Inputting trawl survey location data

[annepolyakov]

Hello! I had a quick question about inputting trawl survey location data. Since trawl surveys are conducted along a transect, which location along the transect is typically used for input into the spatiotemporal model? For example, in the Pacific Cod example using the sdmTMB package, do the locations refer to the starting/ending/middle location along the trawl? Thank you!

[Lewis-Barnett-NOAA]

Yep, ideally the middle if you can calculate it accurately, or start/end.

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On Thu, Jul 18, 2024 at 10:04 AM annepolyakov ***@***.***> wrote: Hello! I had a quick question about inputting trawl survey location data. Since trawl surveys are conducted along a transect, which location along the transect is typically used for input into the spatiotemporal model? For example, in the Pacific Cod example using the sdmTMB package, do the locations refer to the starting/ending/middle location along the trawl? Thank you! — Reply to this email directly, view it on GitHub <#357>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKMJP4FSEXRO3TEDJM3EELZM7YQTAVCNFSM6AAAAABLDCOI72VHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZWHE2TAMZXGE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

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[seananderson]

Yes. And the custom is usually region-specific, I think. That Pacific Cod dataset is likely using the starting coordinates. One hopes that the estimated correlation range is large enough that this choice doesn't make too big of a difference.

[annepolyakov]

Thank you so much, that is really helpful!