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Old 23-06-2018, 08:17   #1
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GE2KAP Eye Height

Other than "employ trial and error", does anyone have any hints about optimum eye height for GE2KAP?

Are folks making large scale and small scale charts like a set of raster charts, or just a bunch of large scale ones?

Any hints which would save me a lot of trial and error will be gratefully received -- we will be leaving soon and I don't have a lot of time.
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Old 23-06-2018, 10:36   #2
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Re: GE2KAP Eye Height

I know, I am not answering your question, but....


What are you trying to achieve? GE-Satellite pics stored permanently and then displayed on opencpn?


If so, maybe try SASPlanet. It stores GE/Bing satellite pics and you can connect your GPS to it, it will show your position on the sat pic. Anything you looked at is stored locally for usage later. Or you select areas and let it download the tiles of various zoom levels (I find Z11 to Z17 sufficient). This by itself works well for the not-so-well charted areas.



It can also export these tile-sets as mbtiles, which the upcoming OpenCPN 5.0 can use (I run a 4.99 beta version).



Nothing wrong with GE2KAP, but I find the way SASPlanet -> mbtiles -> OpenCPN easier. It also gives me the option of loading BING sat pics, which i.e in the Bahamas are superior to GE.


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Old 23-06-2018, 11:22   #3
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Re: GE2KAP Eye Height

Quote:
Originally Posted by LeaseOnLife View Post
I know, I am not answering your question, but....


What are you trying to achieve? GE-Satellite pics stored permanently and then displayed on opencpn?


If so, maybe try SASPlanet. It stores GE/Bing satellite pics and you can connect your GPS to it, it will show your position on the sat pic. Anything you looked at is stored locally for usage later. Or you select areas and let it download the tiles of various zoom levels (I find Z11 to Z17 sufficient). This by itself works well for the not-so-well charted areas.



It can also export these tile-sets as mbtiles, which the upcoming OpenCPN 5.0 can use (I run a 4.99 beta version).



Nothing wrong with GE2KAP, but I find the way SASPlanet -> mbtiles -> OpenCPN easier. It also gives me the option of loading BING sat pics, which i.e in the Bahamas are superior to GE.


Dirk

Yes, I want GE images on OpenCPN for help in navigating poorly charted and uncharted areas of the East Coast of Greenland.

I am not familiar with SASPlanet but I'll have a look.

Thanks.
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Old 23-06-2018, 11:51   #4
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Re: GE2KAP Eye Height

Dockhead..
I use to make several images when close zoom is needed for large areas. There's a method to let GE2KAP follow a OCPN route and make sized images following that route. It's described in the GE2KAP manual.
For Greenland you may also check the Danish oeSENC charts (o-charts.org) and see what's covered. Planned for release July 1st, if you have the time. See: Swedish oeSENC charts to come - with our help.

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Old 24-06-2018, 07:26   #5
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Re: GE2KAP Eye Height

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Originally Posted by Dockhead View Post
Other than "employ trial and error", does anyone have any hints about optimum eye height for GE2KAP?

Are folks making large scale and small scale charts like a set of raster charts, or just a bunch of large scale ones?

Any hints which would save me a lot of trial and error will be gratefully received -- we will be leaving soon and I don't have a lot of time.
After making several thousand KAP charts using GE2KAP my experience is to use SAS Planet as the source for satellite imagery. The options of Google Earth, Bing, and ESRI/ArcGIS with SAS Planet help finding the clearest imagery. In some rare occasions all of them suffer from cloud cover but it isn't a perfect world. As for the 'eye height', in SAS Planet that correlates to the zoom level. I find that zoom level of 17 to be good for displaying shoals and reefs and often 18 (which not all of the sources provide). Once GE2KAP has calculated the number of charts it will produce for a route or polygon (these having been created in OpenCPN and saved) you can switch between sources to find the best imagery prior to creating the chart(s). My briefing charts on GE2KAP may help you which you can download here.

A companion piece on GE2KAP and SAS Planet can be downloaded from here.

Another source in SAS Planet is Navionics, both marine and sonar charts. Unfortunately, in my part of the world (SE Asia) the position errors can be dangerous. When I brought instances to the attention of the Navionics cartographers their reply was "Sorry for the inconvenience". These errors are predominant when away from shipping lanes ... where we cruisers like to roam. OK, my rant is over.

HTH, Terry
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Old 24-06-2018, 07:34   #6
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Re: GE2KAP Eye Height

Dockhead You might want to join the 'Google Earth to BSB/Kap' forum here.


Terry
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Old 24-06-2018, 07:37   #7
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Re: GE2KAP Eye Height

Quote:
Originally Posted by LeaseOnLife View Post
Nothing wrong with GE2KAP, but I find the way SASPlanet -> mbtiles -> OpenCPN easier. It also gives me the option of loading BING sat pics, which i.e in the Bahamas are superior to GE.
Dirk

Dirk, do you have a procedure for doing this?


Thanks, Terry
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Old 24-06-2018, 08:42   #8
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Re: GE2KAP Eye Height

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Dirk, do you have a procedure for doing this?


Thanks, Terry

Hi Terry, nothing written, so here it goes by quickly doing it:


Most important: You need the latest OpenCPN code, compiled from github, for OpenCPN to support the mbtiles format. you can get a compiled version here, but I believe there have been fixes since:

MBTiles for OpenCPN



SASPlanet can download squares, polygones, paths, of satellite images, or other formats SASPlanet displays. To make it work reasonably well in opencpn, I download rectangular sections with zoomlevel 11-17. In SASPlanet, look under "Operations/Selection Manager". Once a download of the tiles has finished (it does up to 4 threads in parallel), I select "last selection" and go to tab "export". in the drop down menu "Export selection to format", select mbtiles. in "save to" select a directory and give it a filename like: Martinique-satellite-z11-z17.mbtiles. check the boxes for zoomlevels you downloaded, like z11-z17. For the other options, most of which I don't know much about, I use:
  • Overlay layer: no
  • Add visible layers: no
  • use tiles from lower zoom: no
  • use xyz scheme: no
  • make tilemill compatible structure: no
  • image format: Auto
  • I haven't put anything in Name/Description/Attribution
Then hit Start, and a single mbtiles file is created with all the zoomlevels selected. Make opencpn aware of it (have the directory in the chart sources, rescan charts) and voila... opencpn can display it.


Phil with GE2KAP has done great work in making it all available as KAP files. But with OpenCPN supporting mbtiles, my use of GE2KAP has pretty much stopped. I think above workflow is simpler.


There may still be a few bugs in OpenCPN supporting mbtiles, ie, I think the Overzoom warning seems to come too early when zooming in. I think it needs more use by more people to iron them out.


Hopefully this gets you started


Dirk



Cheers


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Old 24-06-2018, 08:45   #9
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Re: GE2KAP Eye Height

You may also vote for a OpenCPN feature request, to directly read the chart cache of SASPlanet, that would eliminate the exporting step of above workflow...


https://opencpn.org/flyspray/index.p...s&task_id=1958
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Old 24-06-2018, 08:54   #10
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Re: GE2KAP Eye Height

Iím too lazy to build a database of images and master the software and I donít go to too many areas, which would justify the effort, so I just view the dodgy anchorages or reefs on GE, take a screen shot and keep a small selection of images until I need them. I use the images as a sort of proxy paper chart. If there is no additional useful info from GE compared to the charts then I donít save the image. You may find this approach works for your destinations too.
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Old 24-06-2018, 10:00   #11
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Re: GE2KAP Eye Height

Remember the venture farther plug in as well for anchorages nd smaller areas, just takes a few moments
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Old 19-07-2018, 15:13   #12
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Re: GE2KAP Eye Height

Does OpenCPN 4.8.4 support MBTiles?
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Old 19-07-2018, 15:31   #13
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Re: GE2KAP Eye Height

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Does OpenCPN 4.8.4 support MBTiles?

no, you have to compile from source, it will show as 4.9.9
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Old 19-07-2018, 15:32   #14
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Re: GE2KAP Eye Height

I sure hope it makes it into 5.0. cool as #%@$
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