Specifications

50
Table 5.7.4. Organization and significance of the system file data.
System file
word no (4 bits)
System file word
(12 bits)
Significance
0 bits 11-8: T
p
= 0
bit 7: M = 1
bit 6: T = 0
bit 5: F
bit 4: C = 1
bits 3-0: T
n
always 0 (DWR), always 10 (WR-SG)
always 1 = MkII transmission format
always 0, figure of merit of GPS position solution
1 = GPS position fix,
0 = no solution available or old position
always 1 = GPS position module OK
T
n
transmission number (1-8)
1 bits 11-0: Hrms H
rms
= Hrms/400
H
rms
root mean square wave height = √m
0
, H
s
= 4
√m
0,
units m
2 bits 11-8: reserved
bits 7-0: fz
f
z
= fz,/400 units Hz
T
z
= 1/f
z
, T
z
mean time between zero-up crossings,
units Hz
3 bits 11-0: PSD PSD
max
= 5000 exp(−PSD/200)
PSD
max
peak power spectral density, units m
2
/Hz
4 bit 11: reserved
bit 10 reserved
bits 9-0: Tr
T
r
= Tr/20 − 5
T
r
reference temperature, units ºC
internal check (DWR with water temperature option)
always 25/0 (WR-SG with/without option)
5 bit 11: reserved
bit 10 reserved
bits 9-0: Tw
T
w
= Tw/20 – 5
T
w
water temperature, units ºC
6 bits 11-4: t
ol
bit 3: reserved
bits 2-0: B
t
ol
operational life (see subsection 5.10.2)
units weeks
B battery status bits (see subsection 5.10.2)
7 bit 11: sign
bits 10-0: Av0
A
v0
= Av0/800
sign sign bit, 0 = pos, 1 = neg
A
v0
vertical accelerometer offset, units m/s
2
always 0 (DWR-G)
8 bit 11: sign
bits 10-0: Ax0
idem x-axis accelerometer offset (DWR-MkIII)
always 0 (WR-SG, DWR-G)
9 bit 11: sign
bits 10-0: Ay0
idem y-axis accelerometer offset (DWR-MkIII)
always 0 (WR-SG, DWR-G)
10 bit 11: sign
bits 10-0 LatMSB
11 bit 11-0: LatLSB
Lat = 90(Lat/2
23
)
sign sign bit 0 = north, 1 = south
Lat Latitude, units degrees
12 bit 11: sign
bits 10-0 LongMSB
13 bit 11-0: LongLSB
Long = 180(Long/2
23
)
sign sign bit 0 = east, 1 = west
Long Longitude, units degrees
14 bits 11-8: reserved
bits 7-0: O
O = 360(O/256)
O buoy orientation, units degrees
always 0 (WR-SG, DWR-G)
15 bits 11-8: IncLSB
bits 7-0: IncMSB
I = (90/128) (IncMSB −128 + Inc
LSB
/16)
I inclination of earth magnetic field, units degrees
always 0 (WR-SG, DWR-G)