Skip Navigation

Erratum for Demer and Conti, ICES J. Mar. Sci. 60 (3) 625-635.
ICES Journal of Marine Science: Journal du Conseil 2004 61(1):155-156; doi:10.1016/j.icesjms.2003.12.002
© 2004 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
This Article
Right arrow Extract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Demer, D. A
Right arrow Articles by Conti, S. G
Right arrow Search for Related Content
PubMed
Right arrow Articles by Demer, D. A
Right arrow Articles by Conti, S. G
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Validation of the stochastic distorted-wave Born approximation model with broad bandwidth total target strength measurements of Antarctic krill

David A Demer* and Stéphane G Conti

Southwest Fisheries Science Center 8604 La Jolla Shores Drive, La Jolla, CA 92037, USA

*Correspondence to D. A. Demer: tel: +1 858 546 5603; fax: +1 858 546 5608. e-mail: david.demer{at}noaa.gov.

In the computations of SDWBATTS(f) in Figure 4, the scattered vector was integrated over all orientations in the XY plane, where X is the main axis of the krill, but a factor of 2{pi} was erroneously substituted for the numerical integration which accounts for scattering at all angles in the YZ plane. Also, the krill in the study have since been measured to be appreciably fatter than the generic krill shape. In the revised computations and figure, the girth-to-length ratio was 40% larger than that of the generic krill shape, corresponding more accurately to the shapes of the krill in the study, and the scattered vector was integrated over all possible angles in both the XY and YZ planes. The revised Figure 4 is printed below:


Figure 1
View larger version (11K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 4 The average TTS of ten aggregations of Euphausia superba totaling 57–1169 animals. TTS data from 36 to 60 kHz had low SNRs (gray circles); those above 60 kHz are considered accurate to about 0.4 dB (black circles). The ±1 s.d. error bands (thin dashed lines) encompass the SDWBATTS predictions (solid gray), computed with g = 1.0357, h = 1.0279, s with a 40% larger girth-to-length ratio than that of the generic krill shape (consistent with measurements of the krill in this study), and the overall krill length distribution (see Figure 3). The SDWBATTS computed with the generic s (all other parameters are the same) is also plotted for comparison (thick dashed gray line). Because the random-phase term caused variations in SDWBATTS of less than 0.1 dB, expected values of TTS were effectively computed at each f using only a single random realization of phase. Error bounds on the prognosticator are thus negligible.

 
In Figure 6, the curves were calculated with a generic krill shape that was inappropriately thin, and the SDWBATS were too large by a factor of 4{pi}. In the revised computations and figure, the girth-to-length ratio was 40% larger than that of the generic krill shape, and the 4{pi} error was corrected. The revised Figure 6 is printed below:


Figure 2
View larger version (11K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 6 SDWBATS versus frequency (top panel), and krill length (middle) for four commonly used echosounder frequencies. The TS(f) spectra (top) and difference in TS at two or more frequencies (bottom) provide information for acoustically identifying Antarctic krill.

 

Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?



This Article
Right arrow Extract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Demer, D. A
Right arrow Articles by Conti, S. G
Right arrow Search for Related Content
PubMed
Right arrow Articles by Demer, D. A
Right arrow Articles by Conti, S. G
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?