographic/Orthographic
•Used for polar
navigation and
decoration
•Points projected from
opposite side of the earth
or from infinity
Plotting Sheets
•Used mid-ocean
•No land/ocean features
•Pre-labeled latitude
lines
•Unlabeled longitude
lines
•You can make your
own!
Plotting Sheets
Universal Plotting Sheet
•Can be used for any latitude/longitude
•You label the latitude lines
•You draw the longitude lines
•Longitude scale varies
by mid-latitude
Chart Scales
Scale – the ratio of a given distance on the
chart to the actual distance which it
represents on Earth.
e.g. 1:80,000 or 1/80,000
1 inch on chart = 80,000 inches on Earth
Chart Scales
Scale can be stated by:
•Ratio or fraction
e.g. 1:80,000 or 1/80,000
•A statement
e.g. “2 inches to the mile”
•A graphic scale
Chart Scales
Small Scale = Large Area
Large Scale = Small Area
e.g.
1/100,000 vs. 1/10,000
The larger the scale, the
greater the detail.
Chart Production
Charts are produced by the government
Charts of foreign waters:
•National Geospacial-Intelligence Agency
(NGA)
•Formerly National Imagery and Mapping
Agency (NIMA)
•Lots of other names, too!
Chart Production
Charts of US coastal and inland waters:
•National Ocean Service (NOS)
•Part of National Oceanography &
Atmospheric Administration (NOAA)
Chart Numbers
Charts are numbered with 1 to 5 digits.
•1 digit – no scale
(e.g. Chart No. 1)
•2 digits – 1:9,000,001 and smaller
•3 digits – 1:2,000,001 to 1:9,000,000
•4 digits – Special Purpose
(e.g. Plotting Sheets)
•5 digits – 1:2,000,000 and larger
Chart Numbers
2 & 3 Digit Charts
•Cover entire (or most of) ocean basins
•1st digit = Ocean Basin
Chart Numbers
Chart Numbers
5 Digit Charts
•Most common charts, day-to-day use.
•1st digit = Coastal Region
(Not the same as Ocean Basin)
•1st & 2nd digits = Subregion
•Digits 3-5 = Specific Location
(Counterclockwise within subregion)
Regions and Subregions
Chart Numbers
Chart Catalogs
•Produced by NGA and
NOS
•Free
•Lists all available charts
•Lists authorized sales
agents
•Several volumes, by
location
Use of the NGA Catalog
Example: You are planning to enter Rio de
Janeiro, Brazil.
• Step One: Review the index of the
world’s coastal regions/subregions.
Use of the NGA Catalog
Rio de Janeiro lies in Region 2
Use of the NGA Catalog
Step #2 Locate the
Small-scale Coastal Chart
Use of the NGA Catalog
Step #3 Locate the Harbor Charts
Chart Scales
Charts are classified by Scale
Sailing charts < 1:600,000
•Used for mid-ocean navigation
General charts 1:150,000 to 1:600,000
•Coastwise navigation
•Outside reefs and shoals
Chart Scales
Coastal charts 1:50,000 to 1:150,000
•Inshore coastal navigation
•Entering Large bays
Harbor charts >1:50,000
•Small harbors & anchorages
Chart Stock Numbers
For purchasing and inventory purposes.
E.g. 26AHA26230
•26 = subregion
•HA = chart series
•26A = portfolio number
•HA = harbor
•CO = coastal
•GN = general
•WO = world
•26230 = chart number
Chart Ordering
•Can purchase individual charts
•Can buy a portfolio
•All (or most) charts in a subregion
(E.g. 26A = General & Harbor charts for 26)
You must have the latest, large scale chart
for your location.
Chart Ordering
Print on demand
•Latest version is printed upon order and
shipped overnight
•http://www.oceangrafix.com
Authorized Chart Agent
•Copies on hand
•May need correcting prior to use
•http://www.naco.faa.gov/Agents.asp
Introduction to Navigation
Questions?