Ice Profiler Processing Toolbox

The Ice Profiler Processing Toolbox provides everything required to process and analyze raw data acquired with the IPS upward-looking sonar instrument including:
  • Software for decoding, editing and visualizing measurement data
  • A user’s guide with detailed information on each data processing step
ASL has evolved the toolbox over many years of processing IPS datasets and continuously updates the software and documentation. Converting raw IPS data to fully quality controlled time-series of ice draft and other measurements involves many steps and requires familiarity with physical principles of underwater acoustics and oceanography. The Ice Profiler Processing Toolbox software and documentation provides users the necessary guidance and tools and is suited to novices learning the IPS instrument and data and to experts requiring an efficient data processing method

Ice Profiler Processing Toolbox Content
Purchase of the Ice Profiler Processing Toolbox includes:

software Software

The Ice Profiler Processing Toolbox contains software tools for processing the acoustic (multiple target range, amplitude and persistence) and ancillary (pressure, tilt, temperature) time-series that are acquired by the IPS. Processing includes decoding from raw instrument data, signal anomaly detection and removal, calibration of range for variations in sound speed, fusion of signals to compute ice draft time-series, and fusion of ice draft time-series and ice velocity time-series to compute two-dimensional ice draft spatial-series. The toolbox is available as a desktop application for Windows with easy-to-use graphical interfaces.

  • asl_icevelspatial – Edit ice velocity time-series and visualize effect on ice draft spatial-series.
  • axesscroll – Visualize any time-series with graphical scrolling and zooming.
  • asl_calcbetafromrecnum – Calculate instantaneous sound speed corrections.
  • asl_calculatedraft – Calculate ice draft.
  • asl_despike – Find and remove anomalies from time-series.
  • ASL_ExtractData – Extract data channels from multi-channel datasets.
  • ASL_MaskData – Replace episodes within a time-series with flag values.
  • ASL_MovingAverage – Apply filters to time-series.
  • ASL_OWCalibration – Create sound speed correction time-series.
  • asl_patchdata – Patch an episode from one time-series into another.
  • ASL_PlotAll – Create and print multi-panel time-series plots.
  • ASL_Pressure2WL – Compute water level from IPS pressure time-series.
  • ASL_RemoveAtm – Remove atmospheric pressure contribution to IPS pressure time-series.
  • asl_scaledata – Perform customized computations on data channels.
  • asl_doublebounce – Detect and remove double bounce effects from IPS range time-series.

my picture User's Guide

The purpose of the User's Guide is to enable users of the Ice Profiler Processing Toolbox to develop appropriate procedures for processing IPS data. The successful processing and analysis of IPS data requires a solid understanding of the instrument itself and of the physics of underwater acoustic and oceanographic processes. Although this manual recommends a processing method it is by no means restrictive. There are many ways to process IPS data and the reader may find that she/he may wish to alter or append to the methods suggested in this document. The optimal data processing and analysis approach may depend on such factors as:
  • the sea-ice and oceanographic regime of the study area;
  • platform (e.g. bottom moored or AUV) dependent issues;
  • the available computer environment and resources.
A sample data set is used throughout the User's Guide so that the reader may observe the various stages of the processing procedure.

1 Introduction and principles of operation
1.1 Overview
1.2 Background and history
1.2.1 Upward looking sonar (ULS) measurements of ice drafts
1.2.2 Ongoing development of the IPS4 at ASL
1.2.3 Development of the IPS5
1.2.4 Related products
1.3 Overview of underwater acoustics
1.3.1 Principles of operation
1.3.2 Sonar equation
1.3.3 Transmission losses and time varying gains
1.3.4 Target strengths
1.4 Requirements for measurement of ice draft
1.5 IPS4 Instrument particulars
1.5.1 Acoustic transducer
1.5.2 Time varying gain (TVG)
1.5.3 IPS4 target selection algorithm
1.5.4 IPS sonar equation spreadsheet
1.5.5 Other IPS4 measured quantities
1.5.6 Burst sampling feature
1.5.7 Multi-phase operation of IPS4
1.6 IPS5 Instrument particulars
1.6.1 Acoustic transducer: 420 Khz (nominal) acoustic frequency
1.6.2 Time varying gain (TVG)
1.6.3 IPS5 target selection algorithm
1.6.4 IPS sonar equation spreadsheet
1.6.5 Other IPS5 measured quantities
1.6.6 Burst sampling feature
1.6.7 Multi-phase operation of IPS5
1.7 Data processing overview
1.8 Running ASL IPS Processing Toolbox™ programs
1.8.1 Standalone ASL IPS Processing Toolbox™
1.8.2 Some general guidelines for data processing
2 Pre-processing
2.1 Raw data decoding
2.1.1 Ipslink
2.1.2 Ips5Extract
2.2 Data visualization using axesscroll
2.3 Data visualization using asl_plotall
2.3.1 Plotting the acoustic data
2.3.2 Plotting the ancillary data
2.4 Clock drift calculation
2.5 Data cropping
2.6 Null target replacement using range at maximum amplitude for IPS5
2.7 Crop excess channels
2.8 Initial acoustic range examination and classification
2.9 Automated detection and removal of erroneous or suspect data
2.9.1 Acoustic range time series
2.10 Patching flagged/open water data back to file
2.11 Manual detection and removal of erroneous or suspect values
2.12 Pressure time series
2.13 Tilt time series
2.14 Bottom temperature time series
2.15 Pressure Correction
2.16 Atmospheric pressure removal
2.17 Meteorological data and source book
3 Computation of ice draft time series
3.1 Definition of ice draft and practical considerations
3.2 Computation of water levels
3.3 Computation of total instrument tilt
3.4 Water level and tilt magnitude smoothing
3.5 Estimation of the speed of sound over the water column

my picture Technical Support

Purchase of the toolbox includes up to eight hours per year of technical support from ASL’s data analysts and software engineers.
my picture Updates

ASL’s data analysts use the toolbox themselves and continuously update the software and documentation. Purchase of the toolbox includes these updates for the first year. An annual maintenance subscription provides ongoing access to these updates.
Please contact us for pricing and delivery details by email at
A four day training course on the processing and analysis of IPS data at ASL Environmental Sciences is available upon request. The training course cost includes a license for the Ice Profiler Processing Toolbox. Customers who took training courses with ASL will also be offered reduced rates on future software assistance. Please contact us for details by email at