Open Navigation Surface

"The Navigation Surface (DOWNLOAD [2.56M]) paradigm is a design for a databased alternative to traditional methods of representing bathymetric data. It aims to preserve the highest level of detail in every bathymetric dataset and provide methods for their combination and manipulation to generate multiple products for both hydrographic and non-hydrographic purposes. The advantages of the method over traditional schemes are such that a number of commercial vendors have adopted the technology. However, this means that there is a strong requirement for a method to communicate results in a vendor neutral technology. The Open Navigation Surface (ONS) project was designed to fill this gap by implementing a freely available source-code library to read and write all of the information required for a Navigation Surface. 


The Navigation Surface concept requires that in addition to estimation of depth, we must also estimate the uncertainty associated with the depth. In order to make the system suitable to support Safety of Navigation applications, we also require a means to over-ride any automatically constructed depth estimates with 'Hydrographer Privilege', essentially a means to specify directly the depth determined by a human observer as being the most significant in the area (irrespective of any statistical evidence to the contrary). Finally, we must provide data on the data, or metadata, which describes all aspects of the data's life from methods of capture to processing methods, geospatial extents to responsible party. The ONS project provides means to incorporate all of these requirements in a portable, platform neutral, vendor neutral format. 

The Open Navigation Surface (ONS) project came about because of the growing popularity of gridded bathymetry products in the hydrographic product pipeline. Adoption of gridded bathymetry allows for new methods of data reduction, archive, databasing and product creation which can be significantly more powerful than traditional methods. However, there was no extant format for transfering the required information about the bathymetry and its associated uncertainty and other features (e.g., hydrographic operator modifications for safety of navigation, meta-data) between different processing packages. The ONS project is a way to fill this gap; the object of the project starting was to define a file format that has the appropriate components to transfer all of the information inherent in a processed bathymetric object, and to develop a source code base to implement this format. "

http://www.opennavsurf.org/ 

http://ccom.unh.edu/theme/data-processing/nav-surface-and-bags