Raster charts

castaway

castaway

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Is there anyone out there who uses these on their lap top? (or are they only available in Ethiopia?)

Having just got a cheapie machine I was thinking of hooking up to either my existing Garmin GPS or an independent unit.

As I have a wheelhouse with a big shelf affair infront of the wheel it would be fairly easy to adapt the top to accomodate the laptop and have instant display rather than using my present system which is a Yoeman(which I like) but is down in the chart area.

Many tks Nick
 
ARCS are raster. some people scan their charts and then use them in SeaClear.

Personally I prefer Vector charts.

The ability to see where you are on the screen is a great boost - Provided you remember it is only as accurate as the chart being displayed, and use some other means to recognise that you are in the correct part of the ocean e.g. echosounder, or an occasional clearing bearing etc.
 
Raster charts certainly have the virtue that they are direct replicas of official paper charts. Vector charts may be inaccurate, due to errors introduced in the vectorisation process. That said, a thread not long ago showed most peeps, including me, using vector charts alongside paper charts. If raster charts were available giving same scale cover as vector, I would go for them, but they aren't, or not at a comparable cost.

Scanning your own is contradictory, really, but scanning someone else's is a different ballgame. /forums/images/graemlins/wink.gif
 
Most offerings from Hydrographic Offices are Raster .... the offerings from third parties often Vector.

Raster - and before someone says it ... they are NOT all direct scans / copies of paper charts ... raster is the type of graphic and can actually be produced from other source .... (so I am informed by others more learned about the subject than I !!). Raster often have zoom problem in that as you zoom out - the info gets more difficult to read and text etc. is smaller and smaller ... As you zoom in - the graphic pixellates and breaks up ...

Vector will give zoom in and out with still readable text and data ... do not be fooled though as the zoom in capability does not give greater detail than original source ... just allows you to read it without pixellating ...

Raster has a fixed data display / info on screen ... additional as marks / points you add as overlays .... Vector has layers that you can turn on / off at your command ... still with ability to add marks / points etc. as overlays ...

It is widely accepted and also mentioned by various agencies etc. that eventually most chart offerings for electronic use will be Vector with Raster phasing out .... way of the world and evolution ...
 
Don't disagree with any of the foregoing - but comment that chartplotters are way behind even basic land GIS systems - our office GIS displays both vector and raster and can overlay them.

I use ARCS skipper raster charts - about £200 for 18 charts that cover my likely cruising area, using Dolphin Maritime's PC yacht chart display europe - excellent at £89 - on a home-built Shuttle. Hard copy HO leisure folios and a few Imrays as back-up, natch (old enough to have learned my coastal nav when only ships had GPS...). Got Seaclear as well, and an A3 scanner in the office..

Vector charts will win out in the end, of course.

There's a seller on eBay who's 'hacked' Tsunamis and is flogging all 6000 charts and the prog for about £15 - but no updates and HIGHLY ILLEGAL to own or run but a friend of a friend is considering having a version on the laptop as an emergency backup..
 
Why pay 15 quid ....

You can go on any P2P netwrok and download for free .... that's probably what he did ....

There's the complete CMap93, Maptech, Seapro .... they are all there .... but all illegal .....

Even Maxsea has finally been cracked .... after years of failure ...

ILLEGAL !!
 
Some old bollocks there, Nigel, and some good sense!!

First, television is raster, fax is raster, they are both scans of an image - and so are the raster charts, scans, no more no less.

Next, zooming. In a 'properly organised' raster charting environment, the software will switch charts (ie the original scanned documents) as you zoom in or out, so you are looking at the most appropriate chart for the area of your screen. It is the fact that so many charts are required that puts the cost up. Cheapskate raster versions using one chart inappropriately are what you are referring to. If you are using the right chart, you will not need to zoom in or out. If you do need to zoom(change scale) then the chart used should change.

But vector charts are the same!!! With CMAP for instance, you can right-click and get the orginal chart used for the data, and you will find the chart changing as you zoom. With Maxsea, it will identify the scale at which the current chart is properly to be viewed. I have never had occasion to switch off any layers with CMap, tho you're right, the facility exists.

But you are quite right in the long run; vector will win, but it requires the data to be made far more correct than it currently is - hence most peeps using paper charts as well, esp for large-scale apps. and Reeds helps with the little minicharts (c/w disclaimers) for close in pilotage.
 
Dolphin Maritime

Aha - A fellow user
Excellent programme
Excellent Charts
Linked to Garmin 76
Sits in Wheelhouse
Perfect solution.
Updates are not too expensive and we have around 200 charts which the ageing laptop seems to be able to cope with easily.
The dolphin programme is very easy to use - especially dropping waypoints in and creating routes so I do this through the programme rather than storing them in the GPS unit.
 
Dear oh dear .... the same old stuff comes up ...

Of course raster is scan ...

We are not talking about auto-load maps for zooming etc. - the point I made was that raster is based ona single zoom level for each of its charts ... vector is based on data layers and can zoom in / out with loss of image quality.

Whether you use Maxsea or CMapECS makes no difference as Maxsea uses the CmapECS engine to use Cmap93 charts.

Raster is designed to be viewed at one level - then switch to another chart for closer in or zoom out.

Please do not confuse by adding in what I haven't posted on ... your points are valid in themselves of course ...

Oh and on the point of accuracy .... It is swings and roundabouts there I'm afraid ... Most people on these forums cannot afford the luxury of full commercial package CMapECS ... I have visited many ships and had a gander at the charting packages they use ... we are behind when it comes to most I see ... and I for one am not going to pay the thousands that they cost ... Also for anyone who takes the Cat Ferryu from Tallinn to Helsinki .... you will be treated to a beautiful TV display of charting as you approach Helsinki ... in I believe Vector format ....
 
Yes, Ive just mentioned the Ebay charts/software to a friend who is considering them. I'll be interested to see how he gets on when they arrive...

Regds Nick
 
Re: Dear oh dear .... the same old stuff comes up ...

I can see my message missed the mark, and hit a tender spot instead. (Not sure what I attributed to you that you didnt say??)

Zooming ONE raster chart is like walking back from a chart on the wall, or taking your nose close up to it. Neither makes much sense. I would not do that to a paper chart, nor would you. It is meant for reading at one magnification. If that magnification does not reveal enough coastline, get out another smaller scale chart, or if you want more detail, then opposite. But you should not want to use different views of one paper/raster chart - that was the backing to my comment about duff raster-based systems.

We, or I, AM talking about auto-loading raster maps as one reveals more or less coastline. So too in CMap, a new dataset is accessed for the appropriate vector representation. There is no difference in principle, methinks.

I repeat that I, too, think the future is vector - eventually, we will have no paper charts at all (outside droggies office, that is) and our vector maps will receive their NM's on-line, just like all the other software we have - of course, it will cost...
 
Not tender spot ... just brought up info that was \"off target\"

We have both in our subsequent posts both hit on very similar statements ...

The silly thing is you say about cheaper raster systems ... wrong - in fact near all raster based charting systems DO zoom in / out on same chart for limited amount BEFORE calling up a different scale chart ... so unless you do it yourself in calling up scaled cahrts - the programs - Maptech, Seaclear, Maxsea, Seapro etc. etc. all act similar in that respect.

When you mention Vector charts their principle is different and datasets although referenced to a prime scale are available to all scales but do not suffer the pixellation that raster does BEFORE changing chart.

The argument or discussion nhere is going round in its normal circle and we both say similar - but attacking slightly doifferent angles / items within the matter ...

Vector will always be the better system pc wise.... raster when comparing to paper chart on table ... each has its merits ... each has its downside ...
 
Re: Ok... (nm) -- I was just warming to it then !!!

Cor ... back to boredom again ...

Cheers and no hard feelings ... cause I could of course be wrong ....
 
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