Ecdis Flashcards
What is ECDIS
Electronic chart display information system
It Is an aid to navigation which uses electronic navigational charts to display chart, passage and vessel information on a computer display
Requirements for ECDIS to be primary form of navigation
- type approved
- official up to date enc’s
- must be maintained to comply with latest IHO requirements
- risk assessment needs to be completed
- operators need to have generic and type approval.
- Form E
- must have approved, independent, up to date backup system
- onboard familiarisation training
What is a vector chart or enc
- Digital chart that is made up of different layers of digital information which can be displayed as a seamless chart
- Chart Information is contained in a database and can be displayed and removed as required.
- Developed with information supplied by approved hydrographic offices
- vector charts can be zoomed and will not pixelate.
What is a raster chart
- Rastor chart is a picture of a paper
- if zoomed in it will pixelate
- information can not be selected or deselected
- what you see is what you get
- very space consuming
What is a SENC
- A SENC is made up of information provided in the vector/enc chart so as to be displayed in the Brand/make of Ecdis system
- The SENC is specific to the make of Ecdis system.
Ecdis alarms
- crossing safety contour
- XTE/deviation from route
- Approaching a critical point
- Area special conditions
- Malfunction of Ecdis system
- Position system failure
- different geodetic system
Ecdis indications
- larger scale ENC available
- Information over scale
- No ENC available
- Default Safety contour
- route planning across SAFTEY contour
- Route planning across specified area (prohibited area)
- Crossing a danger in route monitoring
- different reference system (i.e. Ft or meter)
- System test failure
- Customised display
What is IHO S52
International standard for enc Presentation library for chart symbols, objects, colors
What is IHO S57
Sets the standard format for Data transfer between the IHO, hydrographic offices, manufactures, software developers and end users of ECIDS.
Types of display
Base display
Standard display
All layers
Custom
What is contained in the base display
Safety contour
Coast line
Isolated dangers that lie with in the safe area of the safety contour
Iso dangers that lie in safe zone like bridges or overhead cables or bouys
Traffic routing
Scale range, orientation, display mode
Units of depth
What is in standard/ default display
- all base info
- drying line
- AIDS to navigation (lights and bouys)
- boundaries of fairways and channels
- warning indications
- prohibited areas
- indication of cautionary notes
- visual and radar conspicuous features
- chart scale boundaries
What are the CATZOCS
Category zones of confidence
A1. +- 5m, extremely accurate, (6)
A2. +- 20m, Very accurate not as accurate as a1 (5)
All lower CATZOCS require additional safety margins
B. +-50mm, NAV Hazards not expected but may exist (4)
C. +- 500m low accuracy, depth anomalies may exist (3)
D. poor accuracy, severe depth anomalies may exist (2)
U. unsurveyed (1)
How to update ECDIS
Weekly update provide by the UKHO or a RENCS via a disk disk/USB or a direct download via Internet on to a separate computer and transferred to Ecdis system on a clean virus free sub drive
The weekly updates contain latest editions of charts and permanent corrections
Updates are made to the SENC and cannot be edited. The ECDIS system will log and record all updates that are made to the ENC.
How must NAVTEX and NAV warnings be entered into an ecdis
When NAV warnings are released via navtex or Inmarsat SAFTEY net they must be manually entered onto the chart sytem. They Ecdis system will indicate that they are manual corrections and may be deleted.