Relocate the course using GPS from a Smartphone?

[gsm_peter]

It is easy to save a single place using a pin in Goggle maps (for example a parked car).

The accuracy can be type 1 foot.

 

Assume one store 2 pins for example Boie 1 and 6.

All courses are identical the same so the coordinates could then be easy calculated relative to boie 1 and 6.

 

Is there any easy way (app, tool) to import the total course positions and just relate/connect them to boie 1 and 6?

One can then navigate to all boies from the boat.

For us it would be much easier find the sunken boies next time.

 

Maybe there already is a solution for this but I have not found anything?

 

Any suggestions, ideas?

 

[BraceMaker]

Rope with marked distance? You could do the fixed anchor beneath a portable course.

 

I've also seen people build large floating PVC "squares" and swim them around to lay out courses. Sort of a pain.

[BCM]

My organization runs several hundred GPS units for mapping, data location, and point to point navigation. The biggest issue is accuracy. I am currently sitting in my home office and when I look at my 'Blue Dot' on Google Maps it shows me in the garage, about 20 feet away.

 

I believe the GPS accuracy of your phone will be at best +/-10 meters, if you get a recreation grade GPS to tie via bluetooth to your phone it will be about 2-3 meters. I use a 'Bad Elf GPS Pro' for work, tied to phone via BlueTooth which gives me about 2.5 meter accuracy, the GPS unit runs about $250. A Trimble R1 will get you 50cm accuracy but will run you about $2100.

 

I use a ESRI ArcGIS product to synthesis spatial data and export a map to AVENZA PDF maps with pins, it is pretty darn simple, but the ESRI software is not cheap (starts at about $500, though a consultant could likely whip up the shapefile and maps for a small price). AVENZA is cheap/free and works great. In my experience the GPS accuracy is the biggest concern.

[andjules]

Cell phone manufacturers have been talking about dual-frequency GPS chips for a while (2018) but while I haven't kept up on the details, broadly, the results haven't seemed to live up to the hype. 2nd gen dual-frequency chips getting into phones later this year. Google's Pixel 4 might be the best of the current bunch, but the hope is to get from old cell phone accuracy of +/-10 meters (~33') down to +/- 10-30 centimeters (4-12").

[gsm_peter]

Thanks guys.

I have not give up yet.

 

Found our course on satellite photo (Is it really cool)

Kartor.eniro.se Lambarö in Stockholm.

Link

Left Pregate: 6582647, 660307

 

I stored all boie positions in xls and my buddy will put into a Goggle Earth file for us.

 

Tested my Samsung S10 in my garden today and I get about 4-8 feet accuracy assume the Google maps streets are correct.

This is 7 miles from the course and I hope it will be similar there.

It is not to bad when you have to dive for the boies.

 

Will try to borrow a better GPS.

 

 

[Jtim3032]

@gsm_peter This is not a cheap solution (or at least not as cheap as you are hoping for) but since it uses RTK GPS, it is accurate to the cm. It also gives you lots more besides to help your driving improve. http://sure-path.com/for-homologators.html

[BraceMaker]

Part of what you might find is that even if the accuracy is 4-8 feet does it refresh fast enough so that when it says you're close that it wasn't a few feet back?

 

Be interesting if you could make an app which would beep progressively louder faster as you approached the approximate location.

 

I think it would be hard to watch a screen for a coordinate shift but if had a beeper you could just kayak around with a bag of balls and a phone in a waterproof case.