Humminbird Side Imaging Forums
General => General Discussion => Topic started by: Fish Pirate on January 19, 2012, 06:55:38 PM
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Hey Guys,
Pulling my hair out over this problem. When I enter a coordinate into humminbird pc it lets me enter 7 numbers. Say i enter
N 34 24.364 , W 086 19.461 and try to pull that up with the google earth app on humminbird pc it aint that spot it goes to.
Google earth coordinates have 8 didgets N 34 24 36.40 , W 08619 46.10. What is the difference and how do i solve this as i have downloaded 300 waypoints into my new 998c si's. i bought 2 and love them. thanks, humbled, Fish Pirate
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Hi Fish Pirate,
I would change the Google Earth options to use degrees and decimal minutes, so you can directly compare the coordinates with what you enter in Humminbird PC (if you enter degrees and decimal minutes there)
Latitude & Longitude is sometimes easier to specify in simple decimal degrees (DD):
30.123456 degrees North (Positive North, negative South)
120.123456 degrees East (Positive East, negative west)
Degrees Minutes and Seconds are all related to each other by a factor of 60, so to go from DMS to decimal degrees, you can use this formula:
DD = Degrees + (Minutes + Seconds/60.0) /60.0
From a quick Google search, here is a link to a simple online conversion tool you can use to experiment with conversion between DD and DMS:
http://transition.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html (http://transition.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html)
I hope this helps.
Tore
tore@sonartrx.com
http://www.sonartrx.com (http://www.sonartrx.com)
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Using decimal degrees will also allow you to be a bit more accurate as well.
Whatever measurement system you use; be sure that you are using the same one between HumminbirdPC and Google Earth so that it will be easier to understand and in case you are manually entering in waypoints. Don’t worry about converting from one measurement system to another as the programs and units can do that automatically and accurately.
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To go one step farther..
Mmake sure both system are using the same datum data base.
WGS84, NADS27, are mostly the usa standards. But there are many different bases.
If you dont use the same data base your converted position can be off by as much as 1000 meters...
Chuck
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I don’t think that you can change the Map Datum in Google Earth – or at least I have not found where to set it. I know that HumminbirdPC is set to work with the WGS84 map datum and it is not settable. Maybe Google Earth is the same way – anyone know?
Good point though: when working between programs or when manually entering in coordinates to/from a GPS unit: make sure the Map Datums used are the same.
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I dont think google lets you set datum only the display coordinates. I can recall this being a problem in a search a few years back.
The divers could not find the clearly scaned target. It was not until we went back out and found we were in a different place than the divers..
We had sonar nads27 and they were using google earth on a computer on the boat...
It does make a difference.
Another issue is if you have a decimal reading in 5 digit place and your unit you are going to put them in only uses a three digit decimal this will also make a location difference..Not too much if you are on the surface but for a diver in 0 viz it can be a concern...
Chuck
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Thans alot fellers! This is a great sight, helpful members and I an dern proud to be a charter member!!!