REDB GENERAL EXPLANATION OF TERMS

The following alphabetical listing identifies and broadly defines the Fields employed in the Radar Emitter Database (REDB).  All data is entered into the base on a mode per line basis except where there may be conflict between those sources of information then, additionally, data is entered on a mode & source per line basis. Each line of data has a separate mode number: For quick reference, where there is an expanded explanation, the Database Field Title is emboldened and the Section number is shown in Red

Field TitleDefinition and Section Number

AEGAntenna Gain of the main beam at the 3dB point is given in dBs

AGbwAgility Bandwidth is the maximum bandwidth over which the radar is known or reported to be frequency agile or tuneable, for a given transmission source. Solutions are recorded in MHz at 100kHz intervals. Results of 25 MHz or less usually indicate the pulse receiver’s reported bandwidth is simply governed by the transmission pulse duration.

Alias 1, 2These fields note the major alternative names, designators or sequence of characters by which an emitter may also be known but they only carry one alias each. All additional lesser aliases are stored in Alias 3.

Alias 3This field retains all other aliases by which an emitter might be known.

AntennaBasic description of antenna type. This has three associated fields; Height (cm), Width (cm) and Diameter (cm). The diameter field is also used to record the turning circle dimension when given for any 360º scanning radar. This data may also be used to support radar hazard calculations.

Ass PlatformRecords the commercial or military PLATFORMS associated with the named EMITTER or the location by name or latitude and longitude. Where the information is complex individual solutions may be followed by a country code in parenthesis. e.g. (UK)

Ass WeaponMajor WEAPONS known to be fitted on the associated PLATFORM or to be commonly associated with the named EMITTER for the indicated USER Country(ies)

AvPWAverage transmitter power in Watts. When they are both available in a single emitter mode, AvPW and PEPkW values are used to calculate the Duty Cycle (DCpow). (See below)

AzArcThe AzArc Fields define the number of degrees in azimuth through which the antenna array may be made to train or scan, for other than circular scan systems (0° to 360° - scan code A) either under local or remotely controlled conditions. Section 9.

AzArcLAzArcL states the number of degrees to the left of a selected bore-sight through which the emitter’s antenna may scan. Mainly applicable to sector scanners (scan code B) and active phased arrays (scan code Pa) with a look forward, look back capability. Section 9.

AzArcRAzArcR gives the number of degrees to the right of a selected bore-sight through which the emitter’s antenna will scan. This will normally be 360° indicating a circular scanner, scanning clockwise, or an equal number of degrees to that recorded in the AzArcL which would imply a sector scanner or an active phased array (scan code Pa) with a look forward, look back capability. Section 9.

Note:An example of a circular scanner scanning clockwise would be 0.00 – 360.00 in AzArcL and AzArcR respectively. If the antenna was scanning anti-clockwise then 360.0 – 0.0 would be recorded respectively. An Omni-direction emission is recorded as –360.0 & 360.0 respectively. In the case of a scanning phased array the result might be given as 300.00 – 420.00 respectively, implying that there is a 60 degree look back and look forward capability about any point in a 360 clockwise rotational period. Section 9.

BandThis field shows the (NATO defined) RF band in which the transmission(s) takes place.  If the RF straddles two adjacent bands, or transmits in two non-adjacent bands, both bands will be shown. e.g. EF. If the emitter is multi-banded, such as a radar jammer, it will be indicated by a hyphen between the extreme band values, e.g: H-J. NATO band designators are tabulated at Section 16.

BeamwidthsWhere a beamwidth has not been reported but the antenna’s dimensions are available, they may be used to approximate the antenna beamwidths. See page 46 in Section 9.

Chirp [& Chip]States the changing RF value (Chirp) in MegaHertz (MHz) caused by intra-pulse modulation. The suffix indicates whether the RF changes up (U) or down (D) with time, or whether their direction is unknown (Z). (e.g. 25D would indicate a 25 MHz Downward frequency transition). Where phase modulation (PMOP) is employed, this field will record the number of phase steps (Chips) within the pulse. A Chip is defined as the shortest period of time for which the pulse exhibits a fixed phase value.

This field may also be used to indicate an audio frequency shift as used in Frequency Shift keying (FSK), but in this case no directional or pulse compressive information will be shown.

CoPDGives the duration of the processed compressed pulse in microsecs. Although this characteristic cannot be intercepted, knowledge of its value indicates a radar's minimum target discrimination range and, for ship or airborne emitters, the increased probability of a military platform application. Section 8

Cos2Gives the elevation angular cover in degrees for a cosecant-squared antenna pattern. See also VBW.

CSFThis field allows for a simple, two-character indication of any Complex Scan Function that may be employed. These antenna scan functions are explained in detail at Section 9.

Duty CycleThe reported Duty Cycle of an emitter is recorded in one of two fields down to six decimal places. The values in these two fields may take one of three forms in the following priority order:

DCpintIf there is no equation in this cell any value is as reported from an authoritative source, which will be listed as a data source.

DCpintGiven no authoritative source for the DC but the availability of PRIme and PDme data, then the Pulse Duration divided by the Pulse Repetition Interval (in microsecs) is recorded in the DCpint field and will be recognised by an equation in the cell when it is selected. [ = sum (PDme / PRIme) ].

DCpowWhere power values only are available in a single mode, then the result of Average Power divided by Peak Power (in Watts) is recorded in DCpow:

[ = sum (AvPW / PEPkW) / 1000 ].

It should be noted that given sufficient data both DCpint and DCpow may be satisfied, therefore, their values may be compared. (see also page 27)

Diameter cmA dish or parabolic shaped antenna aperture’s diameter is recorded in centimetres.

ElArcThe ElArc fields define the number of degrees in elevation through which the antenna may be trained or scanned under local or remote control conditions.

ElArcNElArcN normally defines the number of degrees in elevation below the emitter’s stabilized horizon through which the antenna may be made to scan electronically or mechanically but note, this does not have to be a negative number.

ElArcPElArcP normally defines the number of degrees in elevation above the emitter’s stabilized horizon through which the antenna may be made to scan electronically or mechanically and may be any value up to 180°. i.e. where a scanner can be made to pass through the zenith and look ‘backwards’. In the case of airborne emitters, this may also be a negative value. (See US Research labs WASSAR radar)

ERPkWEstimated Radiated Power level in kW [theoretically = PEP x AeG].  However, solutions given are those supplied by the emitter's manufacturer only. Because PEP and AEG are so often misreported they are not computed.

FN1Identifies the sensor's operating platform by generic type in Sections 11.

FN2Identifies the sensor's primary operating function in Sections 13.

HBWHorizontal 3dB Beam Width of the antenna in degrees

Height cmThe antenna aperture’s height is recorded in centimetres.

Height ftA radar’s detection height is given in feet for a particular target RCS. Where the RCS is not known the radar’s reported maximum (instrumented) operational height is recorded.

InstrumentedThis is the PRF calculated from the instrumented target detection range, also called the maximum theoretical unambiguous range

PRF(MTUR – see below), recorded in the Range km field. Further

details are in Section 6.

ISDTabulates the emitter’s first reported In-Service-Date where a User is listed, otherwise it indicates the equipment’s promotion year.

MODEEach line of data is considered to be a Mode, where the transmission characteristics of a given emitter differ from those of the same emitter in the previous line. Each Mode carries a separate Mode Number

MTBFIndicates the reported Mean Time Between Failures, in hours

MTTRIndicates the reported Mean Time To Repair, in minutes

MTURMaximum Theoretical Unambiguous Radar Range. Detail in Section 6.

NATIdentifies the Country of origin of the sensor’s Manufacturer from the Country Decode listing at Section 12.

NfThis is the radar receiver Noise factor expressed in decibels.

PCrThis is the reported pulse compression ratio. Section 8.

PD TablesLists the minimum (PDmi) median (PDme) and maximum (PDma) values of Pulse Duration in microseconds (µs)

PDCThe Pulse Duration Characteristic field gives a simple indication of the pulse’s stability at Section 7

PEPkWPeak Emitter Power in kW. (emitter tube power). When they are both available in a single emitter mode, AvPW and PEPkW values are used to calculate the Duty Cycle (DCpow). (See above)

PMCThe Pulse Modulation Characteristic identifies the modulation type or waveform technique employed from the listings at Section 8

PolA single character code that identifies the transmission polarisation from the listing at Section 10.

PRC Gives the Pulse Repetition Characteristic applicable to the PRF & PRI Fields from the codes at Section 6.

PRF FieldsLists the minimum (PRFmi), median (PRFme) and maximum (PRFma) values of Pulse Repetition Frequency in pulses per second (pps) or, in the case of data transmissions, the minimum, median and maximum data rates respectively in bits per second (bits/sec).

PRI FieldsTabulates the minimum (PRImi), median (PRIme) and maximum (PRIma) values of Pulse Repetition Interval in microsecs, which are calculated as the mathematical reciprocals of PRFma, PRFme and PRFmi respectively.  When available the PRIme data are used to calculate the Duty Cycle (DCpint). (see above).

Radar NameIndicates the sensor manufacturer's product name, identifying number or, typically, the radar's official military designator. The US Army Navy (AN/…) military nomenclature scheme is tabulated at Section 19. However, there are occasions when a radar’s location and its parameters are known but not its identity. In these cases the radar is given the arbitrary name of its location. For example PATSCHERKOFEL RADAR which is a weather profiling radar in Austria. If neither the name nor location of a radar is known it is given a ZZ+ numeric notation.  The naming of emitters is quite a complex issue and is further amplified at Sections 14 [Radar Nomenclature] and Section 15 [Radar Acronyms].

Range kmA radars detection range is reported in kilometres for a given target RCS. Where the RCS is not known, if available the radar’s reported maximum operational or instrumented range is recorded.

RemarksA free text field used to comment about any aspect of the emitter; its technology, ownership or operation.

RFbStates the number of elevation beams generated by the radar’s antenna and associated transmission feed assembly.

RFCLists, as a single character code from Section 3, the radar's basic Radio Frequency Characteristics. (See also Sections 4 & 5)

RF FieldsLists the minimum (RFmi) and maximum (RFma) Radio Frequency values in MegaHertz (MHz), down to three decimal places, between which the emitter may be found to operate.

RFsThe number of radio frequencies (RFs) used either singly, simultaneously or sequentially during one complete cycle of a transmission. Section 5

RxSenGives the radar receiver system sensitivity in –dBm. This is usually reported as the minimum discernible signal level.

SLLStores the strongest (normally the first) Side Lobe Level in dBs without reference to any angular offset from the main beam boresight.

SP fieldsTabulates the minimum (SPmi), median (SPme) and maximum (SPma) Scan Periods in seconds for primary scans or the Hertzian rates for secondary or complex scans. Thus it is important these fields are read concurrently with field ST, to ensure correct interpretation of antenna motion type and associated rate.

STIndicates a transmitting antenna's Scan Type from the coding at Section 9. (see also CSF)

StatusThis field remains blank unless the emitter is known to be under development (Dev) is a demonstration model (Dem) or is obsolete (Obs). It is designed to assist data sorting.

STGGives the number of PRF / PRI Stagger levels employed.  Also used to indicate the number of pulses in a group transmitted as one of a regular pattern of groups. The translation of Stagger or Group will be indicated by the use of codes G, K, L or R in the PRC Field. See Section 6.

Target RCSThe targets Radar Cross Section (RCS) is given in whole or fractions of a metre squared (e.g. 2m2). There are two associated fields where the detection values for Range (km) and Height (ft) can be recorded for a given target RCS.

UserIdentifies known User Countries by the Country Code listed at Section 12.

VBWThis is the Vertical Beam Width of the antenna in degrees.  Where the radar antenna is known to have a cosecant-squared radiation pattern, the maximum angle of the cosec2 cover diagram will be quoted in the Cos2 field. Generally, any vertical angle greater than 10 degrees can be considered to be a cosec2 radiation pattern if multiple elevation beams are not reported in the RFb Field. Where values appear in both the VBW and Cos2 fields, this would imply the dimension of an individual beam and the sum of the beams respectively that create the cosecant-squared pattern. Where the result might indicate an alternative switched antenna beam function (without knowledge of the antenna scan pattern) it will be noted in the remarks field.

Width cmThe antenna’s aperture width is recorded in centimetres.

ZAs a single character, wherever it appears in the database, Z is taken to mean Undetermined or Unknown.

Aug 2008.