JED - July 2009 - (Page 33)

TECHNOLOGY SURVEY SAMPLING OF COMINT AND DF RECEIVERS By Ollie Holt T his month’s technology survey takes a look at communications intelligence (COMINT) and direction-finding (DF) receivers. As you review the results, you will notice it is mostly a review of COMINT receiver systems. The receivers’ capability to perform DF is listed in one of the columns under the type of DF it performs. Most receivers provide a DF solution as long as they have more than one parallel receiver channel. For a receiver to generate a DF solution, all that is needed are two measurements of the signals parameters made by two similar receiver systems at the same time but from two different receiving locations. By comparing the received signals phase, amplitude or time of arrival, a DF solution can be generated. The accuracy of the DF solution is dependent on how well the system can measure the phase, amplitude or time, and how much information is known about the receiving antennas, their locations with respect to each other and the number of parallel channels. In terms of what is new with COMINT receivers, you first will notice that this survey contains complete receiver systems and also receivers that are simply VME cards ready to be configured into complete receiver systems. These same VME cards or similar ones from other manufacturers can be used in the complete COMINT receiver systems listed in this survey. The VME cards contain all the necessary hardware and firmware/software to receive, digitize and demodulate the signals, but do not contain the power source, control structure and mechanical housing provided by other systems. A COMINT receiver manufacturer either would have to supply or purchase these additional items to complete the COMINT system. The days of a COMINT receiver manufacturer specifying the correct amplifier, mixer or local oscillators and installing them into a receiver system quickly are going away. Today, the COMINT receiver manufacturer simply can purchase a set of VME or the new emerging higher-speed and denser-format standard cards that contain a complete receiver channel with RF as the input and digits as the output. In some configurations, the digits already have been processed into demodulated digital representations of the information being transmitted. In other cases, the output simply is a digital representation of the radio frequency (RF) signal ready for additional processing required to retrieve the desired information. So the task of developing a COMINT or almost any type of receiver is becoming one of preconditioning the RF signals and then presenting them to RF-to-digital receiver cards and providing the correct firmware or software to demodulate the signal to retrieve the needed information. The science then becomes one of developing the processing schemes to retrieve the information and present it in a usable manner. The Journal of Electronic Defense | July 2009 33 COMINT AND DF RECEIVER SAMPLING This survey was performed in the same manner as the previous surveys, with a set of questions sent to known COMINT and DF receiver manufacturers. The surveyed companies were asked to provide information for up to five of their receiver products for inclusion in this survey. Only information supplied by the survey respondents was used in this compilation. UPCOMING SURVEYS: SIGINT Antennas and ELINT Systems Our next survey, in the August 2009 JED, will cover signals intelligence (SIGINT) antennas. Our final 2009 survey, in the November edition, will cover electronic intelligence (ELINT) systems – please e-mail to request a survey questionnaire.

Table of Contents for the Digital Edition of JED - July 2009

JED - July 2009
The View From Here
From the President
The Monitor
Washington Report
World Report
Advancing TWT Technology
Technology Survey: COMINT/DF Receivers
EW 101
AOC News
JED Sales Offices
Index of Advertisers
JED Quick Look

JED - July 2009