Page
107
of
133
Version 3.0 REV r000
Date 25-08-2010
Figure 92: Concept of Cylindrical Spreading
12.2.2
Absorption
Absorption is frequency dependent and refers to the conversion of acoustic energy to heat when it
strikes chemically distinct molecules in the water column. Magnesium Sulphate MgSO
4
predominates, with Boric Acid B(OH)
3
playing a major part at lower frequencies. Temperature is also
an influence on absorption. Absorption is one of the key factors in the attenuation of the acoustic
energy based on frequency; the higher the frequency, the greater the absorption. The higher the
sonar operating frequency, the more rapid the vibration (or excitement) of the particles in the water
and this leads to the greater transference of acoustic energy; thus, the attenuation of the acoustic
wave. This is the reason why lower frequencies are used to obtain deeper data. At 400 kHz, the
normal seawater absorption is approximately 100 dB/km, whereas at 200kHz the absorption is
approximately 50 dB/km. These are values for normal sea water (with a salinity of 35 ppt). Fresh
water has little, if any salinity (<0.5ppt), so absorption is considerably less.
Содержание 2022
Страница 1: ...SONIC 2024 2022 BROADBAND MULTIBEAM ECHOSOUNDERS Operation Manual V3 0 Part No 96000001 ...
Страница 2: ...Page 2 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 ...
Страница 28: ...Page 28 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 This page intentionally left blank ...
Страница 70: ...Page 70 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 This page intentionally left blank ...
Страница 72: ...Page 72 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 This page intentionally left blank ...
Страница 92: ...Figure 78 Smooth log information copied from real time survey log ...
Страница 96: ...Page 96 of 133 Version 3 0 Rev r000 Date 25 08 2010 This page intentionally left blank ...
Страница 112: ...Page 112 of 133 Version 3 0 Rev r000 Date 25 08 2010 This page intentionally left blank ...
Страница 116: ...Page 116 of 133 Version 3 0 Rev r000 Date 25 08 2010 This page intentionally left blank ...
Страница 124: ...Page 124 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 Figure 93 Sonic 2024 2022 Projector ...
Страница 125: ...Page 125 of 133 Version 3 0 REV r000 Date 25 08 2010 Figure 94 Sonic 2024 Receive Module ...
Страница 126: ...Page 126 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 Figure 95 Sonic 2022 Receive Module ...
Страница 127: ...Page 127 of 133 Version 3 0 REV r000 Date 25 08 2010 Figure 96 Sonic 2024 Mounting Bracket Drawing 1 ...
Страница 128: ...Page 128 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 Figure 97 Sonic 2024 Mounting Bracket Drawing 2 ...
Страница 129: ...Page 129 of 133 Version 3 0 REV r000 Date 25 08 2010 Figure 98 Sonic 2022 Mounting Bracket Drawing 1 ...
Страница 130: ...Page 130 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 Figure 99 Sonic 2022 Mounting Bracket Drawing 2 ...
Страница 131: ...Page 131 of 133 Version 3 0 REV r000 Date 25 08 2010 Figure 100 Sonic 2024 2022 Mounting Bracket Flange ...
Страница 132: ...Page 132 of 133 Version 3 0 Rev r000 Date 25 08 2010 Part No 96000001 Figure 101 SIM Box Drawing ...
Страница 133: ...Page 133 of 133 Version 3 0 REV r000 Date 25 08 2010 Figure 102 R2Sonic Deck lead minimum connector passage dimensions ...