Mission identifier:	G002
Mission name:	Onslow Bay transect
Sponsor:	CORMP
Vehicle:	Pelagia
Deployment began:	26-Sep-2005 11:05 EDT
Location:	34 08.8N 77 42.4W, about 6 miles ENE of Masonboro Inlet, near 'ILM2'
Planned end date:	17-Oct-05 est.
Mission coordinator:	Jeff Williams
Phone:	910-962-2470
Email:	williamsj@uncw.edu
Science coordinator:	Wendy Woods
Phone:	910-962-2393
Email:	woodswendy@woodswendy.com
Description:	To provide concurrent glider/ship/buoy data for glider instrument calibration. Documentation of Hurricane Ophelia impact and post-hurricane response.  Observation of horizontal and vertical patchiness near permanent buoys. Satellite data ground truthing with large-scale chlorophyll fluorescence data.
Date	Today's Report
14-Oct-2005	Today the glider was successfully recovered aboard the R/V Cape Fear.  Mission files will be downloaded to help determine the cause of the southward track.  The strong currents and deteriorating weather conditions led to the decision to recover the glider a few days early.
13-Oct-2005	Over the past 24 hours the glider has been driven southward by current flow.  The goto list on the glider has been changed to force the glider to head toward ILM3.  It is hoped the currents will be less severe offshore and the glider can get back on track.  Also, several more OB1V03.MI missions have been sequenced should the glider abort this mission.
12-Oct-2005	Today the glider aborted the mission around 11:00 am.  The glider restarted the mission and headed back toward ILM2.  Webb has a software fix for this bug, and the update will be done when the glider is recovered.
11-Oct-2005	Today we have had good comms every 4 hours.  The glider is headed toward ILM3 on a good heading.  There have been no aborts or erratic changes in heading.
10-Oct-2005	Today we have had good comms every 4 hours.  The glider reached ILM2 this morning, around the same time water samples were taken aboard the R/V Cape Fear at that location.
9-Oct-2005	In the past 24 hours, weather has improved and we have had good communication with the glider.  The track toward ILM2 has been a little erratic in the past day.  This may be due to the long surface time spent sending files and the 2 aborts in the previous couple days.
8-Oct-2005	Today the glider seems to be catching up on the large number of files it is trying to send back.  However, the glider did abort the mission again this morning due to a prolonged same depth measurement.  The glider began the OB1V03.MI mission again and proceeded toward ILM2.
7-Oct-2005	Today we had extremely stormy weather in Wilmington and offshore.  This most likely contributed to the communications problems we have seen today.  The glider is trying to send a large number of files when it calls in, around 20 this morning.  At approximately 10:22 this morning the glider aborted the mission due to a same depth measurement.  The glider successfully began the sequenced OB1V03.MI mission.
	After the restart, the glider made a sharp turn toward the north.  The subsequent gps fixes show the glider turning back to the west, in the direction of ILM2.
6-Oct-2005	In the past 24 hours, we have had good consistent comms every 4 hours. The track is proceding very nicely towards the western waypoint near ILM2.
	Forward velocity is averaging only about .42 km/hour or 0.11 m/sec. Water velocity calculations suggest that there is a persistent east-setting current. This is doubtful and I suspect that our actual forward progress is less than predicted, perhaps because of our shallow operating depths. (Water velocity is inferred from calculations derived from measured position vs. predicted.)
5-Oct-2005	Yesterday around 5PM I stopped the current mission, downloaded outstanding data files, and modified the mission description to cause 1 hour GPS intervals and 4 hour comms intervals. When restarting the missions, I sequenced the mission OB1V03.MI five times. this was recommended by Webb to solve the known bug that caused our abort yesterday early morning.
	The new mission is running fine and the data show the glider surfacing every hour - and occasionally more often from bad altimeter hits - and doing comms every four hours.
4-Oct-2005	At about 3AM this morning, the glider aborted the running mission, reporting "Same Depth" for 120 seconds. This would typically indicate that the glider had grounded due to a malfunctioning or incorrectly programmed altimeter. This doesn't seem to be the case however, and the depth readings look suspect. Perhaps the pressure sensor has failed, or a giant squid is holding it.
	I downloaded all outstanding mission logs, recalibrated the pressure sensor, and sent her back on her way at 8:40 AM. Expect a four-hourly report.
3-Oct-2005	Late in the afternoon on Friday, the glider reached the western waypoint at ILM2. I reprogrammed the mission to prevent communications during surface events due to bad altimeter hits. I could not adjust the altitude and depth parameters sufficiently to prevent the bad altimeter hits because of the shallow operating depths at the western waypoint.
	We reduced the real time data rate from every 5th yo to every 6th yo. Other parameters were decimated from every 2 seconds to every 4 seconds. A heading parameter was added (every 60 seconds) to aid in understanding the erratic track behavior. File sizes are under 100K and surface comms are now 10-15 minutes at each event.
	Fundamentally, the glider seems to be functioning well. It is very conceivable that tidal influences, coupled with the 4-hour communications/location cycle, are resulting in the wandering track that we're seeing. Since progress was good over the past 48 hours, we'll leave this mission in place until the glider returns inshore again.
30-Sep-2005	The glider is continuing west towards ILM2. Unfortunately, it again experienced a large digression to the east - this time over 1.5 miles - before resuming its westward track. I'm in communication with Webb over whether this anomalous behavior is due to glider guidance problems or is truly the result of a strong water current.
	Bad altimeter hits caused a number of unnecessary surfacings yesterday evening, but over night were not seen. Again, Webb has been asked to comment on a suggestion for eliminating this behavior.
	Data transfer times are running about 15-20 minutes each 4 hour interval. We will further decimate the telemetered data to reduce the communications time and energy. This change will take place when the mission changes are implemented to solve the unwanted surfacings problem.
29-Sep-2005	The glider behaved well overnight. We had a large number of false surface events between 8PM and midnight last night. I’m working with Webb Research to resolve these.
	The glider is heading west towards ILM2. At the current rate it should arrive at the waypoint tomorrow morning. If I can resolve the false surfacings and this eliminates unnecessary surface drift time, it’ll speed up.
	Good news. Aaron Alexander of NURC has set up a web page that reflects the current status of the glider mission. This is not yet an automated process; it still requires a couple human steps, but it’s a good place for you to check on status. We will endeavor to keep this current.
	www.uncw.edu/nurc/auv/glider/currentmission.htm
28-Sep-2005	Not to put too fine a point to it, but I’ve redefined this to be mission “G002” allowing us to use “G001” as the first glider mission identifier for sea trials and tests. Attached is an Excel spreadsheet that summarizes the mission. I’ll use this as a status report vehicle.
	If there’s anything you’d like to see added to these regular reports, please let me know. Also if anyone else ought to be on the distribution (of if you’re tired of getting these) let me know and I’ll update the dist list.
27-Sep-2005	Thanks to help from Webb Research, I was able to change the dockserver configuration and take control of the glider during a surface interval in spite of the short duration Iridium connection. Webb’s analysis of our mission plan is that a 60-second timeout for Iridium is too short and we have lengthened it to 300 seconds. (300 is what it should have been in the first place; I don’t know why we chose 60, but there it is.)
	At approximately 3:45 PM I aborted the first mission, rebooted the glider, and uploaded a modified mission with the 300 second timeout.
	I then downloaded all of the decimated data files that had been generated in the previous 29 hours. It took over two hours of continuous data transmission to receive these files. The good news is that the Iridium connection was rock solid for two-hours. After a short glitch and reconnection, it worked fine for the rest of the time. On the other hand, our definition of “decimated data” is resulting in almost two hours of transmission time in every 24 hour period. As a result Wendy and I inspected the received data and have further reduced our definition of “decimated”.  We will monitor the future transmissions to see how much we reduced this surface (non-data gathering) time.
	I uploaded the new decimated data definition file (sbdlist.dat).
	I started the new mission – with the same waypoints – at 8:00 PM. The glider should continue to phone in every four hours.
	Attached is a plot of the surface events so far. The effects of an increasing north-setting current are evident. The marks ‘ILM2’ and ‘ILM3’ are only approximate. I will correct them tomorrow.
27-Sep-2005	Yesterday (26 Sep) we deployed the glider from R/V Sea Hawk, about 5 miles offshore from Masonboro Inlet. It’s programmed mission is to fly a reversing transect between that point (near ILM2) and a point 5 miles east of ILM3 (about 27 miles offshore). The transect repeats indefinitely until we cancel the mission.
	The glider is programmed to come to the surface and communicate with us at four-hour intervals and at each waypoint. Since the release at approximately 11:32 AM, it has successfully phoned in at each four-hour event save one. GPS fixes sent during those communications indicate that the glider is proceeding well along its programmed track at a speed of approximately .25 m/sec (1/2 knot). Occasional ARGOS satellite transmissions also confirm the glider’s position.
	A problem with the Iridium communications subsystem is, however, truncating each phone call after a very short period. No real time data telemetry is occurring as a result. Webb Research has been informed of the problem and relevant files have been sent to them for analysis.
	The glider mission will continue for the time being. We will monitor the Iridium communications to determine if variability in the satellite network seems to be influencing our connections. Also, we will gain experience in predicting the glider’s velocity and adaptability to ocean currents. This will be important for the recovery mission since we will have to have a boat “in the right place at the right time” to hear it. Depending on Webb’s report, it may be feasible to reprogram the glider in situ to resolve the communications problem.
	Tests prior to the mission suggest that the science sensors are working and data are being collected. It is unfortunate that we cannot observe these data in real time, but upon recovery all data should be available.