HiAOOS will develop, implement, and validate several ocean observing technologies to improve data collection in the ice-covered Arctic Ocean. A network of multipurpose moorings will be deployed for two years in the deep Nansen and Amundsen Basins. The network will provide point measurements of ocean and sea ice and active and passive acoustic data for several applications, including acoustic thermometry, geo-positioning of underwater floats, detection of marine mammals, geohazards and human generate noise. The mooring system will build on the successful basin wide Coordinated Arctic Acoustic Thermometry Experiment-CAATEX experiment and extend the existing Mooring Observations from the Atlantic Water Inflow Experiment (ATWAIN). A new generation of moorings will be developed where data can be transferred to the surface using ROV or winch technology. Ice buoys with new acoustic array technology will be developed for testing of underwater geo-positioning, local navigation networks for glider operations and for localization of geophysical events. These developments will advance several research infra structures with new observing technology and create new opportunities for forefront research. To unlock the capabilities of the new observing system methods and tools will be developed to analyse and visualize the observations for different applications using digital methods and technologies including machine learning. The methods and tools will be ingested into a digital platform blue Insight, and available through Zenodo. Training and use cases will use the platform to train different user groups associated with research infrastructures, research communities and technology developers. All data, methods and tools will be available following the FAIR principles. Field experiments will be carried out every summer from 2024 to 2026, and every field experiment will be assessed with respect to environemntal impact prior to the start of the experiment.