AIDJEX Bulletin #40 - Polar Science Center - University of Washington

Arctic Environmental Buoy System
Walter P. Brown
Polar Research Lab., Inc.
Edmund G. Kerut,
NOAA Data Buoy Office
ABSTRACT
The AEB is a remote unattended data acquisition
and telemetry system designed for deployment
on ice covered seas. The total system as
presently configured consists of up to 12 AEBs
and a Central Control Station (CCS). The Central
Control Station under computer control
collects the data from the AEBs, processes the
data and formats the data on a digital tape for
future analysis. The CCS is also capable of
controlling the majority of the AEB functions
via a command link. The AEB is configured to
sample sensor data and acquire position data
at three hour intervals automatically. The
present sensor configuration allows 6 primary
sensors with 10 bit resolution and 16 auxiliary
sensors with 5 bit resolution. The auxiliary
sensors are sampled only once per day. The
sensor data and position data are stored in a
digital memory which is transmitted via an H.F.
link once per day to the Central Control Station.
A unique dual memory concept is utilized
to prevent data loss due to propagation vagaries
and polar cap absorption events. The
position measurements are accomplished by an
on-board NAVSAT receiver.
INTRODUCTION
The NOM Data Buoy Office (NDBO) engineering
development activities include the development
of arctic data buoys in support of national and
international scientific experiments. As part
of these activities a program has recently been
successfully concluded to develop and test three
prototype arctic environmental buoys (AEB) to
provide the remote data requirements of a
scientific experiment designed by the kctic
- Ice gynamics Joint Eperiment (AIDJEX) Project
Office. The experiment is designed to investigate
the large scale response of sea ice to
changing environmental parameters. The AIDJEX
program as presently envisioned is the first of
a series of studies that will subsequently be
incorporated under a large E a r seriment
(POLEX). The objective of the AIDJEX experiment
is to reach, through coordinated field experiments
and theoretical analysis, a fundamental
understanding of the dynamic and thermodynamic
interaction between arctic sea ice and its environment
and to answer basic questions of the
mechanisms which cause large scale ice deformation
and the effect of ice deformation and
morphology on the heat balance.
The experimental design requires the establishment
of an array of drifting ice buoys in the
Arctic Ocean to measure atmospheric pressure and
temperature at the sea ice surface. An essential
requirement of the buoy design was to develop a
position determination capability, an order of
magnitude beyond the capability of polar orbiting
meteorology satellites with position fixing capability,
which would be operational during the
experiment .
The program phases included the following
elements: the study of the experimental design
for the AIDJEX experiment which involved the
array of Arctic Data Buoys (AEB) and the translation
of the system measurement requirements
into a system specification; the design and
development of prototype system hardware to meet
the measurement requirements and test objectives
of the AXDJEX experiment; fabrication of three
prototype AEB's and associated test set for test
and evaluation in the field prior to the main
experiment; and performance of laboratory and
field testing on the prototype system to verify
experimentally its ability to meet the measurement
requirements and test objectives of the
main experiment. The design, development and
fabrication program was performed by the Polar
Research Laboratory in Santa Barbara, California
under contract to NDBO.
DESIGN CONSIDERATIONS
The conceptual design of the Arctic Environmental
Buoy (AEB) System was formulated to meet
both the near term requirements of the Arctic Ice
Dynamics Joint Experiment (AIDJEX) and the general
need for gathering data on the Arctic ice
pack. The basic requirements were to sample a
number of sensors on a synoptic basis (i.e.,
every 3 hours starting at 0000 Zulu), provide an
accurate position for the system 8 times a day
and to transmit the data at least once per day.
In addition the AEB system was to have an unattcnded
life of 8-14 months. The range of the remote
buoy stations from the Central Station is expected
to be 250 to 500 Km during the life of the
experiment and therefore an H.F. link was selected.
Frequency selection and modulation methods
were chosen on the basis of computer analysis
and studies (1)(2)(3) performed at the Institute
of Telecommunication Sciences in Boulder, Colorado.
The structural design of the buoy hull and
antenna was heavily influenced by the unique
environmental conditions of the Arctic ice pack.
50 - IEEE OCEAN '75
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