EKlook

Description

EKlook is an interactive X-window application designed for visualizing and analyzing EK series echosounder data, particularly focusing on matched-filtered traces. It allows users to examine various aspects of the echosounder data, including trace power, phase, bottom detection, and angular response, through a graphical interface with several specialized widgets. The tool supports loading background maps, area files, and sphere target strength models for comprehensive analysis.

Usage 

EKlook [OPTIONS] -prefix <EK_file_prefix>

Arguments

Option Description Default / Example
-v Enable verbose output.  
-mountangle <degrees> Forces a specific mount roll angle (in degrees) for calculations. If used with -guidedepth, it attempts to guess better min/max depths. 45.0
-guidedepth <meters> Forces a specific nadir depth (in meters) for calculations. If used with -mountangle, it attempts to guess better min/max depths. 400.0
-sensitivity <value> Sets the Angle Sensitivity for along and across angles. 10.0
-twowaybeamwidth <degrees> Sets the two-way beam width in degrees. 12.0
-backdrop <orthomap.mos> Specifies an 8-bit image file to use as a geographic backdrop in the position/motion view. orthomap.mos
-areas <AreaMapFileName(s)> Specifies one or more area map files (e.g., .r4 files) for defining spatial regions of interest. custom_rot_mapsheet.r4
-sphereTS <sphereTS_filename> Specifies a file containing sphere target strength data versus frequency for comparison. TSvFreq.dat
-prefix <EK_file_prefix> Required. Specifies the file prefix for the EK data files (e.g., matchedfilted). The tool will look for files like EK_file_prefix.MF_dB. matchedfilted
-forgot Adjusts mindB, maxdB, and trimdB by subtracting 120.0 dB, typically for older data or specific sensor types. Also disables BulkCalibration.  

Interactive Widgets / Views

EKlook provides several interactive sub-windows (widgets) for detailed analysis:

  • ZOOM EK-Trace window: For zoomed-in viewing and analysis of individual traces (managed by EK_ZoomImage.c).
  • FFT EK-Trace window: For Fast Fourier Transform analysis of trace segments (managed by EK_FFT.c).
  • POLAR EK-Trace window: For polar plots of target strength and phase information (managed by EK_Polar.c).
  • BOTTOM Detect / ARC window: For adjusting bottom detection parameters and generating Angular Response Curves (ARCs) (managed by EK_BottomBS.c).
  • Position-Motion EK-Trace window: For visualizing geographic position, vessel motion, and bottom strike points in 2D and 3D (managed by EK_PosMotion.c).

General Interactions

  • Main Thumbnail Image: An overview of the entire file’s trace power, allowing selection of zoomed regions.
  • Power Histogram: A histogram of trace power, used for adjusting display greyscale/color ranges.
  • Mouse Wheel: Scrolls through traces in the main thumbnail view.
  • Middle Mouse Button Click (Main Thumbnail): Selects a currenttrace for detailed analysis in other widgets.
  • Left Mouse Drag (Rubber Banding, Main Thumbnail): Defines a new zoom area for detailed inspection.

How It Works

EKlook functions as a central hub, orchestrating various specialized modules (widgets) to provide a comprehensive interactive environment for EK echosounder data. It loads initial data and configuration via command-line arguments. Once running, an internal event loop (EK_event_loop.c) manages user interactions within the main window and dispatches events to the active widgets. Each widget (EK_ZoomImage, EK_FFT, EK_Polar, EK_BottomBS, EK_PosMotion) then handles its specific data processing, visualization, and interactive controls, updating its portion of the GUI in real-time.

Notes

EKlook is an interactive graphical application. While it takes initial command-line arguments, much of its functionality and analysis is performed through the GUI. The descriptions of its sub-modules (EK_ZoomImage, EK_FFT, EK_Polar, EK_BottomBS, EK_PosMotion) provide more detail on the interactive controls and visualizations available within each specific window.