## 4 New Technologies  
While the initial efforts of the Nippon Foundation GEBCO Seabed 2030 Project will focus on the identification and assembly of existing data sets, identifying key data gaps, and facilitating new data collection, it will also promote the development of new technologies that may increase the efficiency, accuracy, and resolution of seafloor mapping data. Seafloor mapping technology has been advancing at a rapid pace since the invention of the echosounder in the late 1920s. Over the past few years, multibeam sonars have steadily increased the number of beams that ensonify the seafloor and the density of their measurements (both along- and across-track), improved their ability to compensate for ship motion and invoked enhanced bottom detection techniques that have greatly improved the quality of the data being collected. In shallow water, when water clarity permits, bathymetric LIDAR (LIght Detection and Ranging) and satellite-derived bathymetry (bathymetry from satellite imagery as opposed to satellite altimetry-derived bathymetry which comes from the gravity field) have provided efficient ways to produce estimates of bathymetry in regions where multibeam sonar mapping is much less efficient. While incremental improvements are ongoing, the challenge of mapping the world ocean will benefit greatly from new technological breakthroughs, and thus the Seabed 2030 Project will explore, initially through workshops and collaboration with industry, new approaches to seafloor mapping that would particularly enhance efficiency and coverage. Among the new technologies to be examined will be the possibility of low-powered echo sounders deployed on gliders or ARGO floats, the possibility of fleets of long-range AUVs equipped with interferometric swath sonars, and autonomous surface barges or sailing vessels capable of long-duration, ocean-wide transits (Figure 10). These autonomous platforms would be controlled from shore and transmit data back to shore via satellite communication links allowing 24/7 global operation with minimal human supervision. This concept becomes particularly important as we envision thousands of hours of data collection in remote areas of the world oceans where crewed vessels would be particularly inefficient given the need for long transits to accommodate crew changes and the potential monotony of long data collection campaigns. In the more trafficked regions of the world ocean, crowd-sourced bathymetry offers tremendous potential. Using crowd-sourced bathymetry is not new to GEBCO. Bathymetry provided by the Norwegian company Olex comprised a significant source for the compilation of the International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 3.0 grid released 2012, as well as in the latest GEBCO_2014 grid. The Olex depth measurements originate from their automatic charting system installed primarily on fishing vessels. Other companies using a crowd source approach have now also entered the market. Small and easy to install NMEA-loggers storing depths from any ship echo sounder already exist and are being further developed. Such methods could be used on a global scale, through adoption by shipping companies, cruise ship companies, and recreational boaters for example. IHO has a crowd-sourced working group with substantial GEBCO engagement. This working group is tasked to draft recommendations for the minimum metadata to be provided along with depth measurements, and discuss available technologies, post-processing, as well as online upload technologies and storage. The gap between the coastline and where depth measurements exist on the continental shelf is large in remote areas on Earth. Surveying of these areas using conventional methods from ships, and even with AUVs, may be enormously challenging and expensive. LIDAR is highly effective and relatively inexpensive for large-scale regional mapping but is limited to areas of relatively clear water.