Using Control Points

This section describes how to use monitoring points in Delph INS Subsea to aid the inertial processing with known positions observed by the user during the survey (for instance computed from imagery data).

1.

Create a text file containing the update information in GPS text format (time stamping (with respect to UTC and not GPS time), latitude, longitude, altitude and associated standard deviations). See the GPS.txt file stored in the Doc\User defined template directory in the Exail folder.

2.

Load this text file in Delph INS Subsea; it is converted in XPF file by GenericText2Xpf using the definition file. See GPS.gtd.html file stored in the Doc\Generic Text Definition directory in the Exail folder.

3.

Add a new GPS aiding sensor and assign in its settings the GPS channel of the XPF file containing the data as data source.

4.

Setup the lever arms of this fake GPS as if it were a real GPS.

The standard deviations associated to the data must not be too low and must be consistent with the accuracy of the measured data.