11/8/93: Weekly Report of the TROV Project

CRS 11/8/93
     
In this past week, we have trained both local and remote operators, and have
made considerable progress in accomplishing the benthic ecology science
objectives of the experiment.

On November 1-2, we trained both local and remote operators to drive the TROV.
Butler Hine and Mike Sims trained in the remote operations of the TROV. Butler,
who had designed most of the operator interface, trained himself by driving the
TROV for several hours by remote control with little assistance from the local
team.  Mike, who had relatively little experience with the remote interface and
none with the TROV itself, was instructed by telephone by Dale Andersen. It was
very much like having a remote driver training instructor.  Dale gave Mike
detailed instructions such as "turn left, a little more, stop".  The attitude
of the vehicle when thrusters are pushing it forward is controlled by the
position of two dive planes.  The position of the dive planes can cause the
TROV to pitch up or down when forward thrust is applied.  Even a minor change
in the position of the dive planes causes a large effect on the pitch angle.
With local control, it is relatively easy to compensate for this pitching by
adjusting with the vertical thrusters.  However, in remote driving there is a
slight time delay, due primarily to switching times in the satellite
transmission.  We have measured this time delay to be approximately .7 seconds.
Remote operators found that it was relatively difficult to compensate for the
pitching upon forward thrust because of the time delay.  Thus, driving by
remote control was judged to be more difficult than using local control.

On the evening of November 1, Jim Barry arrived in McMurdo. Due to weather
conditions, this proved to be the only flight into McMurdo the entire week.
Jim Barry is the Benthic Ecologist from Monterrey Bay Aquarium Research
Institute who is using the data obtained by the TROV to study the Benthic
Ecology of McMurdo Sound. Jim brought along a field assistant, Gage Dayton.
Gage is the son of Ecologist Paul Dayton, who had performed the original
transect survey of the area in McMurdo sound where the TROV is currently
operating.  Continuing in the family tradition, Gage is a student studying
Marine Biology.

      Jim and Gage got their first chance to come out to the Hypertat in
November 3.  They visited the operation and then prepared to do a scuba
training dive with Gage, who had never been diving below the ice before.  Scuba
Divers were Dale, Jim and Gage. The SCUBA dive was performed out of a dive hut
some 50 m away from the current Hypertat location.  The TROV was brought over
to the dive hole so that we could watch the dive.  Since this was a training
dive, the plan was not to swim around.  Dale was planning to perform a
calibration measurement which involved using a measuring tape to get an exact
distance from the TROV. We watched the three divers come down the hole.  Then
something went wrong.  Gage dropped his weight belt, a situation which can be
extremely dangerous because without a weight belt the diver will bob to the
surface.  Both other divers tried to grab it, but Gage was already ascending.
Gage knew what to do, he spread himself out to slow his ascent and exhaled all
the way up.  At the surface, he ended the dive.  Meanwhile, Jim retrieved the
weight belt and headed for the surface to make sure Gage was all right.  Dale
stayed down still trying to complete his calibration measurement, but due to
the other problems in the dive, was not able to finish it on time.  The TROV
acted as Dale's dive buddy while he stayed down for the last part of the dive.

While this dive operation was going on, the weather began to seriously
deteriorate.  We got a call from California saying that video was lost.  Carol
and Jay went up to the roof of the firehouse to check the Laser receiver and
repoint.  While on the firehouse roof, we realized that we could barely see all
the way to the Hypertat. Snow in the air was cutting the visibility way down.
The video transmitter operates in the near infrared and is scattered by
atmospheric particles, such as clouds and snow, much as is visible light.
Thus, when it is snowing, the video transmission back to the firehouse becomes
too poor to give us a good signal back to California. This bad weather
continued through most of the rest of the week and so confined us to doing
mostly local operations.

On November 4, Jim Barry came out and did TROV driver training.  He was an
expert TROV driver just about from the first minute he took control of the
joystick box which controls the vehicle thrusters.  This is consistent with a
phenomenon I have observed earlier.  People who have had lots of experience
working as divers in the underwater environment, but who have not ever driven
an ROV, seem to learn to drive faster than a non-diver.  In addition, an expert
interested in the environment being surveyed with the TROV does not become
fatigued in operating the TROV nearly as fast as a non- specialist operator.
Jim spent the day driving around in the area.  We had chosen the location of
the Hypertat to be directly over our "best guess" location of the Dayton
transect survey sites , but we had been unable to locate the survey sites.  Jim
Barry spent his first few hours of operation driving around and becoming
spatially oriented.

By November 5, Jim had gotten a good idea of the layout of the area and was
able to find the lines and stakes from several of Paul Dayton's transect lines.
The Dayton transects consist of a series of ropes up to 30 m long staked on
either end.  Some of these lines were put in as long ago as the middle 1960's.
By periodically resurveying these areas, one can learn about the long-term
changes in the ecology of the sound.  The ropes and stakes have long since been
colonized by organisms and are well camouflaged.  Jim found that the stereo
helped enormously in finding the ropes and stakes by using their shape to pull
them out of the camouflage.  We began to use the TROV to resurvey the Dayton
transect sites.  This survey consists of driving over the original transect
line at a slow rate at a height of two feet and obtaining stereo video footage
of all the organisms along the line.  Then the TROV is turned and the line is
again driven at a slightly larger height using the downward pointing camera, or
the zoom camera, as a close up lense.  Stereo is still used for driving but the
data is taken with the close up lense.  To get the best data accuracy, each
transect line must be driven several times.

Also on November 5, we gave a remote control demonstration for Mike Meyer,
Exobiology program manager from NASA Headquarters who was visiting the Robotics
lab at NASA Ames. While under control from Ames, a huge jellyfish was spotted
near the surface.  The remote operator ascended and obtained spectacular close
up footage of the creature for over an hour.  We also got some interesting
underwater footage as a drill rig came out and drilled another dive hole near
the TROV. We watched the drill bit come down through the ice.

We finished the week by continuing to resurvey the Dayton transect sites.
Using the TROV, Jim was able to resurvey all of the transect lines that he
could find.  An individual transect line only takes a few minutes to survey
using the TROV. Jim found the TROV video to be excellent for performing the
survey and found the local control method to work very efficiently.

So far, the transect surveys have been performed by flying along fixed lines
and have not required keeping track of the position using the Sharps navigation
system.  These transect surveys were performed by Jim Barry using local control
and no transects have been flown by remote control.  This is because we have
had very bad weather all week and video transmission to Ames has been
intermittent.

The typical McMurdo work week is 7:30-5:30 Mon-Sat. The TROV team has been
largely adhering to this work schedule as well so Sunday is our only day off.
Each Sunday evening, there is a scheduled science lecture open to all the
McMurdo staff and science groups.  This week, the author of this report (Carol
Stoker) gave the lecture entitled "From Antarctica to Mars: Virtual Reality in
McMurdo Sound." The lecture used recent slides of the TROV operation taken here
in the Hypertat, along with overhead slides, and a video tape about the project
produced at Ames Research Center. This lecture was enthusiastically received by
the McMurdo community.
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  Via FTL BBS (404-292-8761) and NASA Spacelink (205-895-0028)
