Specifications

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5.17 Iridium satellite communication
Iridium is a satellite based cellular phone network. It is built upon a constellation of 66 low
earth orbit (LEO) satellites. The constellation is organized in such a way that every part of the
globe is covered 24 hrs a day. Iridium gets its name from the element Iridium (Ir), which has an
atomic number of 77. This name was chosen because the constellation would initially be built
upon 77 satellites. The Datawell Iridium option makes it possible to send spectral data and raw
displacement data directly over the internet to a computer running W@ves21. The Iridium
option consists of an Iridium satellite modem that fits in the electronics unit and an Iridium
antenna.
5.17.1 Antenna
The Iridium option uses a special antenna. The antenna is similar in design to the GPS position
antenna but it has a different colour. Whereas the GPS antenna is yellow, the Iridium antenna is
blue. The Iridium antenna is mounted in the option port labelled Iridium.When mounting the
antenna, always check if the rubber sealing ring is present and if the sealing ring contact
surfaces are clean. When testing the buoy on shore, make sure the antenna has a clear and
unobstructed view of the sky and avoid tall buildings and trees in the direct vicinity of the buoy.
As the Iridium satellites are in a low earth orbit (LEO) they are often seen by the buoy at
relatively small angles. Therefore, it is important that the buoy has a broad view of the sky
hence avoid tall buildings and trees.
5.17.2 Satellite modem
The Datawell Iridium option uses a 9522A Iridium L-band transceiver. This modem is built into
the electronics unit. To power the modem, a dedicated power supply is also integrated into the
electronics unit. See section 5.3.4 for the location of these components. The antenna connector
and the SIM-card bracket of the modem are accessible from the outside of the electronics unit.
5.17.3 SIM-card
Since the modem uses the Iridium network, an Iridium subscription is necessary. To identify the
Iridium subscriber on the network, a SIM-card is used (supplied by your local provider). The
Iridium modem is located on the iridium printed circuit board inside the electronics unit. Make
sure the electronics unit is switched off. To install the SIM-card, the hatch on top of the modem
must be removed by unscrewing the hex bolt. The following procedure must be followed to
insert the SIM-card correctly into the modem.
1. Remove the SIM-card cover by unscrewing the hex bolt.
2. The SIM-card bracket is located under the cover. Open the bracket by sliding it into
reverse direction of the arrow on top of the bracket.
3. When opened, insert the SIM-card carefully into the bracket. Please check the proper
orientation of the SIM-card, the cut-off corner should align with the SIM-card bracket.
4. Close the bracket by sliding it in the direction indicated by the arrow (lock).
5. Replace the SIM-card cover and fasten it using its original hex bolt.
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