New Nuno News

by Simon Salter 27 November 2010 19:10

The Nuno Navigator team are ecstatically pleased to announce the release of Nuno 2.0. This marks the end of the beta trials. Many thanks to all the people that took part.

Nuno has come a long way since we started. This release includes many improvements:

  • Track Log. See where you have been, and save useful bits for later.
  • Anchoring Mode. See seabed features only when you need them. More.
  • Chart Overview. Makes moving around the chart easier, and shows you more information about the charts themselves. More.
  • Quick light recognition. Hover over a light on the chart and see a graphical display of its characteristics. More.
  • Data Import and Export. Save your tracks, routes and places as GPX data or KML (Google Maps). Load data from lots of sources into Nuno Navigator.

In addition there have been the usual bug fixes and lots of minor improvements which just make Nuno easier to use. image

Chart updating is better and faster. A single button click is all you need to keep your charts up to date. In fact you can even set this to automatic and Nuno will download updates whenever they are needed.

 

Nuno track monitorPosition input is better. Nuno will find your GPS automatically and display the ship position, course and speed. Improved filtering means that the display is more accurate and will not jump around.

 

 

You can quickly create a route plan, just a few clicks on the chart, and then follow it using the dedicated route monitor window. This tracks your vessel and displays course information, distances, cross track error and so on.

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Did I mention the search bar? It’s pretty good. You can type in a place name and Nuno will display a list of matches and partial matches. Click on one of these and the chart will fly you straight there. You can also type in a position as a lat/lon or even as a range/bearing from the ship.

 

 

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One of my favorites is the the pencil line. You can attach one end of this to the ship and it will move as the ship moves. Very handy for keeping an eye on the range and bearing to something.

 

 

 

 

 

Nuno is available at the absurdly cheap price of $100 for which you get and indefinite license to use Nuno and a one year subscription (worth $50) to chart updates, Nuno updates, support and other good things. More.

Bright flashing lights

by Simon Salter 21 November 2010 19:29

On a paper chart there is not really enough space to describe colors and flashing sequences of a navigational light so a code was invented. ‘F’ is a fixed light, ‘Fl’ is a flashing light (which means it is off more than it is on) and ‘Oc’ is an occulting light. Interestingly an occulting light does not lean towards the dark side. It is on more than it is off. In my dictionary ‘occulting’ also means supernatural, not capable of being understood by ordinary human beings and hidden. Here is the complete list of light types:

  • Oc Occulting
  • Iso Isophase
  • Fl Flashing
  • LFl Long Flashing
  • Q Quick flashing
  • IQ Interrupted Quick flashing
  • VQ Very Quick flashing
  • IVQ Interrupted Very Quick flashing
  • UQ Ultra Quick flashing
  • IUQ Interrupted Ultra Quick flashing
  • Mo Morse Code
  • FFl Fixed And Flashing
  • FLFl Fixed And Long Flashing
  • FOc Fixed And Occulting
  • Lit Unknown details

Which seems like quite a lot to me. Then there are codes for colors. ‘W’ is white. ‘G’ is green and so on. Finally there are indicators of period (time), height and range.

Here we have some raster and vector renderings of Point Hudson. imageimage

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The last one is from Nuno (we think it looks best). As you can see there is some confusion over height units but they are all basically agreed that we have a flashing red light with a period of 2.5 seconds. In Nuno we have also gone a step further and illustrated the flashing sequence with a diagram.

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This is a hover tip, a little floating window that appears when you hover the cursor in one position for a few seconds. We use a lot of these in Nuno.

For the most part reading the light characteristic is pretty straightforward but there are some rules about the characteristic string than can get a bit arcane. Such as: If a Characteristics field consists of Occulting and Flashing Light Characters that have a single period and are not Alternating and have no Grouping then these are merged into a single Light Character.

For example: Fl G Oc R 5s

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The use of Green and Red in combination is quite common despite the fact that red/green color blindness occurs in around 8% of males (women don’t often have this problem). With something like a traffic light it is possible to distinguish the type of light from its position but this is not so easy for marine navigation lights.

There are three types of range that get discussed with regards to lights:

The geographic range is all to do with geometry. It assumes perfect visibility and so is really to do with the curvature of the earth. Here is a typical range table:

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So from the bridge of a modest size vessel you should be able to see the Point Hudson light from over ten nautical miles away. Note however that the height is referenced to chart datum so in some circumstances the tide will affect visibility. In fact at low tide you will be able to see it from further away because it will effectively be higher above you.

Luminous range is to do with the power of the light and how well it penetrates the atmosphere. So assuming that the murk in the air is the the only thing blocking the light then this is a measure of how far away the light can be seen from. Obviously the brighter the light then the further away it can be seen. But what about color? Do some colors penetrate foggy conditions better than other? Anyone know?

The Nominal Range is what is written on the chart. Technically the nominal range is the luminous range when the meteorological visibility is 10 miles. Which of course begs the question as to what meteorological visibility is. Well one definition is that it is the greatest distance at which lights of 1,000 candelas can be seen and identified against an unlit background (does that help?).

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So if it is a bit murky, meteorological visibility down to 5 miles, then the Point Hudson light will only be visible from less than four miles away.