Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 09-06-2010, 17:05   #1
Moderator Emeritus
 
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 10,152
Chart Overlay Google Earth Question

Is there a way to show a vessels position including heading, COG and velocity vector, overlayed onto a Google Earth image? I would only have a cellular internet connection and at times no internet connection depending on the location. I am figuring I would need to download the images ahead of time.

Does Google Earth have pretty accurate WGS84 positions?

The reason I ask is sometimes I need to go into the small inlets into relatively shallow salt marshes and the NOAA charts are just not accurate enough or detailed enough for myself or the scientists.

If this can be done, how could I do this on a PC with Windows XP?
__________________

__________________
David

Life begins where land ends.
David M is offline   Reply With Quote
Old 09-06-2010, 17:56   #2
Registered User

Join Date: Mar 2008
Boat: Little Harbor Whisperjet 40
Posts: 334
Photo nav is way cool for places that don't have charts.
The Chatham, South beach, Monomoy area south of Cape Cod MA is a great example.

Ive done it but using images on a Navionics chart chip and Maptech discs.
To be sure of the data I took waypoints with a handheld GPS in the dinghy then entered them into the Raymarine on the boat. A twist of the sat overlay knob and for the most part it was an exact fit.

Active Captain may be getting there too.

Google Earth takes a big pipe to load and the imagery isn't any more up to date than what you can get on a disc. Just get a USB GPS and your set to go. Have fun!
__________________

__________________
Highlander40 is offline   Reply With Quote
Old 09-06-2010, 18:15   #3
Registered User
 
Viking Sailor's Avatar

Join Date: Nov 2006
Location: San Francisco Bay
Boat: Fantasia 35 - s/v Feeling Good
Posts: 1,074
Dave,

Not an overlay -- but how about something like this?

Paul
Attached Thumbnails
Click image for larger version

Name:	Cabo San Lucas.GIF
Views:	190
Size:	242.7 KB
ID:	16866  
__________________
Viking Sailor is online now   Reply With Quote
Old 09-06-2010, 19:03   #4
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,055
David, I wouldn't count Google Earth as being more suitable than NOAA charts for navigating inlets. Google's imagery is not live, it is often 2-3 years old and marshes and inlets will have shifted in that time.

Can you do it? Sure, a simple matter of programming, if you find someone who can do a Google Earth "mash-up". Would it be worth doing? I really would advise against it. Better to look over the side and use a depth sounder or local knowledge.
__________________
hellosailor is offline   Reply With Quote
Old 09-06-2010, 19:11   #5
Marine Service Provider
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,618
David, There is a product called EarthNC which can be used as a charting software with their GPS software.
www.earthnc.com
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 10-06-2010, 19:18   #6
Moderator Emeritus
 
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 10,152
Hello,
Thanks...I am not too concerned about scraping bottom at very slow speeds. I do it all the time in the shallows with this boat. The props are above the bottom of a full length keel.

Waterway,
Thanks for that link. That seems to be what I am looking for.

Paul,
Can OpenCpn put a boat icon over a Google Earth image?
__________________
David

Life begins where land ends.
David M is offline   Reply With Quote
Old 10-06-2010, 19:58   #7
Moderator Emeritus
 
hummingway's Avatar

Cruisers Forum Supporter

Join Date: Jan 2010
Location: Gabriola Island & Victoria, British Columbia
Boat: Cooper 416 Honeysuckle
Posts: 6,933
Images: 5
I'm writing an application at the moment that uses gps and google. You read the GPS location from the serial feed and send a request to Google for a map. I'm using the static maps api since it doesn't require a registration. You can request a marker at the gps location. There is a limit on how many requests you can make in a day.

When I download the map there is a centre point (i.e. the gps location) and a scale factor. I don't know if you could download a tile based on four corner points or not. If you could it would be just math to plot where the boat was on the downloaded map. The map can also be a sat image by the way.

I'll have a look at googles documentation and see what it says.
__________________
“We are the universe contemplating itself” - Carl Sagan

hummingway is offline   Reply With Quote
Old 11-06-2010, 05:44   #8
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Just be careful, David. I've been plotting my hiking expeditions on Google Earth, and here on Nevis GE is about 90' out of whack.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 11-06-2010, 06:38   #9
Registered User

Join Date: Mar 2008
Boat: Little Harbor Whisperjet 40
Posts: 334
Don't let the "instant" feeling of Google Earth fool you.
A few of the photos are 2 or 3 years old. Most are 5 or 6 or more years old. The date of the photos are displayed in the lower left hand corner.
You can also use the historical view button to see how the shoreline has changed.

Existing software and Maptech chart / photo discs will do the trick. A USB- GPS device is around 100 bucks. Use any laptop.
Of course you have to pay for the discs.

Most software will also leave a trail for later use.
__________________
Highlander40 is offline   Reply With Quote
Old 11-06-2010, 09:37   #10
Moderator Emeritus
 
hummingway's Avatar

Cruisers Forum Supporter

Join Date: Jan 2010
Location: Gabriola Island & Victoria, British Columbia
Boat: Cooper 416 Honeysuckle
Posts: 6,933
Images: 5
In looking through the documentation they don't expose the lat/long overlay in any way for static maps. Google earth is a js api that exposes their plugin so is a very different beast. It maybe with a commercial license you get something different but it looks like they are oriented to websites - their licensing only refers to websites, internal or external. The url format is pretty simple for the static maps but as mentioned you never know when the photo was taken. Lat/long in the url needs to be in decimal format. GPS gives it in what looks like decimal format but isn't so there is a conversion that has to take place.

http://maps.google.com/maps/api/stat...e&sensor=false
__________________
“We are the universe contemplating itself” - Carl Sagan

hummingway is offline   Reply With Quote
Old 13-06-2010, 12:39   #11
Registered User

Join Date: Jun 2010
Boat: Waterline 53
Posts: 4
Maptech Navigation Photos (*.sph) File Format

Hi,

Does anyone know about Maptech's Navigation Photos (*.sph) file format? I want to convert my Google *.jpg to *.sph.

I can then overlay the photos on top of my existing charts using Nobletec, Coastal Explorer, Chart Navigator, ....

I can already convert them to BSB Charts (*.kap) but navigation photo overlay is much better way of displaying the information.

Thanks.
__________________
Bill Stockton is offline   Reply With Quote
Old 13-06-2010, 17:54   #12
Registered User

Join Date: Mar 2008
Boat: Little Harbor Whisperjet 40
Posts: 334
Bill,
What you are really saying is that you want to avoid paying maptech for the photos that can be gotten free from Google? Cause the photos all come from the same place.
__________________
Highlander40 is offline   Reply With Quote
Old 13-06-2010, 18:13   #13
Registered User
 
Viking Sailor's Avatar

Join Date: Nov 2006
Location: San Francisco Bay
Boat: Fantasia 35 - s/v Feeling Good
Posts: 1,074
Dave,

It has been awhile since I looked into running GE and OpenCPN together as shown. I do remember that GE either can display a GPS location directly or via add-on software. You will also need software that allows two programs to have access to the same GPS data so that GE and OpenCPN can be run in parallel. I hope to get back on this project this fall assuming that the retro-fit goes as planned.

Paul
__________________
Viking Sailor is online now   Reply With Quote
Old 13-06-2010, 18:16   #14
Moderator Emeritus
 
hummingway's Avatar

Cruisers Forum Supporter

Join Date: Jan 2010
Location: Gabriola Island & Victoria, British Columbia
Boat: Cooper 416 Honeysuckle
Posts: 6,933
Images: 5
Quote:
Originally Posted by Viking Sailor View Post
Dave,

It has been awhile since I looked into running GE and OpenCPN together as shown. I do remember that GE either can display a GPS location directly or via add-on software. You will also need software that allows two programs to have access to the same GPS data so that GE and OpenCPN can be run in parallel. I hope to get back on this project this fall assuming that the retro-fit goes as planned.

Paul
Yes, you actually needs a driver that duplexes the serial stream. I would expect a performance hit from such a thing.
__________________
“We are the universe contemplating itself” - Carl Sagan

hummingway is offline   Reply With Quote
Old 13-06-2010, 18:32   #15
Registered User
 
Viking Sailor's Avatar

Join Date: Nov 2006
Location: San Francisco Bay
Boat: Fantasia 35 - s/v Feeling Good
Posts: 1,074
Quote:
Originally Posted by hummingway View Post
Yes, you actually needs a driver that duplexes the serial stream. I would expect a performance hit from such a thing.
Why would there be a performance hit? Both Windows and Linux are multi-tasking operating systems. That means the when the cpu isn't doing one thing it will do something else. And, as long as the cpu is not running at 100 percent utilization, there is time enough for all tasks to complete with time to spare.

__________________

__________________
Viking Sailor is online now   Reply With Quote
Reply

Tags
google earth

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Route Planning with Google Earth gauvins Navigation 10 07-01-2016 14:31
Google Earth ? phiggins Navigation 53 31-03-2012 21:39
Google Earth Sailing... Grasshopper Navigation 21 28-09-2009 12:02
Google Earth as an aid to navigation cat man do Navigation 9 01-05-2008 18:48
Google Earth is very interesting. Inthewind Off Topic Forum 1 20-04-2007 08:27



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:38.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.