Integration of Radar, Acoustic, and Night Vision Monitoring of Bats at Wind Power Projects

Integration of Radar, Acoustic and Night Vision

Monitoring of Bats at Wind Power Projects

Integration of Radar, Acoustic and Night Vision

Monitoring of Bats at Wind Power Projects

David E. StephensonNatural Resource Solutions Inc.

CanWEA 2006

David E. StephensonNatural Resource Solutions Inc.

CanWEA 2006

OverviewOverview

• Introduction• Challenges of Bat Monitoring• Overview of Approaches

– Acoustic Monitoring– Night Vision Monitoring– Radar Monitoring

• Lessons Learned

IntroductionIntroduction

• Increasing emphasis on bat studies for wind power projects

• Combination of uncertainties and high incidence of mortality at some sites

• Number of guidance documents/protocols being developed

• Wide range of approaches used to study bats

• Talk focuses on techniques used by NRSI at 10 wind power facilities in southern and central Ontario

Challenges of Bat MonitoringChallenges of Bat Monitoring

• Generally little local information about bats• Misconceptions about bats• Seasonal/spatial changes in species & behaviours• Bat activity and weather• Nocturnal activities

• Wide range of approaches being used, widespread

modification of devices

Acoustic MonitoringAcoustic Monitoring

• One of the most common techniques is use of ultrasonic detection devices

• Rely on detecting high frequency ‘calls’ & translating them into audible sounds

• Devices that are tuned to a specific frequency versus broadband devices that can record calls for subsequent analysis

Acoustic MonitoringAcoustic Monitoring

• Range of devices• Accurate species

identification from calls• Susceptible to interference

and distortion• Challenge of detecting

‘calls’ at turbine blade height

• Storage of recorded calls can be problematic (straight recording of 8hrs = 4GB, time expansion calls could yield >10,000 call files per night)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

1 2 3 4 5 6 7

Monitoring Station

Passes/hr

Hoary Bat

Red Bat

Little Brown Bat

Night Vision MonitoringNight Vision Monitoring

• Relies on low-light enhancing devices• Commercially available devices (Generation

2+) • Storage medium challenges (full 8 hr night

approx. 60GB)• Limited field of vision• Ability to detect bats varies

Night Vision MonitoringNight Vision Monitoring

Generation 2+(with Infrared)Generation 2+

Radar MonitoringRadar Monitoring

Nexrad Radar• Effective range for bird/bat monitoring less than full

range• Use both base reflectivity as well as base velocity• Less effective for local investigations, low density

flights, low altitude investigations• Various anomalies can occur

Radar MonitoringRadar Monitoring

Marine Surveillance Radar

• Devices and methods vary, some off-the-shelf, others modified (esp. antennae or array)

• Use in poor weather can be variable• Clutter is a challenge • Use of CTM allows for 3D flight

trajectory analysis (direction, altitude, speed & changes)

• Remember safety – working with radar is like using a microwave with the door open!

0

2

4

6

8

10

12North

1020

3040

50

60

70

80

East

100

110

120

130

140150

160170

South190

200210

220

230

240

250

260

West

280

290

300

310

320330

340350

Radar MonitoringRadar Monitoring

Marine Surveillance Radar• Target analysis is complex (e.g.

10,000 targets per night is not uncommon)

• Difficult to tell bats from birds• Range of device can be >100km

but ability to discriminate targets is affected

• Passes/hour versus passes/m3/hour

Bearing to Bat Target

0

2

4

6

8

10North

1020

3040

50

60

70

80

East

100

110

120

130

140150

160170

South190

200210

220

230

240

250

260

West

280

290

300

310

320330

340350

Flight Direction of Bat Targets

Radar MonitoringRadar Monitoring

Marine Surveillance Radar• Bat activity density (passes/m3/hour)

0

0.0005

0.001

0.0015

0.002

0.0025

<40 40 -60

60 -80

80 -100

100 -120

120 -140

140 -160

160 -180

180 -200

>200

Altitude (m agl)

Passes/m3/hr

Station 1

Station 2

Station 3

Staton 4

Station 5

Lessons LearnedLessons Learned

• Improved results with integrated use of devices/techniques• Time expansion acoustic ‘call’ identification• 3 dimensional radar flight analysis• Bat monitoring is very data-heavy (tera-bytes of data)• Data collection & analysis are time consuming • Keep the biologist in the process

Booth # 624www.nrsi.on.c

a

Booth # 624www.nrsi.on.c

a

Who isSecuring

Your Project?

Who isSecuring

Your Project?