CTD 0156

Recovered by the British (Tim) out of BAS Rothera Station
Sat Jan 21 12:48:28 2012 MT: 65

Single yo\'s restored control. Not sure why it was overshooting waypoints. Worth investigation, wonder if the currents changed to favorable and that caused it.

Placeholding at RaTS site, 30 deg dive and climbs to hold position better since its so deep and narrow area.

Glider getting a bit squirrelly, not exactly sure why. Setting the no_comms to 1.5 hr and 3 hour. Also only doing single yo\'s.

Adjusted waypoint a bit SW to re-adjust approach.

Slowing glider down, don\'t want to cover too much ground overnight since we\'re in safe spot.
+190 / -190

New set of waypoints to pass by Rothera to RaTS site. Will need to modify in the morning.

2.5 hour missions

Also took out of the mission to help catch up the TBD\'s. We drifted about .75 km at the surfacing.

u_min_water_depth 30
u_alt_reqd_good_in_a_row 6

Switching to no_comms missions due to shallow depths (4 hour and 6 hour). Shortened TBD a bit, 16 sec sampling. Backing off climb inflection depth by 3 m to 15 m again.

Final goto list is set, we\'ll see if she tracks it.

Flight Test:
12 to 40 m envelope, 10 yo\'s
max buoyancy drive
.454 rad dive/climb (AP Pitch)

ru26d-2011-356-1-317 (0323.0317)

Flight Test:
12 to 30 m envelope, 10 yo\'s
max buoyancy drive
.454 rad dive/climb (AP Pitch)

ru26d-2011-356-1-319 (0323.0319)

ru26d is getting to about 6 meters deep with inflection set at 15 m, or about 9 m overshoot.

On dives, it is overshooting about 10 m.

D .49 in
C -.1 in
(good starting point for fixed battpos, full buoyancy drive)

This information will be helpful when it shallows

!!!!!
u_min_water_depth 500
!!!!!

Must change if we no longer do the place holding mission!!

Taken from ru26d\'s previous deployment:
According to datasheet, we have 30 AH batteries nominal.
Derating:
Temperature plot (datasheet) says 23.3 AH at -2 C which is about 22% derating
Average current is about 277 mA
Lets derate 1 year for shelf life, 3%, and lets say 25% derating for safety:
30 Ah * .75 * .97 = 21.825 AH
We have 26 x 3 DD cells, so total AH is 26 * 21.825 = 567.45 AH

Back to slow down
-175, +155 cc

Turning around towards Rothera, full speed.

Ice beginning to show signs of breaking up south of Adelaide.

u_min_water_depth 325 !!

Glider missed a surfacing and came up on TWR for no_comms.

Nothing super abnormal in missed surfacing except in surface dialog: no gps, fin errors, no iridium connect. Could have been ice?
Segment: ru26d-2011-356-0-2.mlg

MBD for the segment is 500 KB.

Changed pitch deadband to 5 degrees.

Slowed down glider a bit more as in previous note.

Starting to save power because of 2 things:
1) uncertain recovery date (Rothera ice delays, etc)
2) uncertain battery life (Silbo issue)

+- 200 cc dive,climb overnight
-175, +155 cc now

Strange ice outcrop on SAR, sending cross shelf offshore for the night. Early returns causing issues, need to try to eliminate the early hits. Not sure how to do that quite yet, might set min water depth for overnight as well.

Added a zig-zag to center of Adelaide island as per Mike Meredith recommendation for following APCC.

u_alt_reduced_usage_mode 0

u_min_water_depth 150
sampling occurred

Added m_raw_altitude to SBD

Strong currents, coming back along most of the same line, except going to start heading to Rothera at around mid-shelf.

Double yo\'s
TBDLIST: 12 sec data (to save more TBD size)

Flying into the current overnight to gauge its strength.

Single yo, 1km, trying to catch up on files.

Surface drift test, .45 knots @ 42 deg (~ 1 hour test)

Copied TWR log files to RU

ru26d got into a new water mass. It also starting getting many false altimeter hits. Getting into uncertain depths so attached is kmz for depths for GE. The white should be 200 m and each color and or bathy line after that is 100 m deeper

Setting u_min_water_depth to 250 m

A bit aggressive but we did have some false hits around 250/300 (I think false...)

Verified autoexec.mi.

8 hour no comms, 3 yo\'s
Heading to 600.100 line, and then onward to 800.2

Added ctd41cp_timetamp to TBDLIST

Inflection distance 7-8 m at surface, < 15 m at depth.

7 hour no_comms, extended waypoint parallel to LTER grid once out of basin

Likely reaching 1km on 2nd dive.

3 hour no_comms, diving 2 dives to full depth, likely only going to go 500 m each dive or so tops.

Will increase no comms maybe in 1 or 2 surfacings once we\'re in the basin.

Glider deployed by Travis Miles out of Palmer Station.

Science payload:

ctd-194
bb2flk-696
optode-1296 (ud_134 optode)