2013: Acoustic target strength
measurement of banded grouper Epinephelus awoara (Temming & Schlegel, 1842) and threadsial filefish Stephanolepis cirrhifer (Temming & Schlegel, 1850) in the South China Sea.
The influence of ontogeny, physiology, and behaviour on the target strength of walleye pollock (Theragrachalcogramma).
Physiological factors causing natural variations in acoustic target strength of fish.
Modelling the target strength of Trachurus symmetricus murphyi based on high-resolution swimbladder morphometry using an MRI scanner.
Time varied gain (TVG) was 20 log R during echo integration and 40 log R during target strength data collection, where R = echo range (Johannesson and Mitson, 1983).
Acoustic reflectivity is determined by performing target strength (TS) analysis of echoes from single fish or by deriving a scaling factor from net samples, using the TS/size relation that is representative of the fish size in the subject school, according to:
where TS is target strength (in dB) and L is total length (cm).
When conditions were suitable, in situ target strength studies were conducted in order to collect target strength distribution information for a range of fish sizes and behavioral patterns.
Neither TS estimation technique has been able to take into account behavioral and other factors that influence fish target strength (Traynor et al.
2006b), and to validate models for target strength estimation (Demer and Conti, 2003).
As a first-order approximation, the theoretical predictions for the air bubble can be used to estimate the target strength of the fish by adjusting the radius of the rigid sphere to the size of the fish swimbladder.
The committee warns that recruitment continues to be a problem for the military, and neither the Army nor the RAF are likely to meet their target strengths