Summary
Sea ice observations are difficult to obtain in sufficient temporal and spatial resolution. Several observational techniques have been used to build a sea ice record of ice concentration, ice extent, and ice thickness among other things. Satellite measurements are varied in their capabilities (e.g. resolution in pixel size and timing of passes) and in how genuine the results are. Ship observations have become a standard procedure to build a database but are limited by scheduled tracks (often in ice free or ice limited areas) and the small amount of coverage they are capable of. On the other hand, helicopter video observations are able to cover much larger regions and still have the benefit of a comparatively high resolution visual observation. The ASPeCt process has been used for some time now to characterize ice conditions during cruises. This process has been extended to helicopter video data and the technique is presented here. While there are limitations to using helicopter video data to detennine floe size or ice thickness, there are methods using nearby ship observations as a tie point that can be used to provide a reliable estimate. While a significant amount of time is needed to manually process the videos using the ASPeCt method of sampling along a transect, reliable estimates of the complete set of ASPeCt parameters have been made and it has proved to be much less labor intensive than digital processing of the entire tape for ice concentration only. There is also good agreement between the estimate of ice concentration by ASPeCt sampling and the concentration obtained by objective image processing of the same tapes. The two methods have proven to give very close results (a standard deviation of ::1::3.3%T).w o sets of observation data from helicopters have been placed in the ASPeCt data base to date. With workshop discussion, we hope to show this type of analysis is sufficient for processing helicopter photography or videos, and start to catalog data sets that may already exist to provide expansion of the existing data base. For any future filming, we will review the particulars necessary to gather data for input into the database in future.