Export Surface to HTF

Export a selected surface to a Hydrographic Transfer Format (HTF) file.

The HTF file is an ASCII file that can be opened in any text editor (such as Notepad). It consists of three sections:

• HTF Header, which contains information about the survey, such as coordinate system, survey title, date, data density, number of positioning systems, etc.

• Sounding Header, which contains an ordered list of all possible fields for the Sounding Data section and a description of each field. There are 20 default fields in the sounding header. Two additional fields are added during export for beam and profile number. Extra fields can be added, if needed.

• Sounding Data, which contains the exported data on depths and other relevant information. At the start of this section is a Field Population Key. This key assigns a binary value for each of the possible fields from the sounding header to indicate whether the field will be included in the HTF file or not. A 1 means it is included, and 0 means it is not included.

For example: Field Population Key [0000111110000000000] means fields 5 to 9 contain data, while fields 1 to 4 and 10 to 20 contain no data. Fields without data are not written to the HTF file when it is generated.

The HTF export automatically exports TPU depth and TPU position values if these values are included in the surface.

The Export Surface to HTF command launches a wizard. Refer to the linked topics for information on each of the steps in the process.