Bat Monitoring System BATmode 2S/2S+

Record bat calls with up to four microphones simultaneously


The BATmode 2S/2S+ system is a modular bat monitoring system specially designed for the use on wind turbines. It consists of a central detector unit, the BATmode 2S or 2S+, up to four microphones including the associated UltraSoundGate analog-to-digital converters from Avisoft Bioacoustics as well as an antenna. Depending on your measurement requirements, you can choose between the two different versions 2S and 2S+, the number of required microphone channels as well as different microphone versions. Thus, the system can be optimally adapted to your measurement requirements and the measurement task can be carried out as cost-effectively as possible. The modular use of the UtraSoundGate analog-to-digital converter also allows to use this cost-intensive hardware module on other measuring systems or for data evaluation on desktop computers. If you want to start with just one microphone channel, you can upgrade your BATmode 2S/S2+ system in future with additional measurement channels to expand your BATmode for new measurement requirements. Thus, the system grows with your measurement tasks and the initial and subsequent investments are correspondingly low. Due to the large internal memory of 256 or 512GB it is possible to operate a BATmode 2S/2S+ system for a complete season without changing memory devices. To ensure the highest possible data security, the data can be copied daily to external USB 3.0 drives for backup. Remote access to the system is possible via LTE, Ethernet and WIFI (only BATmode 2S+). The system is controlled via the intuitive BATcontrol software. In addition to various options of remote control via SMS, e-mail, myBAT cloud, smartphone app as well as Remote Desktop, it also offers several data analysis tools. By this, you can evaluate the quality of the recorded data at a glance. Due to the DIN rail mounting system of the BATbox 2S, you can install the system in conformity to legal guidelines and without effort in the nacelle of wind turbines.

With all the named features the BATmode 2S/2S+ system is the perfect device for long-term monitorings of bat activity on wind turbines. Since it utilizes the UltraSoundGate hardware of Avisoft Bioacoustics specified in the RENEBAT-Projects, it is fully compatible with ProBat, the software tool for calculating turbine-specific curtailment algorithms.


BATmode 2S/2S+

The BATmode 2S/2S+ is the central unit of the bat detection system for wind turbines. Its 7th generation Intel® i3 CPU and the Windows® 10 operating system provide an enormous flexibility and intuitive operation.
For a calibrated bat call detection and a reliable separation of call sequences from noise the proven UltraSoundGate of Avisoft Bioacoustics is utilized. With this single-channel analog-digital-converter high-quality real time recordings of bat calls with a resolution of 16 bit and a sampling frequency of at most 300 kHz are achievable. In combination with a 256 GB (2S) or 512 GB (2S+) SSD, respectively, the automated real time monitoring over a complete year is possible without changing memory devices even once. To guarantee for data integrity the system can daily backup recorded data on external drives.
For an efficient bat monitoring in the nacelle of wind turbines a high availability and accessability of the BATmode 2S/2S+ is substantial. Therefore, we implemented various ways to access the system. On the one hand, you can use tethered interfaces of the BATmode 2S/2S+ (USB, HDMI, LAN) to connect it on-site or control it remotely via ethernet connection. On the other hand, you can also apply wireless interfaces. A WIFI connection to the tower base, for instance, allows for remote desktop control and dependent on turbine's height even broadband transmission of the recorded data (exclusively BATmode 2S+). Furthermore, if mobile cellular network is available on-site, remote desktop control of the system is also possible via the integrated cellular 4G LTE modem. In case of low transfer rates of cellular network connection, you can also transmit major control commands via SMS.
The BATmode 2S/2S+ needs a conventional power supply of 100-240V 50/60Hz AC. In case of power failure the bat monitoring will be interrupted. However, on returning power the system will restart automatically and continue a started bat monitoring.
In addition to acoustical data, the 2S+ version of the BATmode-System is also capable to acquire environmental conditions like temperature and precipitation rate. A corresponding temperature sensor is integrated in the antenna disc and is part of the scope of delivery. To acquire precipitation rates an optical precipitation sensor can be purchased separately.


  • Intel® Core i3-7100U
  • Intel® HD Graphics 620
  • 8 GB RAM
  • 256 GB SSD (2S) / 512 GB SSD (2S+)
  • WIFI Intel® Dual Band-Wireless-AC 8265 (nur 2S+)
  • Cellular modem Huawei ME909s-120 4G LTE
  • 2x USB 2.0, 2x USB 3.0, 2x HDMI, Gigabit LAN
  • Connector for heating unit (Cinch)
  • Connector for cellular antenna (RP-SMA)
  • Connector for WIFI antenna (RP-SMA) (exclusively 2S+)
  • Connectors for temperature and precipitation sensor (Mini-XLR) (exclusively 2S+)
  • Power supply: 100-240V 50/60Hz AC
  • Power consumption: ca. 20 W


  • Windows® 10 Professional (OEM)
  • Avisoft-RECORDER Software
  • BATcontrol-Software

Avisoft UltraSoundGate 116Hnbm

The external single-channel UltraSoundGate 116Hnbm of our cooperation partner Avisoft Bioacoustics allows for a calibrated detection of bat call sequences. With a resolution of 16 bit and a sampling frequency of at most 300 kHz high-quality real time recordings of bat calls are achievable. To suppress noise recordings and detect bat calls reliably, the UltraSoundGate features a realtime filter. In comparance to competing detectors the filter is not only frequency based but on the contrary analyzes the temporal signal. By this, specific characteristics of bat calls could be recognized and calls are recorded reliably.


  • Single-channel Delta-Sigma ADC with integrated anti-aliasing filter
  • Resolution: 16 bit
  • Sampling rate: up to 300 kHz
  • Frequency response: 1 - 135 kHz
  • Input sensitivity: -9 dBV = -7 dBu = 0,35 Vrms
  • Input impedance: 50 kOhm
  • Interface: USB 2.0


Depending on your application, the bat monitoring system BATmode 2S/2S+ can be used with different microphones, all of which are specially designed for the use on wind turbines. The microphone discs GM50 and GM90 allow the detection of bat activity at the height of the rotor hub and are installed downward looking in the bottom of the nacelle of the wind turbine. In addition to the Electret ultrasonic microphone from Knowles, both microphone discs are additionally equipped with a test signal speaker and a microphone heater. However, while the microphone disc GM50 requires only a mounting hole diameter of 55mm, the larger microphone disc GM90 requires a diameter of 100mm. In contrast to the GM50, which allows only qualitative bat activity monitoring, the GM90 is fully compatible with the BMU guidelines of the RENEBAT-Projects and the software tool ProBat, which can calculate corresponding operating algorithms from the acoustic data of the monitoring at nacelle height and wind data.
If the bat activity has to be recorded qualitatively at the level of the lower rotor tips by means of a so-called tower monitoring, the BATmode 2S/2S+ system can also be equipped with one of the two tower microphones TM10 or TM20. The TM10 requires only a wall-mounting hole with a diameter of 14mm. But in contrast to the TM20, which needs a diameter of 22mm, the TM10 integrates no test signal speaker.
All microphones are equipped with a preamplifier, which allows a very low noise level of the microphone signals and thus enables cable lengths of 150 m and more between the bat monitoring system BATmode 2S/2S+ and the microphone disc. To protect against weather and environmental influences, all electronic components are encapsulated splash-proof.


  • Ultrasound microphone Knowles FG-23629-P16
  • Preamplifier
  • Microphone heating unit (2,5 W)
  • Test signal speaker (not TM10)
  • Made of aluminium/stainless steel


The remote accessability of the BATmode 2S/2S+ highly depends on the reception of WIFI and cellular network signals.

The BATmode 2S system, which is equipped with a 4G LTE cellular modem, is supplied with a magnetic base antenna. This antenna can be attached to any ferro-magnetic surface and has a 3m connection cable.

In addition to the cellular 4G LTE modem, the BATmode 2S+ is equipped with a WIFI adapter. By applying the so-called antenna disc with its integrated directional WIFI antenna a broadband WIFI connection to the tower base can be established and allows for remote access to the system even if mobile network reception at the site is poor. The splash-proof antenna disc, which also contains the cellular antenna as well as a temperature sensor, is installed next to the microphone disc in the bottom of the nacelle. With its 100mm the required mounting hole diameter equals the one of the microphone disc. Consequently, tool requirements for the installation are minimized.

Magnetic base antenna (BATmode 2S)

  • Cellular antenna

Antenna disc (BATmode 2S+)

  • Directional WIFI antenna
  • Cellular LTE antenna
  • Temperature sensor
  • Made of polyvinylchloride
  • Diameter of mounting hole: 100 mm


The software BATcontrol is used to control and parametrize the BATmode 2S/2S+ System as well as the recording software RECORDER of Avisoft Bioacoustics. Consequently, we are able to combine the proven advantages of RECORDER (outstanding bat call recognition filter, calibrated filter trigger, full spectrum recordings in real time, multi-channel capabilities and much more) with various features for remote control and data evaluation specifically adapted to the needs of bat monitorings at the nacelle of wind power plants. By applying a predefined set of parameters, which complies to legal guidelines, the operation of the system could be simplified and you only have to adjust site-individual settings.
To minimize costs for on-site maintenance and keep an eye on the status of the system BATcontrol is able to send you the most important parameters either via SMS, mail or our cloud service myBAT on your phone or desktop pc. Furthermore, myBAT also gives you the opportunity to evaluate information about recorded data in real time and export them to external tools. If you want to change some major settings, you can control BATcontrol via myBAT or even SMS commands if mobile network reception is poor. But you cannot only change major settings. If a sufficient mobile network connection is available at the site, you can establish a full remote desktop connection to the system. And if reception is insufficient, you can simply use the WIFI hotspot provided by BATcontrol to access the system from the tower base (available only with BATmode 2S+).
Since it is often difficult to assess the quality of recorded data and exclude noise recordings BATcontrol provides graphic evaluation tools and supports you to evaluate recorded data on the fly. So you are able to intervene and avoid unusable data in advance. Furthermore, data compliance to legal guidelines can be guaranteed by daily monitoring of the microphone sensitivity with the integrated test signal speaker and the appendant graphic assessment tool.
In addition to acoustical data, BATcontrol also enables the acquisition and evaluation of weather conditions like temperature and precipitation rate (available only with BATmode 2S+).


  • Controls Avisoft-RECORDER software
  • Microphone calibration
  • Daily measurement of microphone sensitivity
  • Status information, remote control and data evaluation via myBAT
  • Status messages via SMS or mail
  • Remote control via SMS
  • Acquisition of temperature and precipitation rate (exclusively BATmode 2S+)
  • Data evaluation tools
  • Daily backup
  • WIFI hotspot (exclusively BATmode 2S+)

Head-to-head comparison of BATmode 2S and BATmode 2S+

  BATmode 2S BATmode 2S+
Operating system Windows® 10 Windows® 10
Processor Intel® Core i3-7100U Intel® Core i3-7100U
Hard disc drive 256GB SSD 512GB SSD
Cellular modem Huawei ME909s-120 4G LTE Huawei ME909s-120 4G LTE
WIFI Intel® Dual Band-Wireless-AC 8265
Interfaces 2x USB 2.0 for UltraSoundGates, 2x USB 3.0, Gigabit LAN, 2x HDMI, RP-SMA for cellular antenna, chinch heating connector 2x USB 2.0 for UltraSoundGates, 2x USB 3.0, Gigabit LAN, 2x HDMI, RP-SMA for cellular and WIFI antenna, chinch heating connector, 2x mini-XLR for temperature- and precipitation sensor
Measurement channels 1-4 1-4
Analog digital converter up to four Avisoft single-channel UltraSoundGates 116Hnbm or one Avisoft four-channel UltraSoundGate 416Hnbm up to four Avisoft single-channel UltraSoundGates 116Hnbm or one Avisoft four-channel UltraSoundGate 416Hnbm
Resolution 16 bit 16 bit
Sampling frequency 300 kHz 300 kHz
Microphone Knowles FG Knowles FG
Microphone preamplifier
Microphone heating unit
Testsignal speaker depends on microphone depends on microphone
Control software BATcontrol BATcontrol
Recording software Avisoft-RECORDER Avisoft-RECORDER
WIFI remote access
LAN remote access
Cellular remote access
Antenna Cellular antenna with magnetic base Antenna disc with temperature sensor
Status Mail / SMS
SMS remote control
mybat Cloudservice
Daily backup
Temperature sensor
Precipitation sensor optionally