299:
meter of the water column, with no additional motion due to the direct effect of the wind on the SLDMB's exposed areas. The USCG maintains several hundred SLDMBs for deployment and responds to more than 5,000 SAR cases each year. In the year 2006, more than 400 SLDMBs were deployed in SAR applications, with an average lifetime of 22 days. The USCG may release SLDMBs at their discretion to aid in search efforts. In remote areas, SLDMBs are deployed via C-130 aircraft or helicopters. The GPS unit on each SLDMB calculates its position every 30 minutes, and transmits the data via the ARGOS data collection system to USCG Operational
Support Center (OSC). During high traffic periods, the USCG may pre-deploy units in order to have existing data in areas where SAR operations are more likely, reducing the time required to collect ocean current data during the SAR process. SLDMB may be released as single units or as a group, depending on the situation required. In cases where the last known position is known and the time lag to SLDMB deployment are minimal, only a single unit may be necessary. However, if a sufficient time lag exists, or the last known position is not available, multiple SLDMBs should be used. An example of this second case would be a downed fishing vessel, in which only the approximate area of the vessel is known.
43:(GPS) sensor that, upon deployment in fresh- or saltwater, transmits its location periodically to the USCG to aid in SAR missions. Additionally, SLDMB are deployed in oceanographic research in order to study surface currents of the ocean. This design has also been utilized by Nomis Connectivity for secure ocean-based communications.
60:
according to USCG SAR guidelines. Upon reaching the ocean surface, the outer casing and parachute break away from the SLDMB, and the spring-loaded antenna deploys. Electronics consist of a GPS receiver, electronic transmitter and sufficient batteries to provide continuous data collection for a period of two weeks to one month.
298:
Because it has a small above-water surface and high underwater surface area, the effect of surface winds and waves has a negligible effect, instead moving with the flow of the upper 1m of the water column. The USCG has found that this instrument behaves as a 'zero-leeway' object, moving with the top
55:
SLDMB construction varies by manufacturer, but those used by the USCG consists of four orthogonal drag vanes 0.5m wide and 0.7m high of nylon fabric. These are supported by PVC arms at top and bottom, which extend from a cylindrical hull that contains the electronic equipment. Small floats are
59:
Deployment of the SLDMB may be accomplished by aircraft (both fixed-wing and rotary) or by ship. SLDMB deployed by aircraft are encased in a tube and attached to a parachute which decreases the impact produced upon hitting the water but without so much drag that the buoy can drift off-course
51:
The SLDMB is based on the Davis-style drifter design, which attempts to minimize the effects of wind and surface waves. This is accomplished by reducing the area above the ocean surface to small floats and an antenna. Below the surface is a series of drogue vanes to 70 cm. (less than the 1 m
52:
Davis-style buoy) in depth, which catch the ocean current, along with electronic equipment that deploys the vanes and antenna, receives the GPS signal and transmits the location to the USCG.
31:
designed to measure surface ocean currents. The design is based on those of the
Coastal Ocean Dynamics Experiment (CODE) and Davis-style oceanographic surface drifters –
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40:
32:
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attached to the end of each upper arm in order to maintain buoyancy, and a small antenna projects above the SLDMB.
36:
28:
367:[METOCEAN. (2008). METOCEAN SLDMB: Operating & Maintenance Manual (Version 3.0 ed.) Retrieved from
35:(NSF) funded experiments exploring ocean surface currents. The SLDMB was designed for deployment by
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which received the
Canadian Coast Guard Award in 2012 has the following dimensions and equipment:
393:
387:
217:
Top-loaded truncated monopole ARGOS antenna with active GPS element antenna above
39:(USCG) vessels in search and rescue (SAR) missions, and is equipped with a
308:
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133 mm (5.25 in) diameter X 216 mm ( 8.5 in) long
154:
500 mm (19.6 inches) X 650 mm (25.6 inches)
368:
16:
Drifting surface marker buoy which signals its position
8:
363:
361:
359:
357:
355:
279:Sensor Scientific Thermistor Model WM 103
287:Precision Resistive Divider on CC Board
320:
167:Float size (each is • of the cylinder)
345:
343:
341:
339:
337:
335:
333:
256:NAVMAN Jupiter 21 Model TU21-D450-031
7:
209:Four quarter cylinder foam floats
201:Heavy gauge marine grade aluminum
14:
262:
235:SLDMB Electronic Characteristics
231:
184:
75:
138:1400 mm (55.0 inches)
107:203.2 mm (8.0 inches)
99:1092 mm (43.0 inches)
162:400 mm (16.0 inches)
21:self-locating datum marker buoy
130:102 mm (4.0 inches)
1:
294:Search-and-rescue application
266:SLDMB Sensor Characteristics
146:1090 mm 43 inches)
115:11.3 kg ( 25.0 pounds)
41:Global Positioning Satellite
261:
230:
183:
74:
33:National Science Foundation
410:
178:8.0 kg (17.5 pounds)
143:Total cross section width
37:United States Coast Guard
276:Sea Surface Temperature
90:Buoy Prior to Deployment
369:http://www.metocean.com
248:METOCEAN Model MAT 906
159:Length of Exposed Mast
225:Flexible, Nylon cloth
121:Deployed Surface Unit
29:drifting surface buoy
267:
236:
189:
188:SLDMB Construction
80:
193:Buoy Construction
291:
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260:
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229:
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182:
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84:SLDMB Dimensions
79:SLDMB Dimensions
401:
378:
372:
365:
350:
347:
328:
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284:Battery Voltage
268:
237:
190:
96:Packaged Length
81:
409:
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384:
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366:
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70:METOCEAN iSLDMB
66:
49:
17:
12:
11:
5:
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351:
329:
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222:Drogue Panels
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175:Weight In Air
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156:
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148:
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132:
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127:Hull Diameter
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117:
116:
113:
109:
108:
105:
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100:
97:
93:
92:
86:
85:
65:
64:Specifications
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48:
45:
15:
13:
10:
9:
6:
4:
3:
2:
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253:GPS Receiver
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150:
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145:
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137:
135:Total height
134:
133:
129:
126:
125:
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118:
114:
111:
110:
106:
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102:
98:
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34:
30:
26:
22:
376:
323:
297:
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240:Electronics
232:
185:
151:Drogue Vane
120:
89:
76:
67:
58:
54:
50:
24:
20:
18:
315:References
245:ARGOS PTT
206:Flotation
104:Diameter
388:Category
309:GPS buoy
303:See also
271:Sensors
264:Table 4.
233:Table 3.
214:Antenna
186:Table 2.
77:Table 1.
394:Buoyage
112:Weight
27:) is a
47:Design
198:Hull
25:SLDMB
68:The
390::
354:^
332:^
19:A
371:.
349:.
327:.
23:(
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