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 set_ext_header_seg(self):
''' SEG-Y rev 01 extended header '''
ext = {}
self.extended_header = segy_h.Seg()
# Same as lino from reel header
try:
ext['Inn'] = int(self.sort_t['array_name_s'])
except (ValueError, TypeError):
ext['Inn'] = 1
# Shot point number
try:
ext['Spn'] = int(self.event_t['id_s'])
except ValueError:
ext['Spn'] = 0
# Spn scaler
ext['Scal'] = 1
# Trace value measurement units
ext['Tvmu'] = 0
# Size of shot
ext['Smsmant'] = int(self.event_t['size/value_d'])
ext['Smsexp'] = 1
ext['Smu'] = 0
# Number of samples
ext['num_samps'] = self.length_points
# Sample interval in microseconds
ext['samp_rate'] = int((1.0 / self.sample_rate) * 1000000.0)
return ext
def set_ext_header_seg(self):
''' SEG-Y rev 01 extended header '''
ext = {}
self.extended_header = segy_h.Seg()
# Same as lino from reel header
try:
ext['Inn'] = int(self.sort_t['array_name_s'])
except (ValueError, TypeError):
ext['Inn'] = 1
try:
# Shot point number
ext['Spn'] = int(self.event_t['id_s'])
# Size of shot
ext['Smsmant'] = int(self.event_t['size/value_d'])
except BaseException:
pass
# Spn scaler
ext['Scal'] = 1
# Trace value measurement units
ext['Tvmu'] = 0
ext['Smsexp'] = 1
ext['Smu'] = 0
# 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)
# Trace start usecs
ext['start_usec'] = u_secs
# Shot usecs
ext['shot_us'] = self.event_t['time/micro_seconds_i']
return ext
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)
