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Visit NDBC's new TAO Data Download page to access current and historical data for the tropical equatorial Pacific.

Check out our new BuoyCAMs Map - also available at the BuoyCAMs link on the left side menu.

Changes to the DART® II Data Messages
For BPR Firmware Version 2.78

Previously, DART® II technology tsunameters indicated a manually triggered event by adding 100 mm to the water-column heights. New Bottom Pressure Recorder (BPR) firmware (BPR Firmware version 2.78).being deployed in 2009 will no longer add 100 mm to the water-column heights. To distinguish manually triggered events from automatically triggered events, two new message identifiers have been developed – D$f and D$F to be used for the manually triggered events.

Not all tsunameters will be converted in 2009, some tsunameters will still be operating with the old firmware (BPR Firmware Version 2.52) and still include the 100 mm addition to water-column heights and report both manually and automatically triggered events using the D$2 and D$3 message identifiers.

For the manually triggered events of Firmware 2.78, the message ID will change to D$F (upper case letter F) for event hourly mode (formerly all event hourly modes used D$3). The random messages will be changed to D$f (lower case letter f) (formerly D$2). The contents of the new messages, D$F and D$f, remain the same as the D$3 and D$2, respectively, with the exception of the 100 mm addition. D$3 and D$2 are reserved for automatically triggered events in Firmware 2.78.

In addition, a BPR Firmware Version column has been added to the Current Deployment Metadata Spreadsheet (http://www.ndbc.noaa.gov/dart_metadata/dartmeta_public.php)
For further information, please contact the NDBC Data Assembly Center at: dmac@noaa.gov, or telephone 228-688-2835.

First D$f Message Description:

All data in the first message (message sequence number 00 (see Table 1 below)) are values integrated over the base sampling period of 15 seconds, therefore they are at 15-s intervals.

Message Breakdown

<cr>D$fC/I Msg# tt ttTime ts tsTime height
dev1 dev2 dev3 tries * checksum"

<cr> = 0x0D
D$f = message ID
C/I = message status; C=Corrupted, I=Intact
Msg# = Sequential message number; the example message below is the first message and the sequence message numbers start with 00 of event mode.
tt = event trigger designation
ttTime = time (UTC) event detected; corresponds with dev3 (this is the second value that exceeds the detection threshold, see http://www.ndbc.noaa.gov/dart/algorithm.shtml)
ts = time stamp designation
tsTime = time (UTC) of first water column height in this message
height = water column height in millimeters
dev1 = deviation from height in millimeters, 4 hexadecimal characters
dev2 = deviation from height in millimeters, 4 hexadecimal characters
dev3 = deviation from height in millimeters, 4 hexadecimal characters
tries = number of tries to deliver BPR data (up to 3)
* = checksum delimiter
checksum = exclusive OR of all characters preceding "*", hexadecimal

Example Message:

D$fI 00 tt 18:32:45 ts 18:32:00 3772311 00000063006201* 22

Second D$f Message Description:

All data in second message (sequence number 01) are values integrated over the base sampling period of 15-seconds and are at 15-s intervals. The first four observations are repeats of first message (sequence number 00).

Message Breakdown

“<cr>D$fC/I Msg# tt ttTime ts tsTime height
dev1 dev2 dev3 … dev15 tries * checksum"

<cr> = 0x0D
D$f = message ID
C/I = message status; C=Corrupted, I=Intact
Msg# = Sequential message number; this message is 01 of event mode
tt = event trigger designation
ttTime = time (UTC) event detected; corresponds with dev3 (this is the second value that exceeds the detection threshold, see http://www.ndbc.noaa.gov/dart/algorithm.shtml)
ts = time stamp designation
tsTime = time (UTC) of first water column height in this message
height = water column height in millimeters
dev1 = deviation from height in millimeters, 4 hexadecimal characters
dev2 = deviation from height in millimeters, 4 hexadecimal characters

dev15 = deviation from height in millimeters, 4 hexadecimal characters
tries = number of tries to deliver BPR data (up to 3)
* = checksum delimiter
checksum = exclusive OR of all characters preceding "*", hexadecimal

Example Message

D$fI 01 tt 18:32:45 ts 18:32:00 3772311 000000630062706900600061005f005ffffafff9fff8fff8fff7fff6fff401* 21

Additional D$f Message Description:

All D$f data in message sequence numbers 02 - 17 are 1-minute averages of four 15-second samples. The 15-second values used to compute 1-minute averages are ALWAYS: xx:xx:00 xx:xx:15 xx:xx:30 xx:xx45. The 1-minute value time stamp ALWAYS corresponds with xx:xx:00.

Message Breakdown

<cr>D$fC/I Msg# tt ttTime ts tsTime height
dev1 dev2 dev3 … dev15 tries * checksum"

<cr> = 0x0D
D$f = message ID
C/I = message status; C=Corrupted, I=Intact
Msg# = Sequential message number beginning with 02 and ending with 17
tt = event trigger designation
ttTime = time (UTC) event detected
ts = time stamp designation
tsTime = time (UTC) of first water column height in this message
height = water column height in millimeters
dev1 = deviation from height in millimeters, 4 hexadecimal characters
dev2 = deviation from height in millimeters, 4 hexadecimal characters

dev15 = deviation from ht1 in millimeters, 4 hexadecimal characters
tries = number of tries to deliver BPR data (up to 3)
* = checksum delimiter
checksum = exclusive OR of all characters preceding "*", hexadecimal

Example Message

D$fI 02 tt 18:32:45 ts 18:32:00 3772335 fffdfffafff7fff5fff1ffeeffea00190048ffe1ffddffdaffd8ffd5ffd101* 21

D$F Event Report Mode Hourly Description:

D$F messages are reported on an hourly schedule. They are interspersed with D$f messages while a unit is reporting in Event Mode. 120 samples are reported; 60 previously reported samples provide redundancy and 60 ‘new’ samples are reported in each message.

All D$F data are 1-minute averages of four 15-second samples. The 15-second values used to compute 1-minute averages are ALWAYS: xx:xx:00 xx:xx:15 xx:xx:30 xx:xx45. The 1-minute value time stamp ALWAYS corresponds with xx:xx:00.

NOTE: For D$F messages (and D$3), there is no white-space character between Message Status (C or I) and the tt Event trigger designation and no message sequence numbers.

Message Breakdown

"<cr>D$FC/Itt ttTime ts tsTime height
<cr>dev1 dev2 dev3 … dev24
<cr>dev25 … dev48
<cr>dev49 … dev72
<cr>dev73 … dev96
<cr>dev97 … dev119 tries * checksum"

<cr> = 0x0D
D$F = message ID
C/I = message status; C=Corrupted, I=Intact
tt = Event trigger designation
ttTime = time (UTC) event detected
ts = time stamp designation
tsTime = time (UTC) of first water column height in this message
height = water column height in millimeters
dev1 → dev24 = deviation from height in millimeters, 4 hexadecimal characters
dev25 → dev48 = deviation from height in millimeters, 4 hexadecimal characters
dev49 → dev72 = deviation from height in millimeters, 4 hexadecimal characters
dev73 → dev96 = deviation from height in millimeters, 4 hexadecimal characters
dev97 → dev119 = deviation from height in millimeters, 4 hexadecimal characters
tries = number of tries to deliver BPR data (up to 3)
* = checksum delimiter
checksum = exclusive OR of all characters preceding "*", hexadecimal

Example Message

D$FItt 18:32:45 ts 17:00:00 3772621
fffdfffbfff6fff3fff0ffecffe9ffe6ffe3ffdfffddffd9ffd6ffd3ffcfffccffc9ffc5ffc2ffbfffbdffbaffb7ffb4
ffb1ffaeffabffa9ffa5ffa2ff9effcdfffcff95ff91ff8eff8cff89ff85ff84ff81ff7fff7cff7aff78ff75ff73ff6f
f6cff68ff66ff63ff60ff5eff5bff58ff55ff52ff50ff4dff4aff49ff46ff42ff41ff3dff3bff38ff36ff34ff32ff2f
ff2dff2bff29ff28ff25ff23ff21ff1eff1cff1aff18ff17ff14ff12ff10ff0dff0dff0bff0aff07ff06ff04ff03ff00
fefefefdfefbfef9fef8fef5fef5fef3fef1fef0feeefeeefeedfeeafee9fee8fee6fee4fee3fee2fee1fedffedf01* 3D

Table 1: D$f Event Mode Message Sequence Numbering (same as D$2)

Report time Msg ID First data Last data Data type
T=0=tt D$f 00 -0.75 from tt 0 = tt 15 sec
3 D$f 01 -0.75 3 15 sec
7 D$f 02 -8 7 1 min avg.
15 D$f 03 0 15 1 min avg.
23 D$f 04 8 23 1 min avg.
31 D$f 05 16 31 1 min avg.
39 D$f 06 24 39 1 min avg.
47 D$f 07 32 47 1 min avg.
55 D$f 08 40 55 1 min avg.
63 D$f 09 48 63 1 min avg.
71 D$f 10 56 71 1 min avg.
87 D$f 11 72 87 1 min avg.
103 D$f 12 88 103 1 min avg.
119 D$f 13 104 119 1 min avg.
135 D$f 14 120 135 1 min avg.
151 D$f 15 136 151 1 min avg.
167 D$f 16 152 167 1 min avg.
183 D$f 17 168 183 1 min avg.