Para quem quiser mais nformações sobre o SPOT, aqui deixo um extracto do "<a href="http://www.sarglobal1.ca/00native/Guide_to_COSPAS-SARSAT.pdf">Guia do COSPAS-SARSAT</a>".<br><br>73,<br>António Vilela<br>CT1JHQ<br>
<br>"There may be some confusion between PLBs and SPOT devices since both use<br>satellites to signal for assistance. These two systems are completely unrelated<br>with nothing shared in common between the SPOT and SARSAT systems. They<br>
determine beacon locations by different methods. Notification of distresses travel<br>via different communicate routes to different organizations.<br>The SPOT device must acquire signals from GPS satellites in order to determine<br>
its own position. It then transmits this location to a communications satellite for<br>routing through a commercial communications network to the SPOT Response<br>Center in Houston, Texas. The Response Center must determine the<br>
appropriate SAR resources for the location and situation, and telephone that<br>organization.<br>This is in contrast to a PLB which does not need to know its own position and<br>only one of several available satellites needs to receive the signal in order for the<br>
position to be determined. Additionally notification of the distress is automatically<br>routed to the official SAR agency for Canada as opposed to a private company in<br>the U.S.<br><br>Advantages to the SPOT system include the fact that unlike a PLB, it can be<br>
used for lower-level calls for assistance, transmitting progress information, and<br>signaling that all is well. A PLB should only be used for severe emergency<br>situations only.<br><br>Shortcomings of the SPOT system include the requirement that the unit be able<br>
to have communications with multiple satellites (both GPS & communications)<br>which can introduce significant delays and unreliability. There are many reports<br>of messages from SPOT devices being significantly delayed, or not being<br>
received at all. Also since the system requires a paid subscription, after a few<br>years the total cost of operating a SPOT can exceed the cost of a PLB despite<br>the lower initial cost of the SPOT device itself. A PLB has a higher initial cost,<br>
but after purchase the only cost of owning a PLB is occasional battery<br>replacement."<br><br><br><br><div class="gmail_quote">2010/12/3 João Gonçalves Costa <span dir="ltr"><<a href="mailto:joao.a.costa@ctt.pt" target="_blank">joao.a.costa@ctt.pt</a>></span><br>
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<h1>SPOT - Localizador por Satélite</h1></div></blockquote></div>