Most of these numbers also appear in the Processed SAM Data window in
ALOHA
, along with
some additional checksum numbers, but without the labels. The raw data is delivered in metric
units (millibars, m/s, °C), whereas the processed data is converted to standard English units
(inches, MPH, °F).
Two checksums are performed to ensure the message was sent correctly. The computer adds up
the ASCII value of the data line (each character, such as numbers, letters, and punctuation, have a
numeric value universal to all computers) to make sure the computer received the same number
that the WEATHERPAK M transmitted.
4.1
ALOHA
data line interpretation
The data line fields are as follows:
ID, MW, MD, ST, AT, SI, DI, TI, BV, CKSUM1, BP, RH, CKSUM2
ID –
MW –
MD –
ST –
AT –
SI –
DI –
TI –
BV –
WEATHERPAK
M
unique
identification
number
5
minute
averaged
wind
speed
in
met
re
s
per
second
5
minute
averaged
wind
direction
in
degrees
Stability
class
in
degrees
5
minute
averaged
air
temperature
in
degrees
Celsius
Instantaneous
wind
speed
in
met
re
s
per
second
Instantaneous
wind
direction
in
degrees
Instantaneous
air
temperature
in
degrees
Celsius
Battery
voltage
in
volts
CKSUM1 –
First checksum
BP –
Barometric pressure in millibars
RH –
Relative humidity in percent
CKSUM2 –
Second checksum
WEATHERPAK M
28
