Fresh from the boat: Great Duck Island habitat monitoring

Robert Szewczyk

Joe Polastre

Alan Mainwaring

June 18, 2003

Outline

• Application overview

• System & node evolution

• Status & preliminary evaluations

• Conclusions

Great Duck Island Petrel monitoring

• Goal: build ecological models for breeding preferences of Leach’s Storm Petrel

– Burrow (nest) occupancy during incubation– Differences in the micro-climates of active

vs. inactive burrows – Environmental conditions during 7 month

breeding season

• Inconspicuous Operation– Reduce the “observer effect”

• Sensor Network– Lifetime, size, quantity requirements– Environmental conditions

• Data– As much as possible in the power budget

• Predictable operation– Confidence in collected readings

• Unattended, off-the-grid operation

System structure

Transit Network

Basestation

Gateway

Sensor Patch

Patch Network

Base-Remote Link

Data Service

Internet

Client Data Browsingand Processing

Sensor Node

System implementation

Mica2-EPRB#2

IBM laptop #1DB

Web power strip

Axis 2130 PTZ South

Wireless bridge

4-port VPN router and

16-port Ethernet switch

Power over LAN midspan DB

IBM laptop #2

Mica2-EPRB#2

WWW power strip

Southern WAP

Satellite router

Sensor Patch

916 MHz

Power over LAN Midspan

IR Burrow Camera #1

IR Burrow Camera #2

IR Burrow Camera #3

)IR Burrow Camera #4

IR Burrow Camera #5

IR Burrow Camera #6

IR Burrow Camera #7

IR Burrow Camera #8

Axis 2401 Video Server

12VDC, 0.9Anetwork

Burrow Camera Configuration

Northern WAPEthernet switchWireless bridge

12V PoLActive Splitter

110VAC service

Node architecture advances

• Problems observed in previous deployment– Size – motes were too large to fit in many burrows

– Packaging – did not provide adequate protection for electronics or proper conditions for sensors

– Reliability – last retreat talk; high rate of node loss, lack of scientifically meaningful environmental data

– Power consumption – boost converter a minimal return at a high price

• New generation of motes to address most of these concerns

– Platform based on mica2dot

– Primarily calibrated, digital sensors

– Multiple application-specific packaging, power, and sensing options

Mote evolution

Miniature weather station

• Sensor suite– Sensirion humidity + temperature

sensor

– Intersema pressure + temperature sensor

– TAOS total solar radiation sensor

– Hamamatsu PAR sensor

– Radiation sensors measure both direct and diffuse radiation

• Power supply– SAFT LiS02 battery, ~1 Ah @

2.8V

• Packaging– HDPE tube with coated sensor

boards on both ends of the tube

– Additional PVC skirt to provide extra shade and protection against the rain

Burrow occupancy detector

• Sensor suite– Sensirion humidity +

temperature sensor

– Melexis passive IR sensor + conditioning circuitry

• Power supply– GreatBatch lithium thionyl

chloride 1 Ah battery

– Maxim 5V boost converter for Melexis circuitry

• Packaging– Sealed HDPE tube, emphasis

on small size

Software architecture advances

• Bi-directional communication with low-power listenting

– .1% duty cycle

• Parameter adjustment and query– Sample rate changes, sensor status queries

• Improved power management scheme– Fine granularity through StdControl interface

– 20 uA sleep mode

• Multihop deployment planned for July

• What it isn’t: GSK– Emphasis on simplicity and reliability, rather than generality

– Compatible with most GSK server-side interfaces

Application status

• Sensor network– 26 burrow motes deployed

– 12 weather station motes deployed (+2 for monitoring the insides of the base station case)

» Another 14 are awaiting deployment within days

• Redundant database setup online– 2 base stations logging packets to 2 database servers

– Replication to Berkeley

• Verification infrastructure– Overview cameras in place

– Burrow cameras temporarily offline, wireless bridge problem

– Video logging still needs to be synchronized with the mote data service

Burrow motes: deployment

5.6027 5.6028 5.6029 5.603 5.6031 5.6032 5.6033 5.6034

x 105

4.8881

4.8881

4.8881

4.8881

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882x 10

6

206

225

219230

208

229

201

213

228207

227

226

212212

220

202

203

222

221

217

209210

204

216

215214

Burrow mote locations

X coordinate (UTM)

Y c

oord

inat

e (U

TM

)

Repeater

Burrow motes: link performance

5.6027 5.6028 5.6029 5.603 5.6031 5.6032 5.6033 5.6034

x 105

4.8881

4.8881

4.8881

4.8881

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882x 10

6

34

41

5257

61

66

69

81

8585

85

85

8686

86

87

87

88

90

90

9496

96

96

9797

X coordinate (UTM)

Y c

oord

inat

e (U

TM

)

Percentage of packets received from burrow motes

Repeater

Burrow motes: sample data

06/15 06/16 06/16 06/17 06/17 06/18 06/180

5

10

15

20

25

30

35

40

45

50Temperature readings from burrow motes

Time

Tem

pera

ture

(oC

)209210221202

Burrow motes: sample data

06/15 06/16 06/16 06/17 06/17 06/18 06/180

20

40

60

80

100

120Humidity readings from burrow motes

Time

Rel

ativ

e H

umid

ity (

%)

209210221202

Burrow motes: sample data

06/15 06/16 06/16 06/17 06/17 06/18 06/18-20

-15

-10

-5

0

5

10

15

20Passive IR readings from burrow motes

Time

IR r

adia

tion

over

am

bien

t te

mpe

ratu

re209210221202

Weather stations: deployment

5.6027 5.6028 5.6029 5.603 5.6031 5.6032 5.6033 5.6034

x 105

4.8881

4.8881

4.8881

4.8881

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882x 10

6

X coordinate (UTM)

Y c

oord

inat

e (U

TM

)

Weather station locations

127

122

126

129

124121 128

125

123

108

102

101

103Repeater

Weather stations: link performance

5.6027 5.6028 5.6029 5.603 5.6031 5.6032 5.6033 5.6034

x 105

4.8881

4.8881

4.8881

4.8881

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882

4.8882x 10

6

X coordinate (UTM)

Y c

oord

inat

e (U

TM

)

Percentage of packets received from the weather station

91

87

90

90

87

86

74

82

90

88 46

91

37

Repeater

Weather stations: sample data

06/08 06/10 06/12 06/14 06/16 06/18 06/200

20

40

60

80

100

120Humidity readings from weather stations

Time

Rel

ativ

e H

umid

ity (

%)

101102103105

Weather stations: sample data

06/08 06/10 06/12 06/14 06/16 06/18 06/200

5

10

15

20

25

30

35

40

45

50Temperature readings from weather stations

Time

Tem

pera

ture

(oC

)101102103105

Weather stations: sample data

06/08 06/10 06/12 06/14 06/16 06/18 06/200

0.5

1

1.5

2

2.5

3

3.5

4x 10

10 PAR readings from weather stations

Time

Pho

to d

iode

cur

rent

(uA

)101102103105

Weather stations: sample data

06/08 06/10 06/12 06/14 06/16 06/18 06/200

0.5

1

1.5

2

2.5

3

3.5

4Voltage readings from weather stations

Time

Vol

tage

(V

)101102103105

Packaging evaluation

• We observed what happens to motes when packaging fails– Battery venting, H2SO3 corroding the entire mote

– Need to assemble the package correctly – we failed to create proper indication os a good seal

– Majority of packages survived severe weather!

• Still awaiting evaluation whether the package creates an environment suitable for sensing

– Convective heating, etc.

Conclusions

• Next generation of environmental sensor networks

– Smaller, better, more robust

– Application specific sensor suites vs. kitchen sink

• Infrastructure matters– Redundancy at every level

– Remote administration and rebooting

– Data verification is key!

• More analysis to come– Biology studies based on the system

– Compare notes with James Reserve system