INTERFACE SPECIFICATIONS
SeaBat 8160
Operator‟s Manual
Page 83
October 6, 2011
Version 5
C.3.7 R Theta Packets
C.3.7.1
Packet Type 0x17
struct R_THETA_DATA
{
char
synch_header[4];
// synch header {0xff, 0xff, 0x00, 0x00}
char
packet_type;
//identifier for packet type (0x17)
char
packet_subtype;
//identifier for packet subtype
unsigned short
latency;
//time from ping to output (milliseconds)
DATA_TIME
data_time;
//time of ping for data packet
unsigned long
ping_number;
//sequential ping number from sonar startup/reset
unsigned long
sonar_id
//least significant four bytes of Ethernet address
unsigned short
sonar_model
//coded model number of sonar
unsigned short
frequency
//sonar frequency in kHz
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 short
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
projector_type;
//bits 0-4 = projector type
//bit 7 = pitch steering (1 = enabled, 2 = disabled)
unsigned char
projector_beam_width
//along track transmit beam width (degrees * 10)
unsigned short
beam_spacing_num;
//receive beam angular spacing numerator
unsigned short
beam_spacing_denom; //cross track receive beam angular spacing
// denominator
//beam width degrees = numerator / denominator
short
projector angle;
//projector pitch steering angle (degrees * 100)
unsigned short
min_range;
//sonar filter settings
unsigned short
max_range;
unsigned short
min_depth;
unsigned short
max_depth;
unsigned char
filtedrs_active;
//range/depth filters active
//bit 0
– range filter (0 = off, 1 = active)
//bit1
– depth filter (0 = off, 1 = active)
unsigned char
flags;
//bit 0
– Roll stabilization flag (0 = off, 1 = on)
unsigned char
spare[2];
//spare field for future growth
short
temperature;
//temperature at Sonar Array (deg C * 10)
short
beam_count;
//number of sets of beam data in packet
unsigned short
range[n];
//range for beam N = beam_count
//range units = sample cells * 4 (“14.2” format)
