Expedition Navigation Software 
1 of 1- DuncanR
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Offline - From: Up and down East Coast Aus
- Registered: 9/16/2015
- Posts: 465
Blank "Boat 5" lines in logfile
Something odd here that I haven't seen before. Below is the start of a pair of lines from a logfile. First row is as in every logfile, Boat id, UTC, BSP, AWA, AWS, TWA etc; I haven't pasted the whole line.
Then the second line "Boat 5", and the rest of the line blank.
This occurs maybe 700 times in a 800k row file.
Any guesses people?
Row 1: 0 43385.58 10.009 48.11 5.048 9.81 1.199 6.7543 385.58 etc etc
Row 2: 5 and then the rest blank
Last edited by DuncanR (10/15/2018 1:58 am)
- ZeeZee
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- Registered: 3/30/2016
- Posts: 321
Re: Blank "Boat 5" lines in logfile
Just guessing:
Maybe boat 5 is mapped as an AIS target? Then you receive just aan AIS 'ping' from that boat as it is in your vicinity, but not enough data to actually bring meaningful data into your log file (SOG, COG).
- Nick
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- Posts: 2,740
Re: Blank "Boat 5" lines in logfile
As ZeeZee says, it probably is an AIS target.
However, Exp will only write a line of data if there is at least one valid item in it so it won't be completely empty.
- DuncanR
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- From: Up and down East Coast Aus
- Registered: 9/16/2015
- Posts: 465
Re: Blank "Boat 5" lines in logfile
Gentlemen, well spotted. It is indeed AIS target #5, one row every 30 seconds, and COG and SOG are populated ..... pretty much as you would expect.
The the next question becomes - why weren't boats 2 - 4 present in the data at all, noting that many boats in this part of the world have AIS on only til they clear the harbour - but I don't expect this forum to deal with human behaviour issues!
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Thread Starter- Nick
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Re: Blank "Boat 5" lines in logfile
How do you like the Sydney forecasts Duncan?
- DuncanR
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- From: Up and down East Coast Aus
- Registered: 9/16/2015
- Posts: 465
Re: Blank "Boat 5" lines in logfile
Nick, I promise I will get to them, they are in my in-tray to process, but right now I'm writing a consulting report that has to pass "the weight test" ... another story entirely. Promise you will have the analysis.
Regards
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Thread Starter- DuncanR
- Expert
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- From: Up and down East Coast Aus
- Registered: 9/16/2015
- Posts: 465
Re: Blank "Boat 5" lines in logfile
Incidentally, I'm not dodging the issue .... no model got it quite right - in a transitioning system that will always be true - so anecdotal memories won't cut the mustard as a fair and systematic approach
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Thread Starter