A high-frequency warm shallow water acoustic communications channel model and measurements

2007 ◽  
Vol 122 (5) ◽  
pp. 2580 ◽  
Author(s):  
Mandar Chitre
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Channel Model ◽  
Acoustic Communications

Multipath Effects on High-Frequency Coherent Acoustic Communications in Shallow Water

2013 ◽  
Vol 52 (7S) ◽  
pp. 07HG03 ◽  
Author(s):  
Su-Uk Son ◽  
Hyeonsu Kim ◽  
Jongmin Joo ◽  
Jee Woong Choi
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Acoustic Communications ◽  
Multipath Effects

Polychaete palaeoecology in an early Late Ordovician marine astrobleme of Sweden

2010 ◽  
Vol 148 (2) ◽  
pp. 269-287 ◽  
Author(s):  
MATS E. ERIKSSON ◽  
ÅSA M. FRISK
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Relative Frequency ◽  
Late Ordovician ◽  
Crater Floor ◽  
Drill Core ◽  
Upper Ordovician ◽  
Composition Characteristic ◽  
Post Impact ◽  
Early Late

AbstractThe post-impact Dalby Limestone (Kukruse; Upper Ordovician) of the Tvären crater, southeastern Sweden, has been analysed with regards to polychaetes, as represented by scolecodonts. A palaeoecological succession is observed in the Tvären-2 drill core sequence, as the vacant ecospace was successively filled by a range of benthonic, nektonic and planktonic organisms. Scolecodonts belong to the first non-planktonic groups to appear and constitute one of the most abundant fossil elements. The polychaete assemblage recorded has an overall composition characteristic of that of the Upper Ordovician of Baltoscandia. Oenonites, Vistulella, Mochtyella and the enigmatic ‘Xanioprion’ represent the most common genera, whereas Pteropelta, Protarabellites?, Atraktoprion and Xanioprion are considerably more rare. The assemblage differs from coeval ones particularly in its poorly represented ramphoprionid fauna and the relatively high frequency of ‘Xanioprion’. A taxonomic succession and changes in abundance and relative frequency of different taxa is observed from the deepest part of the crater and upwards towards more shallow water environments. The initial post-impact assemblage does not, however, necessarily represent a benthonic colonization of the crater floor. Instead it seems to be a taphocoenosis, as indicated by its taxonomic correspondence to the rim facies fauna recovered from Dalby Limestone erratics of the Ringsön island. The Tvären succession has yielded considerably richer scolecodont assemblages than hitherto recorded from the approximately coeval Lockne crater, possibly as a consequence of shallower water settings in the former area.

Measurements of high-frequency shallow-water acoustic phase fluctuations

2000 ◽  
Vol 25 (4) ◽  
pp. 507-515 ◽  
Author(s):  
S.J. Stanic ◽  
R.R. Goodman ◽  
R.W. Meredith ◽  
E. Kennedy
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Phase Fluctuations ◽  
Acoustic Phase
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