Sperry Marine

Appendix 1
Published Radar Characteristics

            Technical characteristics of Sperry Marine's civil MNRs are presented in the following tables. The following points should be borne in mind:
 

  • Many of the characteristics of the Bridgemaster E necessarily have been derived from Type Approval certification documents, rather than directly from the manufacturer, particularly in the case of pulse-rate data.
  • Type Approval certificates show that there are no behavioral differences between the Bridgemaster E180, E250 and E340. Equally, there are no behavioral differences between ARPA, ATA and EPA versions.
        
  • Antenna beamwidth values are estimated from physical size information, except in the case of the River radar series.           
  • Antenna scan rates (see Table 1) for the River radar series have been converted; manufacturer documentation specifies their periodicities (1.3 and 1.9 seconds/rotation).     
  • With the exception of the 12' open array antenna option for the S-band version (this has only one rotation rate), all Bridgemaster radars are capable of switching between two available scan-rates. However, to comply with IMO regulations regarding high-speed craft, variants destined for these vessels have this facility disabled.       
  • For the Bridgemaster family, pulse-rate data (see Table 2) in particular should be viewed with caution. The information provided here is derived solely from Type Approval documentation, and there is unqualified evidence - online documents from unofficial sources - indicating other possibilities. Equally, there is other evidence that provides some independent verification; this takes the form of Type Approval documentation for the Kongsberg DataBridge-10 described in the Koden section, which states that Kongsberg may acquire some transceivers from Sperry Marine's parent (NorthropGrumman) and provides pulse-rate data similar to that of the Bridgemaster E.       
  • Not all X-band versions of the Bridgemaster are documented as being capable of using a 3-kHz pulse rate.
  • The pulse-rate data for the River radar series is converted: as provided in manufacturer documentation, it is specified as inter-pulse periodicity (pulse repetition interval, or PRI).