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mirror of https://github.com/peterantypas/maiana.git synced 2025-05-15 23:10:11 -07:00
2021-09-09 08:14:28 -07:00

94 lines
2.6 KiB
C++

#include "ais.h"
namespace libais {
Ais9::Ais9(const char *nmea_payload, const size_t pad)
: AisMsg(nmea_payload, pad), alt(0), sog(0.0), position_accuracy(0),
cog(0.0), timestamp(0), alt_sensor(0), spare(0), dte(0), spare2(0),
assigned_mode(0), raim(false), commstate_flag(0), sync_state(0),
slot_timeout_valid(false), slot_timeout(0),
received_stations_valid(false), received_stations(0),
slot_number_valid(false), slot_number(0),
utc_valid(false), utc_hour(0), utc_min(0), utc_spare(0),
slot_offset_valid(false), slot_offset(0),
slot_increment_valid(false), slot_increment(0),
slots_to_allocate_valid(false), slots_to_allocate(0),
keep_flag_valid(false), keep_flag(false) {
if (!CheckStatus()) {
return;
}
if (pad != 0 || num_chars != 28) {
status = AIS_ERR_BAD_BIT_COUNT;
return;
}
assert(message_id == 9);
bits.SeekTo(38);
alt = bits.ToUnsignedInt(38, 12);
sog = bits.ToUnsignedInt(50, 10); // Type 9: Speed over ground is in knots.
position_accuracy = bits[60];
position = bits.ToAisPoint(61, 55);
cog = bits.ToUnsignedInt(116, 12) / 10.;
timestamp = bits.ToUnsignedInt(128, 6);
alt_sensor = bits[134];
spare = bits.ToUnsignedInt(135, 7);
dte = bits[142];
spare2 = bits.ToUnsignedInt(143, 3);
assigned_mode = bits[146];
raim = bits[147];
commstate_flag = bits[148]; // 0 SOTDMA, 1 ITDMA
sync_state = bits.ToUnsignedInt(149, 2);
if (commstate_flag == 0) {
// SOTDMA
slot_timeout = bits.ToUnsignedInt(151, 3);
slot_timeout_valid = true;
switch (slot_timeout) {
case 0:
slot_offset = bits.ToUnsignedInt(154, 14);
slot_offset_valid = true;
break;
case 1:
utc_hour = bits.ToUnsignedInt(154, 5);
utc_min = bits.ToUnsignedInt(159, 7);
utc_spare = bits.ToUnsignedInt(166, 2);
utc_valid = true;
break;
case 2: // FALLTHROUGH
case 4: // FALLTHROUGH
case 6:
slot_number = bits.ToUnsignedInt(154, 14);
slot_number_valid = true;
break;
case 3: // FALLTHROUGH
case 5: // FALLTHROUGH
case 7:
received_stations = bits.ToUnsignedInt(154, 14);
received_stations_valid = true;
break;
default:
assert(false);
}
} else {
// ITDMA
slot_increment = bits.ToUnsignedInt(151, 13);
slot_increment_valid = true;
slots_to_allocate = bits.ToUnsignedInt(164, 3);
slots_to_allocate_valid = true;
keep_flag = bits[167];
keep_flag_valid = true;
}
assert(bits.GetRemaining() == 0);
status = AIS_OK;
}
} // namespace libais