Spectrum monitoring, direction finding and microwave link measurements from the air
LS OBSERVER Airborne Monitoring Unit (AMU)
The LS OBSERVER Airborne Monitoring Unit (AMU) enables spectrum monitoring operations from the air. The key benefits of measuring with drone-based systems are:
- Fly above obstacles that absorb or weaken radio signals
- Receive signals with a better signal to noise ratio (SNR)
- Detect more emissions than from ground level especially in urban areas or hilly terrain
- Capture a larger area for monitoring in comparison to ground-based stations
- Capture the signal inside the fresnelzone
- Cost-effective and timesaving (no lifting platforms and no climbing on buildings required)
- Measurements in inaccessible areas
Direct line of sight to emitter
Fly above obstacles/metal structures which reduce DF accuracy
Achieve a better direction finding and localization accuracy in urban areas or hilly terrain
The airborne monitoring unit is a specially designed drone that can carry various types of RF payloads. The design of the drone and payload includes shielding of strong external signals from the internal electronics, so it can fly close to transmitters or inside microwave links. Further the design includes technologies to reduce self-interference from drone motors and electronics to the radio receiver to a minimum.
The RF payload includes beside an antenna, a radio receiver, embedded processor, a modem for network communication and a large, embedded storage. Different types of antennas can be attached to a specific payload for different use cases e.g. for direction finding a directional antenna can be attached while for standard spectrum monitoring an omni antenna is used. For SHF/EHF applications, such as microwave link measurements, the standard payload for spectrum monitoring can be exchanged by a special payload with a different type of receiver that can reach higher frequency e.g. up to 44 GHz. The standard portfolio includes a 6 GHz and 32 GHz receiver. For receiver requirements that go beyond the standard specifications, customized solutions up to 110 GHz are possible.
The AMU can be operated on battery for flexible short operations. In situations where longer measurements are needed the AMU is available as a tethered version enabling powering and data transfer via cable. By this the AMU can stay up in the air for multiple hours. A typical set up for this is that the AMU is stored and launched from a pick-up truck that can supply power to the drone. With the tethered version not only power is supplied via cable but also the data connection. By this a stable and fast data connection to the ground can be guaranteed.
CMS offers a comprehensive suite of features for various measurement tasks and analysis. Whether you want to run ITU compliant signal measurements, direction finding and geolocation or automated measurement tasks like automatic violation detection (AVD) with correlation to the spectrum management database, CMS combines it all in one unique software suite.
ColMP software (based on ArduPilot™) enable pre-planning of flights with waypoints and gives important information to the drone pilot. The AMU can fly precisely and automated along the defined waypoints. For applications where highest precision is required a differential GNSS system can be used together with the AMU.
The CMS software cannot only control a single AMU but is used to manage a complete LS OBSERVER network. From the operation center an operator can for example combine the direction-finding results from the AMU and a fixed station together to triangulate an emission remotely.
The LS OBSERVER CMS further builds the bridge between Spectrum Management and Monitoring. By combining it with mySPECTRA the theory is compared with the real measured spectrum environment enabling the user to detect license violations, whitespaces or overloads and further anomalies. Valuable information from monitoring is then fed back to spectrum management to support the assignment process.