The SRS-3000 is a frequency-agile, lightweight HF VHF UHF receiver designed for limited space and high-mobility application for see, ground and air environment. Its compact size, broad tuning range and high-level remote control functionality make it ideal for multitude of system application, including commercial frequency management and military SIGINT COMINT EW missions. The receiver couples high scan speed, high frequency and time resolution, high dynamic range, and excellent selectivity to provide superior performance over many much other receivers. It achieves an outstanding in-band input third-order intercept point of +6 dBm, while maintaining a typical noise figure of less than 10 dB. The equipment can be used for high-speed spectrum management, search and intercept missions as a stand alone receiver or as a building block of high-grade multifunctional integrated SIGINT COMINT EW systems.

Digital receiver concept

Our digital receiver concept based on the Software Defined (SDR) technology, which means to digitize the data as earlier in the signal path as possible and do all of the functionality in digital domain. Before the analog to digital conversion the required analog signal processing contains band limiting and pre-selection, variable amplification and frequency conversion in higher VHF/UHF bands. After the digitization burst memory (FIFO) or digital down-converter (DDC) is used depending on the application which could be a wide-band scanning or narrow-band monitoring reception. Programmable logic (FPGA) is used for on-board data processing and routing before the data is passed to digital signal processing (DSP) algorithm. The whole receiver is handled trough graphical user interface (GUI) which is running on the platform computer. External connections are provided by the platform computer for local and remote control.

High-tech hardware implementation

We use the latest state of the art analog processing and digital conversion technology available in the market to provide high-dynamic range, wide-bandwidth front-ends and digitizers for our receivers with 14bit resolution and 80MHz sampling rate. All of our digital signal paths are designed for 16bit sample handling. The front-end of the receiver transform the interested frequency sub-band to the IF with maximum bandwidth, which is equal with real-time instantaneous bandwidth of the receiver. This full-band signal can be used for fast scanning, parallel processing algorithm for finding signal components in the spectrum. But it is possible to use limiting the frequency range in the digital domain too to achieve higher frequency resolution or more accurate bandwidth estimation.

Advanced signal and data processing

The search intercept receiver is further enhanced with record and replays of raw data (optional), support libraries with predefined scanning tasks for random and systematic frequency list and provide statistical database of the results. (optional)

Result database

The results of the task are presented in the form of result log records for further processing by external command and control posts. Each log record contains the basic parameters of the emission. Basically the main parameter of the record is the carrier frequency of the signal. The record contains a sub record of signal timing which shows the signal activity by recording the time of signal emission using the GPS synchronized time stamp. (optional) The result log can be used for further higher-level analysis. (preliminary)

Wide-band direction finding signal processing

The search intercept receiver is able to process the angle of arrival (AOA) for all of the incoming signal components in the spectrum to provide bearing spectrum. Unlike traditional narrowband radio direction finding receiver (RDF) systems, the SRS-3000 wideband DF capability provides simultaneous real-time direction finding information for each and every signal within the actual receiver search range. This is comparable to having thousands of parallel narrowband radio direction finding subsystems which can be simultaneously tasked to determine direction on all detected signals within the search range. This allows the search process to be qualified by direction providing search intercept and monitoring collection of signals only from directions of interest. This is an essential capability for the identification and location of some low probability of interest signals, such as frequency agile signals. The integrated wideband direction data is propagated throughout the receiver programming interface (API) and is integrated into new bearing spectrum and mapping displays. The new displays include a spectrogram color-coded by direction.

Displays of search intercept receiver with power and bearing spectrum

Antenna systems
The radio direction finding (RDF) antenna consists of 8-element circular array with derived DF reference. The antenna system also includes a separate GPS antenna for location and time reference. Mobile versions of the antenna contain fluxgate compasses to provide antenna orientation data to the DF system.

Mapping functions
The new integrated mapping facility links to the bearing displays and mapping server allowing signals of interest to be instantly located on a map. An integrated internal mapping facility sends a data message to the map server component which is connected to the third party map visualization program to display a line of bearing. Multiple SRS-3000D WDF systems provide multiple DF overlays allowing signal location by crossing lines of bearing. The triangulation function is implemented in the map server. In addition, an API is available for customer specific mapping packages.

Essential features

High speed integrated wideband search, collection and wideband direction finding for 20 - 3000 MHz (front-end and tuner dependent)
Equivalent to thousands of simultaneous parallel narrowband direction finding systems
Allows search and collection processes to be qualified by direction-of-interest
Integrated mapping facility plots emitter lines-of-bearing on different map-ware toolsets
Variety of wideband DF subsystems to provide solutions for mobile, portable and stationary fixed-site site applications.

SRM-3000 QUADRUS Digital Multi-channel
Monitor and Collection Receiver

Features

¨ Compact design with graphical user interface

¨ Up to 40MHz wide instantaneous real-time bandwidth

¨ Real-time IF panorama display by complex FFT algorithm

¨ Excellent instantaneous dynamic range

¨ High channel selectivity by digital filtering

¨ Excellent precision and sensitivity

¨ Flexible compatibility for system integration

¨ Raw data recording (option)

¨ Signal pre-classifier (option)

¨ Direction finding (option)

Product description

The receiver consists of the usual components of digital monitoring intercept receiver:

¨ RF front-end,

¨ HF/IF digitizer,

¨ Digital filtering and

¨ Digital signal processor.

The SRM-3000 is a broadband, digitally implemented monitoring receiver. With a frequency pre-selector it can be used in HF bands as direct digitized receiver. (DDR) The frequency range could be extended using a VHF/UHF receiver front-end tuner with wide-band IF output. The receiver digitizes the incoming signal in its instantaneous (real-time) bandwidth. Its digital receiver channels can be tuned to given frequency in its real-time bandwidth. The data streams of the channels are processed by the digital demodulators, supporting usual number of carrier modulation waveforms and bandwidths of wireless emitters. The receiver consists of the RF front-end, digitizer and data capturing unit implemented as a computer add-on card using desktop PCI form factor and the associated driver, signal processing and user interface software components. For forming a full-functional monitoring receiver the basic components are installed in a high-grade industrial interface computer.

Digital receiver concept

High-tech hardware implementation

Digital channel selection and filtering

The front-end of the receiver transforms the selected frequency sub-band to the IF with maximum bandwidth, which is equal with real-time instantaneous bandwidth of the receiver. The digital down-converter (DDC) tuner channels of the digital platform are used to select the required channel in the incoming bandwidth of the signal. After the down conversion to the base-band quadrature (IQ) samples the bandwidth limitation and decimation is implemented. Before the demodulation further conversion and filtering is available inside the digital IF bandwidth.

Advanced signal and data routing

The monitoring receiver is further enhanced with recording and replay of the demodulated audio or raw IQ data to a disk file. Beyond the disk recording facility the receiver program is able to send out the demodulated or raw IQ data trough the IP network.

Sophisticated signal classifier

The digital signal processor of the receiver contains sophisticated algorithms for classifying the incoming signal. The occupied bandwidth and the modulation format can be determined by the receiver, which helps to extend the database record and choice the applicable demodulator.

Direction finding signal processing

The monitoring receiver is able to process the angle of arrival (AOA) for all of the incoming signal components in the IF spectrum to provide IF bearing spectrum.

Antenna systems
The DF antenna consists of 8-element circular array with derived DF reference. The antenna system also includes a separate GPS antenna for location and time reference. Mobile versions of the antenna contain fluxgate compasses to provide antenna orientation data to the DF system.

SDF-3000 ALMOS Compact Multi-mission
Direction Finding Receiver

Features

Full functional scanning and monitoring receiver

· Built-in direction finding capability based on digital bearing processor

· Full 360 degree direction coverage

· Automatic North direction calibration using electronic compass

· Built-in GPS receiver for positioning of and time synchronization

· Well readable multifunctional day-light graphical LCD display

· Fully computer controllable

· Featured status and measurement acquisition and replay (with GUI software)

· Mapware based visual evaluation and location fixing (with GUI software)

· Optional data radio control facility for integrated system application

Product description

This integrated Scanning Receiver/Radio Direction-Finding (RDF) system can be used for stand-alone monitoring and direction finding of communications in the HF/VHF/UHF bands. The system is able to automatically search a given frequency band and store the active channels (frequency search) and subsequently scan the stored channels from its internal memory channel bank (memory scan). The equipment is shipped in a custom, rugged case with a rapid-deployable, portable antenna. The antenna system contains an electronic compass with an automatic North reference direction for bearing calibration. A built-in Global Positioning System (GPS receiver is used for determining the actual location of the equipment. An optional data radio transceiver or Internet connection may be used to transmit DF results, parameters and status information to a remotely-located or distant control. In the control center the received data or the logged offline data can be used for geo-location of target radio transmitters using the optional triangulation software and/or displayed on a map at the center’s workstation. Off-line processing of the measured data is possible using the system’s log files.

Construction

The equipment placed in 160mm W X 80mm H box with 160mm dept. The operating panel is in the front with the power switch and a headphone connector, the back panel contains all of the external connectors.

Man-machine Interface

The man-portable scanning receiver and direction finder has an extremely intuitive man-machine interface based on a multifunctional LCD display and special backlit touch-screen display that allows convenient access to all DF functions under any operating conditions. In the normal operation mode, the display shows the actual frequency, level of the received signal, the squelch setting level, and the measured line of bearing (LOB). The left part of the display contains a graphical representation of the bearing value for quick, “at-a-glance” evaluation of the measurements.

Remote control user interface

The remote control software is able to control up to 4 DF equipments, but more copy of the program could run in same time to increase the number of the controlled receiver in larger DF systems.

Map-based visualization

The remote control software is able to send the collected measured bearings to digital map based visualization programs, where the actual location of the DF station is based on the GPS coordinates.

Recording ana alalysis feature

The log acquisition function may be used to store all of main parameters like frequency, squelch level, received signal level, measured bearing, position (GPS) with a synchronization time stamp provided in the system’s internal memory. The stored parameter file can be accessed via the user interface on the equipment itself or through a connected computer using the remote control software to reproduce an entire mission’s data. The control software can be used for archiving the collected log for historical, analytic or future mission planning.

Optionally, the DF receiver unit may be equipped with an internal solid-state memory card-based voice recorder. This device can be used to record voice communications for future analysis and synchronize them to logged measurements using the stored GPS time data. Recordings may be played back on the system and of course, it can link to an external tape, solid-state or digital recorder for archiving the recordings.

The result database

The results of the task are presented in the form of result log records for further processing by external command and control posts. Each log record contains the basic parameters of the emission. Basically the main parameter of the record is the carrier frequency of the signal. The record contains a sub record of signal timing which shows the signal activity by recording the time of signal emission using the GPS synchronized time stamp. The records contain all of other parameters of the signal including signal level, bandwidth, modulation. The result log can be used for further higher-level analysis.

Automatic positioning

The DF receiver equipment has a built-in electronic compass in the antenna subsystem. This means that automatic calibration of the bearing measurement is done without any human interaction. The displayed bearing can be relative (to the antenna head) for homing operations or absolute (to the magnetic north) for geo-location measurements. The equipment’s position is accurately and continuously determined through the built-in GPS receiver using geographical coordinates resulting perfect for mobile operations.

Search intercept receiver system under integration

Receiver remote control from notebook computer

Search receiver system with notebook control

Search and intercept receiver system

High-power jamming amplifiers

High-power jamming amplifiers

High-power jamming amplifiers

3.5KW out power at amplifier

Intergrated jamming station

VHF radio direction finding antenna

UHF radio direction finding antenna

VHF UHF radio direction finding antenna

VHF radio direction finding antenna

VHF transportable radio direction finding antenna

VHF transportable radio direction finding antenna

VHF mobile radio direction finding antenna

VHF mobile radio direction finding antenna

UHF mobile radio direction finding antenna

Compact radio direction finding receivers

Radio direction finding receiver remote control

Radio direction finding receiver remote control