beautypg.com

Triton Isis User Manual

Page 126

background image

June 2004 Isis® Sonar User's Manual, Volume 2

116

Table G-2. SeaBird’s CTD SEG-Y values in 2nd channel’s binary trace header

long

Conductivity

bytes 200-203 Conductivity, Siemens per meter times 100000

long

Temperature

bytes 204-207 Temperature in degrees C, times 1000

long

Pressure

bytes 208-211 Pressure in psia, times 1000

long

SoundVelocity

bytes 212-215 Computed speed of sound, times 100

See the file SEGYFMT.H for more info on how Isis uses the SEG-Y data format.

4. If saving in Q-MIPS format version 1.51 or later, the values are saved as follows:

Table G-3. SeaBird’s CTD SEG-Y format values saved in Q-MIPS footer record

float Conductivity

[Q] computed Conductivity in Siemens per meter

float waterTemperature [b] computed Water Temperature in C

float Pressure

[0] computed water pressure in psia

WORD soundVelocity

[v] computed sound velocity in m/s times 30

WORD Turbidity

[|] percent of light times 10000

See the file QMIPSFMT.H for the placement of these variables. Note that the raw
(frequency) values from the SeaBird CTD are not saved in the Q-MIPS file format;
only the computed (result) values are saved.

5. Towfish depth (computed in step 1.) is displayed in the Depth field in the

Telemetry area in the Parameter Display window.

6. If the Sensors display is open, then the following information is displayed (note

that these are the exact values stored on disk):

Appendix G: How Isis Processes CTD Data