Representative tows (TOGA)

[andybeet]

TOGA values: A concatentation of the T, O, G and A codes assigned to an operation. Each standard survey tow is evaluated based on four categories, Type, Operational, Gear and Acquisition (T.O.G.A.). Type (T), Operational (O) and Gear (G) categories are used to validate each tow;

We have been using TOGA <= 1324 as a representative tow for years. This might be wrong!
2024 Fall survey data had a TOGA value = 1144 that was a bad tow.

Advice from survey:

"This is a failed tow for sure, hence the Gear-code of 4. I think using TOGA <= 1324 in your query is potentially returning failed tows. Instead, I would suggest that you use the individual TOGA codes for CRUISE6 > 200900. In other words, something like:
type_code < 2
operation_code < 4
gear_code < 3"

[andybeet]

@Laurels1 How are your sql statement structured to get representative tows only?

[Laurels1]

Yeah, I've been using the same code as in Survdat: TOGA <= 1324. Good to know. Thanks!

[Laurels1]

What is the variable name for A? And is it <5?

[andybeet]

I got this from Northeast Fisheries Science Center Bottom Trawl Survey Protocols for the NOAA Ship Henry B. Bigelow

Appendix F:
Excluding Tows from Stock Analysis:

• TYPE (T): Tows included in NEFSC Bottom Trawl Survey abundance estimates should be
  conducted following the protocols of the random and stratified statistical design. Standard
  NEFSC BTS tows are coded with a T value = 1. Station Type is coded values between 1 and 8;
  see section: T-TYPE of Station for details.
• OPERATIONAL (O): The operational category is coded values between 1 and 4. O Values= 1,
  2 or 3 are considered Representative; O Value= 4 is considered non-representative and should
  not be used in NEFSC BTS calculated abundance estimates. See section: O-OPERATIONAL
  Code for details.
• GEAR (G): The gear category is coded values 1, 2 or 4 (there is no G value=3). G Values= 1 or
  2 are considered Representative; G Value=4 is considered Non-Representative and should not be
  used in NEFSC BTS calculated abundance estimates. See section: G-GEAR Code for details.
• ACQUISITION (A): Acquisition category is coded values between 1 and 4. The A Value does
  not determine the validity of a tow. A Values= 1, 2, 3 and 4 are considered Representative.
  Tows coded with A Value=4 force an O Value=3 (O is coded with a value=4 if the operational
  parameters evaluate to that). See section: A-ACQUISITION Code for details.

[Laurels1]

Yup, looks like you don't need A for evaluating good tows. I have this in an older code:
type_code <= '1' and operation_code <= '3' and gear_code <= '2'
I think you do need the <= signs instead of < though or you will exclude good tows.

[andybeet]

looks like there are cases in svdbs.union_fscs_svsta where TOGA = null but for the same cruise6 in svdbs.tow_evaliation the TOGA codes are not present

Issue is becasue survdat pulls station data from svdbs.union_fscs_svsta. Because of this we will eliminate potentially respresentative tows.

eg.

select distinct TOGA
from svdbs.union_fscs_svsta
where CRUISE6 in 201003

returns a null

where

select distinct TYPE_CODE,OPERATION_CODE,GEAR_CODE,ACQUISITION_CODE
from svdbs.tow_evaluation
where CRUISE6 in 201003;

has no entry