Remote Site Imagery Using Iridium Short-Burst Data Service on Maker Buoy Hardware

Maker Buoy is an open-source hardware and software design for a low-cost ocean buoy. These devices can employ a variety of sensors and utilize the Iridium Short Burst Data (SBD) service for global communications. Approximately three hundred devices, based on the Maker Buoy design, have been deployed to provide in-situ geolocation and environmental data to researchers around the world. In addition to conventional “drifters” meant to follow and map ocean currents, versions of the Maker Buoy design are deployed on sailing vessels, autonomous boats, and at fixed terrestrial sites in remote locations. This paper describes the effort to integrate cameras into these devices to provide on-demand imagery where cellular communication is not available and cost, size, weight or power considerations do not allow for higher bandwidth satellite communications. Since the Iridium SBD service is limited to sending 340 Byte packets of data, the method of image transmission requires partitioning the raw JPEG images into 300 Byte packets which are indexed and reconstructed upon receipt at an endpoint designed for use with Maker Buoys. Users can set pre-set times for images, or send on-demand commands for imagery with options to control resolution, compression and other image parameters. This paper will describe lessons-learned from the camera integration process and SBD message reliability data when using multi-packet messages. Image quality relative to cost, time and energy required per image, and comparison to other satellite services is also addressed. Example applications are discussed including: monitoring biofouling on ocean drifters, ice accumulation on buoys in arctic environments, use onboard sail-equipped mini-boat operations, backup imagery for maritime infrastructure monitoring, and vegetation monitoring in remote Arctic environments. Future applications are discussed including using machine learning to classify images prior to transmission, and coupling of imagery with other onboard sensors.