Keysight RF Sensors

Several of the AERPAW fixed nodes will include Keysight N6841A RF Sensors. These sensors have a wideband RF receiver with 20 MHz to 6 GHz frequency range and a maximum real-time bandwidth of 20 MHz. They are embedded within an environmentally rugged IP67-rated weatherproof enclosure, and they have an integrated GPS for sensor location and time-synchronous applications. Their signal LOOKback memory of 4.8 secs at 20 MHz BW makes it possible for reliably detection, processing, and location of short-duration signals or interference. Some use cases for N6841A RF sensors include automated spectrum monitoring, signal intercept, collection and classification using N6820ES Signal Surveyor 4D software, signal capture and analysis using 89601B Vector Signal Analyzer software, and emitter location and RF geo-analytics using N6854A Geolocation Server software.

AERPAW Phase-1 GA will not include any Keysight RF sensor experiments, which are intended to be integrated to Phase-2 GA. On the other hand, the AERPAW team has conducted several initial experiments with the Keysight RF sensors, and several examples are provided in the following sub-pages.

Key Features of Keysight RF Sensors

• Frequency Range: 20 MHz - 6 GHz

• Digital Bandwidth: Adjustable up to 20MHz

• GPS Location: Enabled

• RF input ports: 2 type-N ports

• Durability: Waterproof body

• Broadband Antenna: Omni-directional

• Power: Less than 30W

• Voltage: 15-24V DC

Data Sheet for N6841A

Software to Interface with Keysight RF Sensors

1. Geolocation Software: Keysight N6854A RF Geolocation Software estimates the position of an RF transmitter using different unique localization techniques.

2. Surveyor 4D: This tool can be used to detect different types of RF signals within a certain band of frequency. You can expand the view to observe a particular signal. In the energy detection mode, you can get a lot of information about a signal (like bandwidth, center frequency, amplitude, etc.). Suppose a drone is flying in the air, you can collect continuous data using the Surveyor 4D tool. You can set an alarm if the energy of the received signal is above a certain threshold. This software is explained in more details in Signal Surveyor 4D

3. Sensor Planning and Optimization Tool (SPOT)

The name of the tool is quite self-explanatory. Before collecting any data, one needs to plan where the sensors to be placed for the optimal output. The received signal power or TDOA also depends on what kind of area is used (ex. - dense urban, rural, etc). You need to extract the map of your interest from http://www.openstreetmap.org and then place the sensors randomly (you can also get the latitude and longitude of the sensors - refer to the SPOT manual for details). You can run the simulation to get the followings:

• The range of the probability of detecting an RF signal

• Sensor density estimation (number of sensors should be used)

• Relative signal strength plot

• TDOA contour lines to get an idea of the effectiveness of sensor placements accurately

• Rendering an estimated position (EP) in the area of interest

4. Sensor Access Library (SAL)

User can build their own application to post process the data collected by RF sensors. SAL explains all the required modules and their scripts which can be used to build an user application.

5. Vector Signal Analyzer (VSA) Tool

Once the data is collected using the Surveyor 4D and loaded into the database, this software tool helps you to visually analyze the signal. One can also demodulate the signal and re-transmit the same signal. More details can be found in VSA Software

Notes:

• Use the official website of Keysight to download any software: https://support.keysight.com/KeysightdCX/s/?language=en_US -- type the software name in the search bar which will bring technical overviews and user manuals.

• While installing the SMT software, you may get “port conflict” error. SMT uses only the port 8080 and it does not work in any other port. If you get this error, type “cmd” in the windows search bar. In the cmd window type “netstat -ano”, thus you will get the information which PID number(or application) is using which port. Find out 8080 port and note down the corresponding PID number. Now, go to the task manager, go to “services” tab, sort the services with PID number. Find the PID number you have noted. Stop the service and try reinstalling SMT.