Figure 2.— Master station grid for groundfish survey sampling in northern Gulf of Mexico - West Delta area. Dot labeled 00-00 is start 



and end point for round-trip cruise track optimization. 



Since the grid used in the calculations was 

 square, a coefficient was included to account for 

 differences in absolute distance for one unit of 

 longitude vs. one unit of latitude. The coefficient 

 used for optimizing groundfish survey tracks is 

 52.10/59.85, which is the ratio of the distance in 

 nautical miles for 1° of longitude to that for 1° of 

 latitude at lat. 30°N. All longitudinal Cartesian 

 coordinate distances were multiplied by this 

 coefficient before calculations began. 



For the West Delta area, the cruise track was 

 optimized from a point located just east of the 



primary survey area (Pascagoula station number 

 00-00) through all randomly selected stations, re- 

 turning to the starting point. The optimization 

 program computed 11 solutions and the best route 

 in terms of the shortest distance was selected. 

 Output consisted of a listing of stations in proper 

 sampling order, and a plot of the stations and 

 optimum cruise track with every fifth station 

 labeled. 



The starting point of the cruise track was south 

 of Pascagoula for the East Delta area. Optimiza- 

 tion was done for a cruise track that visited all 



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