TM 1-1510-218-10 3B-47 GPS     sensor.          Below     the column   labeled   SAT   appear the numerical designations of various satellites visible to the GPs  sensor.    An  asterisk  to the   far   left   of   the   identifier indicates that the GPS sensor is     not     using     the     specific satellite in its position solution.    The  SNR  (signal  to noise  ratio)  column  provides signal strength information for individual   satellites.      Typical SNR  values  will  be  in  the  30 to  55  range.    The  elevation above the horizon is provided by the ELE column.  Elevation is   displayed   in   degrees   and will typically be in the range of 5"  to  90°.    The  last  column, HLT,     indicates     the     health state  of  each  satellite.    Three states are possible: GD (signal is good), WK (signal is weak), and BD (signal is bad). (9)   GPS Restart Page.   This page is used to re-initialize (restart) the GPS sensor. (a)   Date Line (DATE).   This line displays the Greenwich date in the order of day-month-year. (b)   Time Line  (GMT).    This  line  displays Greenwich Mean Time in hours and minutes. (c)   Waypoint   Identifier   Line   (WPT   ID).   The  space  after  WPT  ID:  is  a  data  entry  field  where the    present    position    waypoint    identifier    may    be entered. (d)   Latitude and Longitude Lines (POS.).   The   latitude   and   longitude   of   the   aircraft's   resent position,   which   has   been   derived   from   either   their position  sensors  or  the  waypoint  identifier  (WPT  ID) will  be  displayed  here  or  may  be  manually  entered here. (e)   Mode Line. The mode field (MODES) allows one of three restart modes: NORMAL, COLD, or SEARCH SKY to be selected. (f)    Estimated   Groundspeed   Line   (EST GS).      Estimated   groundspeed   is   manually   entered here. n.     Data 2 Menu Page.  The data 2 menu page lists  the  actual  data  pages  that  can  be  selected  from its menu.  Specific data pages are selected by entering the corresponding menu number into the SEL MENU ITEM: data field and pressing the   ENTER  key.    They may  also  be  selected  by  placing  the  cursor  over  the menu item and pressing the ENTER key. (1)   Navaid   Page.      This   page   is   used   to display the frequency, type, class, elevation, magnetic variation,  latitude  and  longitude  of  a  selected  navaid.   If  the  selected  navaid  is  contained  in  the  data  base, the   above   information   will   be   displayed   when   the navaid  identifier  is  inputted  into  the  station  identifier field.  A user-defined navaid is created by entering the above  data  into  their  respective  fields  and  approving the page. STA IDENT     – Navaid identifier. FREQ:     – Navaid  frequency  or  TACAN channel  depending  on  which format    is    selected    on    the waypoint page. When TACAN  channel  is  selected, FREQ:  will  be  replaced  with CHNL:. TYPE> VORTAC     – Displays  the  type  of  navaid.   Also used when a user navaid is  being  defined,  as  a  cyclic field   in   conjunction   with   the CLEAR    key   to   choose   the type   of   navaid   from   among the   following   choices:   DME, VOR/DME, VORTAC, TACAN, ILS/DME or VOR. CLASS> HIGH     – Displays  the  class  of  navaid.   Also used when a user navaid is being defined.  It is a cyclic field  and  is  modified  with  the CLEAR    key   to   choose   the class     of     navaid     from     the following choices: LOW, HIGH, TERMINAL, and UNDEFINED. ELEV: FT:     – The  elevation  (to  the  nearest 10  feet)  of  the  navaid  being displayed or defined. MAG VAR:     – The published magnetic variation    in    degrees    of    the navaid     being     displayed     or defined. LAT: LON:     – The  position  of  the  navaid  in latitude and longitude. APPROVE?     – A cursor field used to approve a user defined navaid.