Qimera Import Navigation Configuration Dialog

How to Start

  • Add Binary Navigation Files option of the Source menu in the Main Menu bar.

What it does

The Navigation Import Configuration dialog is for importing navigation data logged or processed with third party software. See Position and Motion Formats for supported data types.

General Description

The dialog has several sections, these are explained below.

POSPac Data

When importing POSPac SBET files, 'sbet' must be part of the base name of the file.  The base name is the part of the file path preceding the extension and after the directory.  If you have an associated RMS file, it must have the same naming except that 'sbet' is replaced with 'smrmsg' (and it must reside in the same directory).  If this naming convention is not used, Qimera will not be able to auto-recognize the file type.

Vessel

Navigation data must be attached to a vessel. Simply select the vessel from the dropdown for which the navigation is being imported.

Position, Motion, Depth and Pressure System Reference

All imported navigation data must be attached to a new system. If you have not imported navigation data previously in the project you will need to create new systems for import data types. Otherwise you can use previously configured systems. After systems are created they can be further modified in the Qimera Vessel Editor.

Creating a new System

  1. To create a new system click the  button next to the system drop down.

    Qimera New System Dialog
    The New System dialog (shown below) allows you to specify a name, system type and available settings for the system type. If creating a new system for ASCII or Binary Navigation Import the System Type will be preconfigured.

    Either enter the appropriate LocationOffsets, and Uncertainty property settings or use Copy Values from Existing System... to copy and edit values from an existing system.

    Copy System Properties

    When Copy Values from Existing System... is clicked in the New System dialog the following dialog is shown. You can only copy from existing vessel systems.

    The set of properties that are allowable for copy will depend on the type of system you are creating and the type of system that you are copying from.  For example, you cannot copy the angular offsets or uncertainties of an existing motion sensor to a newly created position system.  Once you have chosen which properties you wish to copy, these values will be used to populate the appropriate fields in the New System dialog.  You can edit these values after you have copied them.

  2. After reviewing and accepting values in the New System dialog the new system should be shown in the dropdown.  Check the data types that are to be extracted into the system.

Using an existing system

If you previously imported ASCII data the systems created during the import will be listed in the System drop down. Simply select the appropriate system and check the import data types.

Using an existing systems means all settings will be identical. If different uncertainty or offset settings for the system may be needed it is advisable to create a new system with copied settings.

Priority

When checked this option will make the imported systems take the highest priority in the Processing Settings Dialog.

This option is checked by default.

For formats that have depth and pressure observations, such as Kongsberg NavLab, depth will alway take the highest priority. If pressure is desired to be highest priority, you will need to uncheck the Depth Source Priorities in the Processing Settings Dialog.

Acquisition Date Reference

For formats that use relative time references, such as POSPac and POSMV, an absolute time reference is needed. The time is stored as GPS seconds-of-week so the week in which the data was logged is needed.

The GPS Week dropdown shows a calendar date picker. Pick the Sunday of the week during which the data was collected.

Based on the picked week the computed start of the earliest file being imported will be shown below the dropdown.


For formats that store the full time reference, such as Kongsberg NavLab, SRH (PFreeHeave), SBTC and SBIC, the Acquisition Date Reference will only show the Start of File and Day of Year for reference. No need to pick the GPS Week.

SBTC note: SBTC navigation files are in GPS time. Qimera uses a lookup table to compute the number of leap seconds between UTC and GPS time. If the table is not up to date, a positional data shift may be noticeable in the surface.

To fix this shift, the user can apply a latency value of 1 second in the vessel editor and re-nav the source files. This latency value should be applied to the new Position and Motion Systems created upon import of the binary navigation.

Acquisition Coordinate System

Specify the datum of the data being imported. Navigation data will be converted to the project datum specified in the Project Properties Dialog.

Transform heights to Project Coordinate System

This is checked by default. If unchecked the heights with have no geodetic transform applied and thus be referenced to the Acquisition Coordinate System. 

Delayed True Z and True Heave

When importing from an Applanix POSMV file, you have the additional potential of importing Delayed True Z or True Heave if the appropriate packets are logged to the file.


Delayed Heave

When importing from a Kongsberg PFreeHeave (SRH) file, you have the option of importing PFreeHeave if the appropriate packet is looged to the file.



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