def read_extended_header (self) :
ret = {}
buf = self.read_buf (60)
e = segy_h.Seg (self.endianess)
keys = segy_h.Seg ().__keys__
if self.ext_hdr_type == 'U' :
e = segy_h.Menlo (self.endianess)
keys = segy_h.Menlo ().__keys__
elif self.ext_hdr_type == 'S' :
e = segy_h.Seg (self.endianess)
keys = segy_h.Seg ().__keys__
elif self.ext_hdr_type == 'P' :
e = segy_h.Passcal (self.endianess)
keys = segy_h.Passcal ().__keys__
elif self.ext_hdr_type == 'I' :
e = segy_h.Sioseis (self.endianess)
keys = segy_h.Sioseis ().__keys__
elif self.ext_hdr_type == 'N' :
e = segy_h.iNova (self.endianess)
keys = segy_h.iNova ().__keys__
container = e.parse (buf)
for k in keys :
what = "container.{0}".format (k)
ret[k] = eval (what)
return ret
def print_extended_header(container):
if TYPE == 'U':
keys = segy_h.Menlo().__keys__
elif TYPE == 'S':
keys = segy_h.Seg().__keys__
elif TYPE == 'P':
keys = segy_h.Passcal().__keys__
elif TYPE == 'I':
keys = segy_h.Sioseis().__keys__
elif TYPE == 'N':
keys = segy_h.iNova().__keys__
else:
return None
tt = 180
print "---------- Extended Header ----------"
for k in keys:
what = "container.{0}".format(k)
try:
if tt == 9999: raise
s = SIZEOF[k] / 8
if s < 1: raise
foffset = "{0:<3} - {1:>3}".format(tt, tt + s - 1)
tt += s
except:
tt = 9999
foffset = "{0:<3} - {1:>3}".format('_', '_')
print "{2} {0:<20}\t---\t{1}".format(k, eval(what), foffset)
def read_extended_header():
buf = FH.read(60)
if TYPE == 'U':
e = segy_h.Menlo(ENDIAN)
elif TYPE == 'S':
e = segy_h.Seg(ENDIAN)
elif TYPE == 'P':
e = segy_h.Passcal(ENDIAN)
elif TYPE == 'I':
e = segy_h.Sioseis(ENDIAN)
elif TYPE == 'N':
e = segy_h.iNova(ENDIAN)
else:
return None
return e.parse(buf)
def set_ext_header_menlo(self):
''' Use USGS Menlo's idea of extended trace header '''
ext = {}
self.extended_header = segy_h.Menlo()
# Start of trace
cor_low, cor_high, sort_start_time = self._cor()
corrected_start_time = self.cut_start_epoch + (cor_low / 1000.0)
u_secs = int(math.modf(corrected_start_time)[0] * 1000000.0)
ext['start_usec'] = u_secs
# Shot size in Kg
try:
if self.event_t['size/units_s'][0] == 'k' or self.event_t[
'size/units_s'][0] == 'K':
ext['shot_size'] = self.event_t['size/value_d']
except:
pass
# Shot time
try:
ttuple = time.gmtime(float(self.event_t['time/epoch_l']))
ext['shot_year'] = ttuple[0]
ext['shot_doy'] = ttuple[7]
ext['shot_hour'] = ttuple[3]
ext['shot_minute'] = ttuple[4]
ext['shot_second'] = ttuple[5]
ext['shot_us'] = self.event_t['time/micro_seconds_i']
except:
pass
# Always set to 0
ext['si_override'] = 0
# Azimuth and inclination, set to 0?
ext['sensor_azimuth'] = 0
ext['sensor_inclination'] = 0
# Linear moveout static x/v ms
ext['lmo_ms'] = 0
# LMO flag, 1 -> n
ext['lmo_flag'] = 1
# Inst type, 16 == texan
if self.array_t['das/model_s'].find('130') != -1:
ext['inst_type'] = 13 # RT-130
else:
ext['inst_type'] = 16 # texan
# Always set to 0
ext['correction'] = 0
# Uphole azimuth set to zero
ext['azimuth'] = 0
# Sensor type
if self.array_t['sensor/model_s'].find('28') != -1:
ext['sensor_type'] = 1 # L28
elif self.array_t['sensor/model_s'].find('22') != -1:
ext['sensor_type'] = 2 # L22
elif self.array_t['sensor/model_s'].find('4') != -1:
ext['sensor_type'] = 4 # L4
else:
ext['sensor_type'] = 99 # Don't know, don't care
# Sensor sn
try:
ext['sensor_sn'] = int(self.array_t['sensor/serial_number_s'])
except:
pass
# DAS sn
try:
ext['das_sn'] = int(self.array_t['das/serial_number_s'])
except ValueError:
try:
ext['das_sn'] = 0xFFFF & int(
self.array_t['das/serial_number_s'], 16)
except ValueError:
pass
# 16 free bits
try:
ext['empty1'] = self.array_t['channel_number_i']
except:
pass
# Number of samples
ext['samples'] = self.length_points
# 32 free bits
try:
ext['empty2'] = int(self.array_t['description_s'])
except:
pass
# clock correction
try:
ext['clock_drift'] = self._cor()[0]
if ext['clock_drift'] > MAX_16 or ext['clock_drift'] < -MAX_16:
ext['clock_drift'] = int(MAX_16)
except:
pass
# 16 free bits
try:
ext['empty3'] = int(self.event_t['description_s'])
except:
pass
return ext