INTERFACE SPECIFICATIONS
SeaBat 8160
Operator‟s Manual
Page 86
October 6, 2011
Version 5
The data from the sonar will not be slant range corrected. Determining the
altitude of the sonar array and performing slant ranged correction is the
responsibility of the Data Acquisition System.
The sonar imagery data will not be compensated for changes in power and gain.
C.3.9.1
Sidescan Packet
struct SIDESCAN_IMAGE
{
char
STX;
//start character (0x02)
char
id;
//packet id (0x48)
unsigned short
packet_size;
//size of packet
– next field through last
//Amplitude value
unsigned long
ping_no
//sequential ping number since sonar
//power-up / reset
DATA_TIME
data_time;
//time of ping for data packet
unsigned short
total_samples;
//total number of amplitude samples for ping
unsigned short
ping_packet;
//sequence number
– (0 to n)
unsigned short
velocity;
//programmed sound velocity (LSB = 1m/sec)
unsigned short
sample_rate;
//A/D sample rate (samples per second)
unsigned short
ping_rate;
//ping rate (pings per second *1000)
unsigned short
range set;
//range setting for SeaBat (meters)
unsigned short
power;
//power setting for SeaBat
unsigned short
gain;
//gain setting for SeaBat
//bits
0-6
gain (1 - 45)
//bit
14
(0 = fixed, 1 = tvg)
//bit
15
(0 = manual, 1 = auto)
unsigned char
pulse_width;
//transmit pulse width (microseconds)
unsigned char
tvg_spread;
//spreading coefficient for tvg *4
//valid values = 0 to 240
//(0.0 to 60.0 in 0.25 steps)
unsigned char
tvg_absorp;
absorption coefficient for tvg
unsigned char
flags;
//bit 0
– Roll stabilization flag (0 = off, 1 = on)
unsigned short
spare1(2)
//more spares
short
projector;
//projector setting
unsigned short
sample_count;
//number of amplitude samples in packet
unsigned short
amplitude[n]
//amplitude data N = sample_count
//12 bit amplitude stored in 12 most
//significant bits
unsigned char
spare2;
//spare to align ETX and checksum
char
ETX;
//packet end character (0x03)
unsigned short
checksum;
//checksum for data packet
};
C.3.10 Snippet Data Format
The sonar processor outputs snippet data via UDP/IP (base port + 6). Each ping
generates a burst of Ethernet packets containing one SNP0 header followed by
BeamCnt Snippets (one snippet per beam). Each snippet consists of one or more
fragments. The sonar processor packs fragments into large, efficient Ethernet
