Iridium has 66 satellites in orbit around the Earth, allowing coverage anywhere on Earth 24 hours a day, 7 days a week. No other satellite network has truly global coverage. Messages sent via Iridium take just seconds to reach other systems, via e-mail or directly using the proper integration modules.
The idea of implement Iridium in Veronte system is to allow the operations BLOS (beyond line of sight), where the common data link (trough radio signal) is not fully operative. With Iridium, the data link is established trough the satellite network so the mission can be carried out even when there is not line of sight between the ground station (fitted Veronte Ground Autopilot) and the UAV (fitted with the AIR autopilot).
It could be considered that the Iridium module replaces the radio module installed within Veronte Autopilot, establishing then the communications (telemetry and telecommands) trough the Iridium satellites.
The module used for the integration with Veronte system is the RockBLOCK Mk2 provided by ROCK SEVEN.
The Iridium module communicates to the autopilot trough the serial port. Once the option “Iridium” is selected in the devices list of that port (see section 6.2.2), the menu shown in the previous figure is now visible in the “Sensors” list.
The different parameters to configure the Iridium module installed on the autopilot are presented as follows:
- RSSI (received signal strength indication): variable that indicates the strength of the signal received at the Iridium module (the one that comes from the satellite). It can have values from 0 to 5 (discrete), where 0 is a power at or under the sensitivity level, 5 corresponds to 10 dB or more, and the other values represent an increment of 2 dB over the previous number. The RSSI can be stored in a user variable to display the Iridium Link Quality on the workspace.
- Change Prefix: the commands sent to the Iridium module are started with a prefix. By default this prefix is AT, but it can be changed in Pipe. Press “Change Prefix” and a window will appear allowing the introduction of a new prefix.
- System: this window has the commands to interact with the Iridium module. The system has two buffers, being one for write data to the module (MO) and the other one to read from it (MT). The system (Pipe) writes the messages in the MO (mobile originated) buffer according to a certain pattern (message in binary code + 2 bytes checksum) and the module transmits that message to the linked unit through the satellites. On the other hand, when a message arrives at the Iridium module, it is stored in the MT (mobile transmitted) buffer until is read by the autopilot. In both cases, the buffers can only have one message. When interacting with the System commands the following window is used (it appears when clicking on the pencil icon that appears beside the command).
- The zone highlighted in red allows to configure Veronte Pipe variables according with the messages transmission (Data Sync variables) and the error linked to those variables (KBIT variables). The last panel allows the user to filter messages and to decide which ones will be send to the Iridium network.
Messages configuration window
In general, the messages configuration has to be done according to the used module.