The microphone is intended for audio surveillance on large remote distances.
Distinctive Features
- Acoustic surveillance/observation up to 300m
- Verbal communication can be retrieved from materials such as metallic elements, cloths, paper and plastic.
- Can operate from any angle
- Easy to use
- Fast and simple start to work and target aiming
- The unit is safe for the eyes and totally stealth
- Noise robust, no interference from surrounding noise
- Requires the minimum vibrating of surfaces to allow surveillance via windows, f.e. in vehicles, rooms, etc.
Highlights
- Operates via window/small openings
- No physical entering needed for installation
- Can operate with any target surface
- Highest level of speech intelligibility
- Requires just 12VDC for operation
Operation scenario
The unit provides a range of benefits for those in the field who need to perform surveillance. The device uses the unique interferometric laser technology, which makes it a top choice for this type of work. It features an unseen infrared laser along with advanced DSP technologies. This allows for great speech detection and speech intelligibility even when the operating in noisy environments.
This device has the ability to detect vibrations caused by speech at various angles and on many surfaces. It does not matter if the targets are inside the building (office, apartment, etc) or outside. The backscatter laser light frequency shift makes it possible for the speech to be extracted. This makes the technology fully robust to various surfaces and laser intensity.
The unit has a fantastic operating range with minimum laser power, providing high performance surveillance, while still being safe. The device also happens to be quite easy to use.
Application
The unit is used to perform surveillance and record speech of a person who might be up to 300m away, in a vehicle, building, or elsewhere. The microphone picks up on surface vibrations, and it has the power to do all of this independent from the target optical conditions.
The laser is unseen by human eyes or common cameras. This allows users to target those in closed rooms through windows. During operation the system eliminates ambient interferences, noises.
How It Works
The sensor can collect the vibrations in various surfaces, as mentioned. It can detect speech, and the best sensitivity occurs when objects are thin, soft, or lightweight. Some of the targets that could be used include papers, leaves on a plant indoors, pictures hanging on a wall, seat cushions, window panes, and clothing. The beam detects vibrations, turns them into an electrical signal and then amplifies them and creates an audible output.
The vibrations, caused by a speaker, cause a backscatter laser light frequency (Doppler) shift. This shift is then extracted from the laser light. After that, the signal will pass through decoding and convertion to standard audio signal.
The System
It features two components: the infrared laser sensor and the monitor unit.
Infrared Laser Sensor
The device includes a laser source in the sensor, which meets eye safe laser Class 1 to prevent eye injuries, a precision interferometer, an inline and parallax-free color camera. It can be used to target and transmit, as well as receive long range optics. Manual fine adjustment is available for the laser focus for targets between 15m and 300m away.
Monitoring Unit
The processing unit is responsible for decoding interferometer signals to audio compatible signal paths. An analogue/digital/S/PDIF signals available as phone output and as a line jack to connect common audio recording and filtering units.
The sound level protection is achieved by using headset. The device has three sensitivity levels, which can be used as a means to optimize signal quality. Frequency bandwidth can be limited by special filters for obtaining good quality speech intelligibility. The unit features an inbuilt camera. Also an audio-video signal is available at a special headset connector. This allows operation of the supplied video glasses.
Target aiming, Adjusting and Focusing
Fast setup and target aiming is essential. Fortunately, the unit features all of the accessories needed, and it is all in a simple to set up and use system. It is possible to install the infrared laser sensor on a tripod and aim the laser accurately. The above mentioned features can help users to get their system set up quickly and effectively.
Visual Signal
The in-built video camera with the laser delivers a color image of the target zone with a central scale grid that matching with the laser. When the image in the glasses is in focus, it means the laser is in focus. You can adjust the focus to get it just right by using the focus ring on the lens. In cases where the light levels happen to be low, it is possible to use a mechanical interface on the sensor to adapt to a night vision scope.
Audio Signal:
After localization and focus of the target are acquired, the signal quality can be optimized. Scan for the best vibrating surface in the target zone. You can use the glasses or headphones, to help you adjust and perfect the audio signal.
When you utilize both the audio and the visual feedback at the same time, you will find that it allows you to find the targets faster and more effectively, and to get everything into proper focus. Overall, this tends to be a very easy system to utilize.