Expedition Navigation Software » Save Tests using SOG as Boatspeed

Blizzard · 5/21/2018 12:26 pm

I have been out sailing a handful of times, and have saved a few dozen tests from the log files. However, I have had a difficult time calibrating Boatspeed properly on the B&G H2000 system. We have no heel angle sensor, and the instruments do not seem to respond when I tell them to decide which tack based on AWA.

In the meantime, my saved tests are useless with incorrect Boatspeed. Is there a way to save tests using SOG from the log file instead of Boatspeed?

I see there is an option to use SOG in EXP Calcs under instrument settings. If I check this box and re-save the tests, will this correct my data? Will checking this box correct future data until I sort out the calibration?

DuncanR · 5/21/2018 4:38 pm

Bliz
I am not quite clear what you are trying to do, I assume calibrate your speedo from tests i.e. look at recorded BSP versus recorded set and drift? Why is tack relevant to that exercise?
If you are trying to calibrate your speedo - and not having an inclinometer is a pain, but not a disaster - keep it simple, go out and motor up and down your favourite patch of tideless water. Does not have to be a mile, the B&G manual tells you how. But also create tests out of each leg and cross check back in the office in Excel.
And always do a visual check each day motoring out BSP-SOG in places of known current.

Blizzard · 5/21/2018 4:55 pm

Thanks Duncan,

The paddlewheel is just slightly offset from center, so we have very accurate Boatspeed on port tack, but it reads at least 10% high on starboard. I should have mentioned that earlier. The B&G manual describes how to calibrate an offset for one tack, using the apparent wind to decide which tack to offset. I am confident I can figure this out, but haven't had time to work on it. We are on Lake Michigan, so tide is virtually non-existent.

The problem I am trying to solve is how to correct previously collected data for polar editing. Expedition is new to the boat (and me) this year, and I have created a new polar from very limited data. I have realized that any tests collected for overlay on the polar chart are garbage, because the collected boatspeed is incorrect.

In order to get a basic idea of the accuracy of my polar chart, I'd like to save new tests using SOG instead of BSP. I will need to retro-actively analyze log files, and save tests using SOG. I was just curious if there is an Expedition function which changes the source of data in saving tests.

Your comment reminded me that perhaps I could create a second version of each log file in excel, copy/paste SOG into the BSP column, and then save new tests.

Last edited by Blizzard (5/21/2018 4:59 pm)

Nick · 5/21/2018 7:25 pm

Exp (Stripchart) saves SOG in the tests, but not instead of bsp.

Blizzard · 5/21/2018 7:37 pm

Nick wrote:
Exp (Stripchart) saves SOG in the tests, but not instead of bsp.

Thanks Nick. Is there a setting to view the test SOG in the polar editing window?

Nick · 5/21/2018 8:01 pm

There isn't sorry

Blizzard · 5/21/2018 8:13 pm

No worries. I'll make use of copy and paste.

Thanks!

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5/21/2018 12:26 pm #1

Save Tests using SOG as Boatspeed

5/21/2018 4:38 pm #2

Re: Save Tests using SOG as Boatspeed

5/21/2018 4:55 pm #3

Re: Save Tests using SOG as Boatspeed

5/21/2018 7:25 pm #4

Re: Save Tests using SOG as Boatspeed

5/21/2018 7:37 pm #5

Re: Save Tests using SOG as Boatspeed

Nick wrote:

5/21/2018 8:01 pm #6

Re: Save Tests using SOG as Boatspeed

5/21/2018 8:13 pm #7

Re: Save Tests using SOG as Boatspeed

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