DRI Update: 10 February 1999

As we move closer to our experiment (SAX99) in Oct-Nov, you can expect to receive updates at least monthly. I will start this update with some follow-up items from the Acoustics Workshop at APL-UW in November.

1. At the workshop Ellen Livingston described the need to supply ONR with an environmental assessment of projected sound levels for SAX99. I have received input from investigators on their source characteristics. Beyond this, the key issue associated with making an assessment is to determine sound level criteria that are acceptable to the appropriate regulatory agencies, based on the marine animals that may be affected. This has been a problem in the past, since guidelines have not been established for use by the acoustics community. Fortunately, it appears there is progress being made on at least provisional guidelines. Both Jim Miller at URI and Roger Gentry at NMFS have supplied helpful information, and my interpretation is that we should not have a major problem with environmental impact. However, I am still waiting for some clarification, and will wait on that clarification before distributing details.

2. I mentioned in November that Tony Lyons, now at SACLANTCEN, was interested in participating in our experiment with his new digital stereophotography system to measure bottom roughness, providing this could be worked out. Tony's participation remains a definite possibility, though Tony may not be present himself. He is now coordinating with Kevin Briggs at NRL, and the hope is that his system can be shipped over and utilized during SAX99.

3. At the workshop Kerry Commander described Jim Christoff's SAS system and indicated that efforts were under way to arrange flyby-type measurements at the DRI experiment site. This participation is now set, and consideration is being given to laying down a target field during tests in March to allow natural target burial to occur. [This would involve some risk, since the site location will not be set precisely until the site survey in July.] Peter Dahl at APL-UW has interest in surface bounce modeling as it applies to the SAS measurements. Apparently someone (identity not recorded) at the November workshop indicated willingness to help with a Met buoy. If anyone has info on this, please let me know.

4. The impact of last summer's Hurricane Earl on the Panama City site was discussed. Mike Richardson reported on NRL observations which showed mud deposits overlaying the sand in many places after the hurricane. One concern is whether winter storms will sufficiently wash away the mud to give most of the site the desired sandy sediment. The need for a quick-look survey in the spring to assess the sediment condition was also discussed. Mike has arranged for such a survey in April in conjunction with measurements being made near the site under a separate project headed by Steve Stanic.

5. Mud inclusions may also be present in the upper meter or so of sediment as a consequence of deposition during storm events in previous years. The need to better understand the occurrence of such features was discussed at the workshop. Accordingly, Joe Kravitz has arranged with a group at USGS in St. Petersburg to take a set of vibracores in and near the tentative site. This work is being coordinated with Peter Fleischer at NRL, who will participate. These measurements are imminent.

6. The next DRI workshop is tentatively set for June at NRL-SSC. This will be an opportunity to discuss details associated with the site survey in July and the main experiment in October-November. Mike will be polling for acceptable dates in the near future.

7. It would be useful for all of us to have available a written description of the DRI program, including a brief summary of projected work (with progress to date) for each of the PIs. Thus, I am asking for input from each PI in the DRI program, with a due date of 2 April. I think the goal should be to keep each project description short, perhaps two pages, but without hard constraints. To clarify the request, we at APL-UW will prepare an example based on some of the work here, and make it available to those affected by early March. I will assemble the material submitted, and prepare an overview of the program. My hope is to distribute this program summary before (or perhaps at) the DRI workshop at NRL-SSC in June. I will provide a more detailed request when sending the project description example.

8. We also need to develop a detailed experiment plan in order to schedule and coordinate activity on board the Seward Johnson and the Pelican and for measurement and diving activity in the water. This is just a heads up that I will be requesting in more detail at a later date a proposed plan from each PI (to be due about 1 May), and we can iterate from there to develop a draft experiment plan. Diving issues will be addressed in the next DRI update.

9. The site survey will also be addressed in the next DRI update. For now, Kevin Briggs (POC for the site survey) would like it known that both loading and unloading is now scheduled for Panama City: loading on the morning of 7 July and unloading on the evening of 20 July.

10. We intend to develop a web site at APL to post information related to SAX99 and the DRI program in general. My inclination is to make this a functional site, mainly of interest to participants. Thus, it would include all DRI updates starting with this one, meeting schedules, ship schedules, deadlines, and so forth. At this point, I am not inclined to develop a slick program advertisement for the rest of the world. However, I am interested in hearing opinions on web site philosophy, and I will see where that leads. I assume the program summary mentioned above would be posted, unless opinion develops to the contrary. We could restrict access using passwords, but I suspect many would find that overly cumbersome. Reaction?

11. Finally, at the November workshop Jeff Simmen mentioned the possibility of IEEE special issues. There are two IEEE special issues of interest to the DRI. The first will be published in the summer of 2000 on high frequency acoustics. I am not sure of the precise scope, but it is considerably broader than the DRI program. The editors will be Jeff Simmen, Ralph Goodman, and Steve Stanic. Jeff has suggested that we submit two overview articles, one focused on acoustics, the other on environmental measurements. For the time being, I will be the POC on the first article, and Mike on the second. The goals for these articles will be to give overviews of the DRI program and of SAX99, and time constraints will limit coverage of experimental results. The second IEEE special issue is set for a summer 2001 publication date, and it will be largely devoted to DRI papers. Paper submission will be in the fall of 2000, about one year after the experiment, and about the time of an expected ASA special session on SAX99. Mike and I will be the editors. In addition to these special issues, I would encourage JASA or other journal submissions on an individual basis as work on selected topics is completed.