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International Maritime Meteorological Tape (IMMT-4) Format (deck 926) (by ESRL)

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Table 1. Field-by-field mapping between the International Maritime Meteorological Tape (IMMT-4) format (left columns) and the International Maritime Meteorological Archive (IMMA-0) format (right columns). Mappings of fields configurations between IMMT and IMMA are direct (no transformation) except as listed below this table for fields marked with an asterisk "*" (note: preliminary information, under development).
IMMT-4*IMMA-0
abbr
*it
yr
mo
dy
hr
lat
lon
*lat
*lon
*hi
vi
*h
vv
*n
*d
*wi
w
*at
at
*dpti
dpt
dpt
*slp
ww
w1
w2
*nh
*cl
*cm
*ch
*sst
sst
si
wmi
wp
wh
*sd
sp
sh
is
es
rs
os
*op
id
c1
(field not presently mapped)
qci
ix
ir
rrr
tr
*wbti
wbt
wbt
a
ppp
ds
vs
*sd2
sp2
sh2
*ic1
*ic2
*ic3
*ic4
*ic5
fm
(field not presently mapped)
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi1
qi21
hdg
cog
sog
sll
*slhh
*rwd
rws
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)
(field not presently mapped)

* Following is a list of exceptions, organized by IMMA field name, to a direct mapping (IMMT=IMMA) of individual input IMMT field configurations (on the left) to IMMA output configurations (on the right). Some outstanding questions in the transformation method are highlighted.

IT
"3"="0"
"4"="1"
"5"="2"
LAT
quadrant 3=negative LAT
quadrant 5=negative LAT
LON
quadrant 5=negative LON[+360.0]
quadrant 7=negative LON[+360.0]
HI
"0"="0"
"1"="1"
"2"="1"
"3"="0"
VI
"0"="0"
"1"="0"
"2"="1"
"3"="1"
H
"/"="A"
N
"/" and blank (assumed missing)=missing
D
"00"="361"
"99"="362"
tens=tens*10
WI
"0"="0"
"1"="1"
"3"="3"; related field action: knots=knots*0.51444444444444444444 for both W and RWS
"4"="4"; related field action: knots=knots*0.51444444444444444444 for both W and RWS
AT
sign 1=negative AT
DPTI
"0"="0"
"1"="0"; related field action: negative DPT
"2"="2"; related field action: negative DPT
"5"="1"
"6"="1"; related field action: negative DPT
"7"="3"; related field action: negative DPT
SLP
hundreds<500.0=hundreds+1000.0
NH
"/" and blank (assumed missing)=missing
CL CM CH
"/"="A"
SST
sign 1=negative SST
SD
"99"="38"
OP
"4"=missing (note: this configuration is not mapped to IMMA, because the meaning of that value changed from IMMT-III to IMMT-IV)
WBTI
"0"="0"
"1"="0"; related field action: negative WBT
"2"="2"; related field action: negative WBT
"5"="1"
"6"="1"; related field action: negative WBT
"7"="3"; related field action: negative WBT
SD2
"99"="38"
IC1 IC2 IC3 IC4 IC5
"/"="A"
SLHH
sign 1=negative SLHH
RWD
"000"="361"
"999"="362"

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