Table  1-7.—Upper-Air  Observation  Types  and  Reporting  Codes WMO  CODE I D OBSERVATION DATA OB  TYPE S I T E FM   32-IX-PILOT P P — Fixed  Land  Site Upper PIBALs FM   34-IX-PILOT   MOBIL E E — Mobil   Land   Site W i n d FM    33-IX-PILOT-SHIP Q Q — S h i p Reports FM   35-X-TEMP T T — Fixed  Land  Site Upper   level RAWIN-, FM   38-X-TEMP   MOBIL I I — Mobil  Land  Site Pressure RADIO-, FM  36-X-TEMP  SHIP U U — S h i p Temperature D R O P - , FM  37-X-TEMP  DROP X X — Aircraft Humidity SONDEs,   and Winds R A B A L s FM   39-VI-ROCOB RRXX Fixed  Land  Site Upper   level ROCKETSONDEs FM  40-VI-ROCOB  SHIP S S X X S h i p Air   density Temperature W i n d s FM  41-IV-CODAR LLXX Aircraft Upper   level   Pressure Aircraft   (manual) Temperature W i n d s FM  42-XI  AMDAR n o n e Aircraft Upper  level Aircraft  to  satellite Pressure data  relay Temperature Dew  point Winds NOTE: "—" indicates multi-part messages (AA, BB, CC, or DD). The observation time is coded in the third group of the first line of data in the form YYGGI_d. This is the date/time  group,  with  YY  indicating  the  day  of  the month,  and  GG  indicating  the  synoptic  hour  of  the observation. The  I_d is an indicator that is different in each code and will be discussed later. On most reports received via telecommunications circuits,  computers  have  already  “read”  the  code identifier  and  date/time  group  and  printed  a  message header at the top of the bulletin. A single bulletin may contain  several  Part  A,  TEMP  SHIP,  reports  from different  ships,  all  under  a  header  such  as  UUAA 211200Z NOV. The location where the observation was conducted is identified differently in the various code forms. Ship observations   and   mobile   land-observation   sites   are located  by  latitude,  longitude,  and  Marsden  Square coordinates,  which  pinpoint  the  location.  Established land  stations  are  located  only  by  referencing  the international   block   and   station   number   (IIiii)   on weather plotting charts or in the Master Weather Station Catalog. The  identification  groups  "D.  .  .  .D  99L_aL_aL_a Q_cL_oL_oL_oL_o  MMMU_LaU_Lo"  are  used  only  by movable   observation   platforms   to   identify   the observation   platform   and   the   location   of   the observation.   All   ships,   mobile   observation   sites ashore,  and  aircraft  use  these  groups.  As  in  the  Ship Synoptic code FM 13-X SHIP, discussed in module 1, the "D. . . .D" is the call sign of a ship or the call sign or communications  identifier  assigned  to  a  mobile  unit. The  "99L_aL_aL_a Q_cL_oL_oL_oL_o"  groups  are  the  latitude 1-21