Specpr records are fixed format, 1536 bytes/record. Record number counting starts at 0. Binary data are in IEEE format real numbers and non-byte swapped integers (compatiible with all Sun Microsystems, and Hewlett Packard workstations (Intel and some DEC machines are byte swapped relative to Suns and HPs). Each record may contain different information according to the following scheme.
You can get some library of spectra from ftp://ftpext.cr.usgs.gov/pub/cr/co/denver/speclab/pub/spectral.library/splib06.library/
This page hosts a formal specification of SPECtrum Processing Routines Data Format 3/4/88 using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = Specpr.from_file("path/to/local/file.spec")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = Specpr(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.records # => get records
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
from enum import Enum
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class Specpr(KaitaiStruct):
"""Specpr records are fixed format, 1536 bytes/record. Record number
counting starts at 0. Binary data are in IEEE format real numbers
and non-byte swapped integers (compatiible with all Sun
Microsystems, and Hewlett Packard workstations (Intel and some DEC
machines are byte swapped relative to Suns and HPs). Each record may
contain different information according to the following scheme.
You can get some library of spectra from
ftp://ftpext.cr.usgs.gov/pub/cr/co/denver/speclab/pub/spectral.library/splib06.library/
"""
class RecordType(Enum):
data_initial = 0
text_initial = 1
data_continuation = 2
text_continuation = 3
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.records = []
i = 0
while not self._io.is_eof():
self.records.append(Specpr.Record(self._io, self, self._root))
i += 1
class DataInitial(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.ids = Specpr.Identifiers(self._io, self, self._root)
self.iscta = Specpr.CoarseTimestamp(self._io, self, self._root)
self.isctb = Specpr.CoarseTimestamp(self._io, self, self._root)
self.jdatea = self._io.read_s4be()
self.jdateb = self._io.read_s4be()
self.istb = Specpr.CoarseTimestamp(self._io, self, self._root)
self.isra = self._io.read_s4be()
self.isdec = self._io.read_s4be()
self.itchan = self._io.read_s4be()
self.irmas = self._io.read_s4be()
self.revs = self._io.read_s4be()
self.iband = []
for i in range(2):
self.iband.append(self._io.read_s4be())
self.irwav = self._io.read_s4be()
self.irespt = self._io.read_s4be()
self.irecno = self._io.read_s4be()
self.itpntr = self._io.read_s4be()
self.ihist = (KaitaiStream.bytes_strip_right(self._io.read_bytes(60), 32)).decode(u"ascii")
self.mhist = []
for i in range(4):
self.mhist.append((self._io.read_bytes(74)).decode(u"ascii"))
self.nruns = self._io.read_s4be()
self.siangl = Specpr.IllumAngle(self._io, self, self._root)
self.seangl = Specpr.IllumAngle(self._io, self, self._root)
self.sphase = self._io.read_s4be()
self.iwtrns = self._io.read_s4be()
self.itimch = self._io.read_s4be()
self.xnrm = self._io.read_f4be()
self.scatim = self._io.read_f4be()
self.timint = self._io.read_f4be()
self.tempd = self._io.read_f4be()
self.data = []
for i in range(256):
self.data.append(self._io.read_f4be())
@property
def phase_angle_arcsec(self):
"""The phase angle between iangl and eangl in seconds."""
if hasattr(self, '_m_phase_angle_arcsec'):
return self._m_phase_angle_arcsec
self._m_phase_angle_arcsec = (self.sphase / 1500)
return getattr(self, '_m_phase_angle_arcsec', None)
class CoarseTimestamp(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.scaled_seconds = self._io.read_s4be()
@property
def seconds(self):
if hasattr(self, '_m_seconds'):
return self._m_seconds
self._m_seconds = (self.scaled_seconds * 24000)
return getattr(self, '_m_seconds', None)
class Icflag(KaitaiStruct):
"""it is big endian."""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.reserved = self._io.read_bits_int_be(26)
self.isctb_type = self._io.read_bits_int_be(1) != 0
self.iscta_type = self._io.read_bits_int_be(1) != 0
self.coordinate_mode = self._io.read_bits_int_be(1) != 0
self.errors = self._io.read_bits_int_be(1) != 0
self.text = self._io.read_bits_int_be(1) != 0
self.continuation = self._io.read_bits_int_be(1) != 0
@property
def type(self):
if hasattr(self, '_m_type'):
return self._m_type
self._m_type = KaitaiStream.resolve_enum(Specpr.RecordType, ((int(self.text) * 1) + (int(self.continuation) * 2)))
return getattr(self, '_m_type', None)
class DataContinuation(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.cdata = []
for i in range(383):
self.cdata.append(self._io.read_f4be())
class Identifiers(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.ititle = (KaitaiStream.bytes_strip_right(self._io.read_bytes(40), 32)).decode(u"ascii")
self.usernm = (self._io.read_bytes(8)).decode(u"ascii")
class IllumAngle(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.angl = self._io.read_s4be()
@property
def seconds_total(self):
if hasattr(self, '_m_seconds_total'):
return self._m_seconds_total
self._m_seconds_total = self.angl // 6000
return getattr(self, '_m_seconds_total', None)
@property
def minutes_total(self):
if hasattr(self, '_m_minutes_total'):
return self._m_minutes_total
self._m_minutes_total = self.seconds_total // 60
return getattr(self, '_m_minutes_total', None)
@property
def degrees_total(self):
if hasattr(self, '_m_degrees_total'):
return self._m_degrees_total
self._m_degrees_total = self.minutes_total // 60
return getattr(self, '_m_degrees_total', None)
class TextInitial(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.ids = Specpr.Identifiers(self._io, self, self._root)
self.itxtpt = self._io.read_u4be()
self.itxtch = self._io.read_s4be()
self.itext = (self._io.read_bytes(1476)).decode(u"ascii")
class Record(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.icflag = Specpr.Icflag(self._io, self, self._root)
_on = self.icflag.type
if _on == Specpr.RecordType.data_initial:
self._raw_content = self._io.read_bytes((1536 - 4))
_io__raw_content = KaitaiStream(BytesIO(self._raw_content))
self.content = Specpr.DataInitial(_io__raw_content, self, self._root)
elif _on == Specpr.RecordType.data_continuation:
self._raw_content = self._io.read_bytes((1536 - 4))
_io__raw_content = KaitaiStream(BytesIO(self._raw_content))
self.content = Specpr.DataContinuation(_io__raw_content, self, self._root)
elif _on == Specpr.RecordType.text_continuation:
self._raw_content = self._io.read_bytes((1536 - 4))
_io__raw_content = KaitaiStream(BytesIO(self._raw_content))
self.content = Specpr.TextContinuation(_io__raw_content, self, self._root)
elif _on == Specpr.RecordType.text_initial:
self._raw_content = self._io.read_bytes((1536 - 4))
_io__raw_content = KaitaiStream(BytesIO(self._raw_content))
self.content = Specpr.TextInitial(_io__raw_content, self, self._root)
else:
self.content = self._io.read_bytes((1536 - 4))
class TextContinuation(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.tdata = (self._io.read_bytes(1532)).decode(u"ascii")