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E.7.3 the image structure, E.7.4 telemetry structure – Triton Isis User Manual

Page 112

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

102

ContactGroundRange

566 FLOAT

Ground range to the contact

unassigned[2]

568 CHAR

Unused

InternalFileName[248]

816 CHAR

Internal use (passing
.CON/.TGT file name from
Target to Isis)

FishPitch

820 FLOAT

Pitch in degrees (positive =
nose up)

FishRoll

824 FLOAT

Roll in degrees (positive = roll to
stbd)

E.7.3

The Image Structure

Bitmap bits (BitmapWidth • BitmapHeight • BitsPerPixel/8) bytes. Each 8-bit
byte (0…255 for 8-bit data, -32768… +32767 for 16-bit data) is related to
sonar input voltage linearly from 0… +5 volts or –5… +5 volts, respectively.
A zero is always a low return, and the more negative or positive a value
gets, the stronger the acoustic echo.

E.7.4 Telemetry

Structure

Target also uses a structure called Telemetry. Shown in Table E-8, the
structure keeps track of the telemetry information for each ping. The number
of pings is equal to the height. The total number of bytes for this entity is
BitmapHeight * sizeof(telemetry). With this data, Target has detailed
information about every pixel in the image.


Don't change the size of this structure —
or else you won't be able to play back old contacts!











Appendix E: Using the Target Utility