Checking for Correct Raw Data Storage
On this page:
Online checks
Observation Physics Display
On any project, an important first task is to determine if you have selected the correct drivers in the template database to decode the incoming data.
The Observation Physics Display is the primary place to check if data is arriving and being decoded properly.
For all systems, check whether the time and observation values are updating steadily; this is an indication that all is well. If data is not arriving or not decoding it will not appear in the display or it will be highlighted in red.
For a multibeam or sidescan system that has raw data storage options enabled, the Raw column in the display shows which packet types are being decoded.
The Quality column shows the size of the packet in bytes. The image below shows the packet types for a Kongsberg EM multibeam:
The Observation Physics Display menu can be reached through: Controller - Options - Displays - Add Display.
Alert Display
Another important display to set up early in the survey is the Alert Display. As the picture below indicates, various types of alerts are available for configuration.
The I/O category is used to monitor reception of the various data on their assigned ports. By setting a time out number of seconds, the user is immediately informed if data flow has been interrupted.
While the Observation Physics Display is not particularly of interest as a permanent window taking up valuable screen space, an Alert Display can be configured to reside in the bottom bar as a 'traffic light' icon.
In normal circumstances the light stays green until one of the test conditions is not met. At that point the display pops up maximized showing the culprit condition highlighted in red making it quick to identify, if not remedy.
Many different types of alerts are configurable, thereby automating a significant portion of system monitoring; this allows the surveyor to concentrate on data coverage and quality.
The Alert Display menu can be reached through: Controller - Options - Displays - Add Display.
Raw Multibeam Display
The function of the Raw Multibeam Display is to provide an online check of raw multibeam values. It visualizes various observations that are received from a multibeam system:
- Bathymetry
- Water column data
- Average beam intensity ('per-beam') (A button)
- Beam Quality (or detection flags)
- Intensity Beam Time Series (e.g. Snippets/Seabed Imagery) ('I' button)
Info
Note that not every multibeam system is capable of delivering water column data and Intensity Beam Time Series; this depends on the brand and model (the major brands will support it though).
The observations are displayed completely uncorrected for heave, pitch and roll or any other adjustment, i.e. 'as raw as possible'.
The Raw Multibeam Display menu can be reached through: Controller - Options - Displays - Add Display.
Offline Check on Database Content
When presented with a dataset with which you are unfamiliar, or if wanting to confirm that the data you thought was recorded is actually there, go to the Raw Data Manager, right click on a *.db file and select the Database Properties.
A new tab has been introduced that shows the Raw Data streams recorded in the database.
This is currently the only way for a user to see if the DB contains raw data, assuming the user does not have the Db Inspector tool.
