RV Investigator Voyage IN2025_V04 EK80 Echosounder

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2025_V04, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem - Voyage IV." The voyage took place between May 27, 2025 and June 28, 2025 (AEST), departing from Hobart and returning to Hobart.The Simrad EK80 split beam echosounders for 18, 38, 70 120, and 200 kHz were used to acquire acoustic backscatter data to a range of up to1500 m, between Hobart and Eden. Logging range was changed throughout the voyage based on depth. The 18, 38, 70 120, and 200 kHz frequencies were logged continuously for the extent of the voyage. The 333 kHz was set to passive for the duration of the voyage due to a known issue with the transducer.Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 1,164 files totalling 112 GB of raw data in this dataset.No processing has been conducted on this data.Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.