Iridium SBD

Iridium Short Burst Data (SBD) is a satellite messaging service on the Iridium low-Earth-orbit constellation that relays small data packets, and it is the standard telemetry path for modern ocean platforms. Argo floats, surface drifters, gliders, and moored buoys use SBD to send compressed profiles and receive command messages during their brief surface windows. Because Iridium covers the poles, two-way at higher data rate than the older Argos system, it cut the float surface interval from hours to about 15 minutes, which reduces drift error in the recorded position and lengthens battery life. SBD message payloads run up to roughly 340 bytes mobile-originated.