N6820HFPE Wideband VLF-HF Receiver Driver

Introduction

Keysight’s N6820HFPE is a licensed software feature that enables Surveyor 4D software to connect to the N6831A, a high-performance, real-time, full-band VLF-HF receiver.  It includes two programs required for operation:

• Surveyor 4D driver installed on a Windows© host PC, and

• An N6831A measurement server application installed on a LINUX server that handles both the command and control and high-speed data from the N6831A

The N6820HFPE software feature enables the N6831A receiver to communicate with the N6820ES Surveyor 4D software on a VITA-49.2 streaming interface, a widely adopted industry standard for streaming data, command, and control format.

This platform feature requires Surveyor 4D version E.4.5 or later and is intended to provide users running old versions of the 35688E or N6820E software on VXI-based hardware a path to update their software license and use it with the new N6831A HF monitoring hardware.

N6831A VLF-HF wideband receiver

The N6831A receiver will process the full VLF-HF band (9 kHz to 32 MHz) with 16-bit resolution making use of a 1-million-point FFT for remarkable speed and resolution.  Several pre-selection filters, step attenuators, and gain stages optimize the sensitivity and integrity of the received signal data.  Users can manually control the filters based on the environmental challenges they face and monitor their band of interest.  Additionally, the receiver has 128 DDC channels providing a robust narrowband signal processing capability used to classify signal candidates, make recordings, tip, and source data to other systems.  The receiver is housed in a compact 1 rack unit package, operates on DC power, and includes a GPS receiver (L1) that provides frequency and time references for accurate time stamping to support precision time-dependent applications. 

LINUX server requirements

The n6831aMeasServer is a standalone Linux service that:

• Configures the Keysight N6831A VLF-HF Receiver 

• Controls and orchestrates spectral sweep, 128 time-series IQ data streams, and audio streams

• Demodulates audio

• Removes transient/invalid data during state/configuration changes on data streams

• Offers locks on resources to ensure exclusive access

• Logs system warnings/errors and alarm states

The n6831aMeasServer listens on a TCP/IP socket for connections from the Keysight VRA (VITA-49 Radio Access) client library/API, both services can be obtained from:

https://www.keysight.com/find/n6831a

N6820HFPE installation

The N6820HFPE feature is installed using the N6831A download that is found at www.keysight.com/find/N6820ES. The installer places the N6820ES-related files, the VITA-49 Radio Access (VRA), and the n6831aMeasServer software onto the host PC.

After installation, you will find new folders that contain pre-configured applications, USD detectors, and other examples to use the N6831A receiver with Surveyor 4D software:     

• C:/E3238s/Apps/VRT/N6831A includes shortcuts to standard Surveyor 4D configurations using the HF receiver and provides examples of the Surveyor 4D software features:

   o Narrowband Recorder (NBR) folder (highlights streaming narrowband recorder feature)

   o No Hardware folder (highlights the use of Surveyor 4D’s simulated spectrum mode)

   o N6831A USD (highlights the use of the Universal Signal Detector for isolation of specific signals).  The sampling rate of the N6831A provides bin spacing compatible with USD detectors made with the Agilent N6830A HF/IF ADC VXI module.

• C:/E3238s/detectors/VRT/N6831A includes USD detectors created for signals found in the HF band.  For more feature information, refer to the N6820USDE technical overview. 

• C:/Program Files (x86)/Keysight/N6831A/linux is where the N6831A measurement server application (n6831aMeasServer.rpm) and associated read me text is installed and is needed to setup the LINUX server

• C:/Program Files (x86)/Keysight/libvra is where the VITA-49 Radio Access programming interface files are installed.