AN/WSN-5   SINS Ship’s   north,   east,   and   vertical   velocity components The  AN/WSN-5  is  a  stand-alone  set  that  replaces the  MK  19  MOD  3  gyrocompass  in  the  following class  ships:  CG  16,  CG  26,  CGN  9,  CGN  25,  CGN 35,  CGN  36,  CGN  38  (except  for  CGN  41),  DDG  37, DD  963,  and  LHA  1.  It  also  replaces  the  AN/WSN-2 stabilized  gyrocompass  set  in  DDG  993,  DD  997,  and CGN  41  class  ships. Functional Description The  AN/WSN-5  has  the  same  output  capabilities as  the  AN/WSN-2. It   uses   an   accelerometer- controlled,  three  axis,  gyro-stabilized  platform  to provide   precise   output   of   ship’s   heading,   roll,   and pitch  data  in  analog,  dual-speed  synchro  format  to support  ship’s  navigation  and  fire  control  systems. Ship’s  heading  and  attitude  data  are  continually  and automatically derived while the equipment senses and processes   physical   and   electrical   inputs   of   sensed motion  (inertial),  gravity,  earth’s  rotation,  and  ship’s speed.  The  equipment  has  an  uninterruptible  backup power  supply  for  use  during  power  losses,  and  built- in test equipment (BITE) to provide fault isolation to the  module/assembly  level. Characteristics In  addition  to  the  common  functions  described above,  the  AN/WSN-5  adds  an  increased  level  of performance  to  serve  as  an  inertial  navigator  and provides  additional  analog  and  digital  outputs. Additional  data  provided  includes  position,  velocity, attitude, attitude rates, and time data in both serial and parallel   digital   formats,   providing   a   variety   of interfaces.   The   AN/WSN-5   commonly   exists   in   a dual-system  configuration  on  surface  combatants. Some   examples   of   AN/WSN-5   digital   data   outputs are: 1.  Two  Naval  Tactical  Data  System  (NTDS) serial  channels  transmitting: Ship’s  heading,  roll,  and  pitch Ship’s heading rate, roll rate, and pitch rate Ship’s  latitude,  longitude,  and  GMT 2.  Two  MIL-STD-1397  NTDS  type  D  high-level channels to an external computer 3.  One  MIL-STD-1397  NTDS  type  A  slow,  16- bit,   parallel   input/output   channel   to   a   Navigation Satellite   (NAVSAT)   receiver   AN/WRN-5A,   Global Positioning  System  (GPS)  receiver  AN/WRN-6,  or I/O   console. 4.   One   serial   AN/WSN-5   to   AN/WSN-5   digital link that provides alignment data, Navigation Satellite (NAVSAT)   fix   data,   calibration   constant   data,   and other  navigation  data  to  the  remote  AN/WSN-5. 5,  An  additional  variety  of  input/output  NTDS channels,   depending   on   which   field   changes   are installed. SATELLITE   NAVIGATION   SYSTEMS Scientists   realized   that   navigation   based   on satellite  signals  was  possible  after  listening  to  the beep  generated  by  Russia’s  first  artificial  satellite, Sputnik  I.  They  noticed  a  shift  in  the  received  radio frequency   signals   as   the   satellite   passed   by.   This shift,  known  as  the  Doppler  effect,  is  an  apparent change  in  a  received  frequency  caused  by  relative motion  between  a  transmitter  and  a  receiver.  As  the distance   between   the   transmitter   and   the   receiver decreases, the received frequency appears to increase. As  the  distance  increases,  the  received  frequency appears to decrease. With  this  discovery,  scientists  were  able  to  show that by accurately measuring a satellite’s Doppler shift pattern,   they   could   determine   the   satellite’s   orbit. They then determined that by using a known satellite’s orbit,  a  listener  could  determine  his  own  position  on the earth’s surface by observing the satellite’s Doppler pattern. Following  the  first  successful  satellite  launch  in April  1960,  the  U.S.  Navy  Navigation  Satellite 1-5