Comparative Test: Seaclear, OpenCPN, PolarView, Google Earth

[r.fairman]

Here is a link to a recent comparative test I conducted on a recent trip to Egypt and back. Please do not distribute outside of this forum as the final version has been submitted to UK and US sailing mags for publication. Feedback please.

https://docs.google.com/fileview?id=...uthkey=CP_g2Sw


regards

Richard Fairman JP BA Author SeaClear Unleashed 813,677 on the Amazon Best Seller List

[sredna]

Nie article

The URL for openCPN is opencpn.org, not opencpn.com.

OpenCPN does support S57 ENC charts, you could add that

Regarding position, I can say that openCPN places me precicely here in southern Denmark on any map, except one case where it is known to be a map problem.

[bdbcat]

Richard....

Nice article.

I wonder more about your positioning errors on cm93 charts.
Was the error universal (everywhere), or just on certain cells or regions?

Here in US, using WGS84, cm93 accuracy is generally equal to S57 ENC and NOAA BSB charts.

I have found that there are some very large scale cm93 cells that have a systematic error of a few hundred meters in the Bahamas, and elsewhere I presume. We have always said caveat emptor on cm93....

Thanks
Dave

[Rik-lu]

I used open cpn with cm93 for about 1500 miles in the baltic this summer.
always absolutely correct position. I could even see on which pier I was.

I have later exported my tracks to kml-files and can now watch them on google earth. There is easy to be seen that google earth is not at all correct on many places. According to google earth I sailed straight over some islands. :-)

by the way - thanks to Paul for the programm to export opencpn tracks to google earth ! see here:
http://www.cruisersforum.com/forums/...tml#post495159

http://www.cruisersforum.com/forums/...tml#post495182

[cagney]

r.fairman

From the summary for OpenCPN:

Documentation
Documentation is provided online but is limited (6/10)

Can you, please, expand on this a bit! What are you missing, etc.
This would be a great help as there is very little user feedback in this area.

Thomas

[r.fairman]

I think my comments about documentation should read " needs organising" Most people do not read any manual end to end, if at all. The easiest way to use a manual is to dip in when needed If the documentation had a Table of Contents and an index it would be easier to use. Or if it is converted to an html help file it would have an index generated and a search facility. A hirearchy of headings would help.

[sailias]

very nice article even though i disagree with some of the observations. May have an opportunity to test OpenCPN beyond home waters in Canada and coastal US as been invited to crew from Rio Dulce to Panama. Know nothing of this area and was wondering if there alternative map sources, which I dont mind paying for, to CM93 for the region to travelled. Comparative tests would be against my buddies CP180i plotter running CMAP wide charts. So basically looking for additional charts for the region.

Best regards and very nice article.

/ch

[r.fairman]

Thanks for the feedback. A test such as this will largely be subjective which has its limitations but may be more realistic in the real world than a lab objective test, I do not have any other sources of charts for the area of your trip but would be most interested in your comparisonwith a dedicated chartplotter.

My next article is using the same software with a netbook converted to a touchscreen and with a USB driven "at helm" touchscreen If I can make the remote monitor waterproof this may be the missing link in a truly viable PC based navigation system.

regards

Richard Fairman

[sailias]

would be very interested in the netbook touchscreen conversion method. One thing I noticed with my netbook was that a gps usb dongle cut the battery life in half. Have not tested a bluetooth dongle yet but suspect the the power curve will be less dramatic. Best of luck

/ch