Balancing Efficiency and Data Quality in Change-Aware Shipboard Sensor Data Transmission

Shipboard data servers sample many sensor channels at a fixed interval, although many channels repeat their value or vary only within a small tolerance. This study examines how far transmission to shore can be reduced while the received stream remains fit for its intended use. Traces from five liquefied natural gas (LNG) carriers with 1300–1870 channels per vessel were cleaned of no-signal sentinels and profiled by value type and temporal behaviour. Seven policies, from full and compressed transmission to change-only, heartbeat, deadband, spike-aware, and adaptive transmission, were applied and reconstructed at the receiver. Indicators derived from the International Organization for Standardization and International Electrotechnical Commission (ISO/IEC) standards 25012 and 25024 were evaluated against acceptance profiles for alarm monitoring, condition-monitoring dashboards, and aggregate evidence. Applied to all channels, the adaptive policy removed 82.8% of the records, with a normalised error of 0.08% on numeric channels and no missed state transition. Savings ranged from 73.9% on all float channels to 98.7% on quasi-static ones. Gzip reduced bytes by 85.9% but removed no records, and compressing the reduced stream removed a further 51–78% of the compressed bytes. Staleness, rather than reconstruction error, limited the reduction, so heartbeats must be set in elapsed time.