public GRIB2DataRepresentationSection(FileStream fs)
{
_sectionHeader = new GRIB2SectionHeader(fs);
_dataPoints = GribNumberHelper.Int4(fs);
_dataTemplate = (int)GribNumberHelper.Uint2(fs);
SetOtherAttributeByDataTemplateNo(fs);
}
private void SetOtherAttributeByDataTemplateNo(FileStream fs)
{
_referenceValue = GribNumberHelper.IEEEfloat4(fs);
_binaryScaleFactor = GribNumberHelper.Int2(fs);
_decimalScaleFactor = GribNumberHelper.Int2(fs);
_numberOfBits = fs.ReadByte();
_originalType = fs.ReadByte();
switch (_dataTemplate)
{
case 0: //0 - Grid point data - simple packing
case 1: //1 - Matrix values - simple packing
{
break;
}
case 2:
case 3:
{
_splittingMethod = fs.ReadByte();
// octet 23
_missingValueManagement = fs.ReadByte();
// octet 24 - 27
_primaryMissingValue = GribNumberHelper.IEEEfloat4(fs);
// octet 28 - 31
_secondaryMissingValue = GribNumberHelper.IEEEfloat4(fs);
// octet 32 - 35
_numberOfGroups = GribNumberHelper.Int4(fs);
// octet 36
_referenceGroupWidths = fs.ReadByte();
// octet 37
_bitsGroupWidths = fs.ReadByte();
// according to documentation subtract referenceGroupWidths
_bitsGroupWidths = _bitsGroupWidths - _referenceGroupWidths;
// octet 38 - 41
_referenceGroupLength = GribNumberHelper.Int4(fs);
// octet 42
_lengthIncrement = fs.ReadByte();
// octet 43 - 46
_lengthLastGroup = GribNumberHelper.Int4(fs);
// octet 47
_bitsScaledGroupLength = fs.ReadByte();
if (_dataTemplate == 3)
{
// case 3 // complex packing & spatial differencing
_orderSpatial = fs.ReadByte();
_descriptorSpatial = fs.ReadByte();
}
break;
}
case 4:
case 4000:
{
_compressionMethod = fs.ReadByte();
_compressionRatio = fs.ReadByte();
break;
}
}
}
public GRIB2DataRepresentationSection(FileStream fs)
{
long position = fs.Position;
_sectionHeader = new GRIB2SectionHeader(fs);
_dataPoints = GribNumberHelper.Int4(fs);
_dataTemplate = (int)GribNumberHelper.Uint2(fs);
SetOtherAttributeByDataTemplateNo(fs);
fs.Seek(position + _sectionHeader.SectionLength, SeekOrigin.Begin);
}
private float _dstart; //Dstart ― offset from origin to inner bound
public GRIB2GridDefinitionSection(FileStream fs)
{
_sectionHeader = new GRIB2SectionHeader(fs);
_source = fs.ReadByte();
_pointsNumber = GribNumberHelper.Int4(fs);
_olon = fs.ReadByte();
_iolon = fs.ReadByte();
_gridTemplateNo = GribNumberHelper.Int2(fs);
_gridName = GetGridNameByGridNo();
SetAttributeByGridTemplateNo(fs);
}
private float _dstart; //Dstart ― offset from origin to inner bound
public GRIB2GridDefinitionSection(FileStream fs)
{
long position = fs.Position;
_sectionHeader = new GRIB2SectionHeader(fs);
_source = fs.ReadByte();
_pointsNumber = GribNumberHelper.Int4(fs);
_olon = fs.ReadByte();
_iolon = fs.ReadByte();
_gridTemplateNo = GribNumberHelper.Int2(fs);
_gridName = GetGridNameByGridNo();
SetAttributeByGridTemplateNo(fs);
fs.Seek(position + _sectionHeader.SectionLength, SeekOrigin.Begin);
}
private void ReadToDataProvider()
{
if (string.IsNullOrEmpty(_fileName) || !File.Exists(_fileName))
{
return;
}
long gdsOffset = 0; // GDS offset from start of file
bool startAtHeader = true; // otherwise skip to GDS
bool processGDS = true;
FileStream _fs = new FileStream(_fileName, FileMode.Open, FileAccess.Read);
GRIB2IndicatorSection iSection = null;
GRIB2IdentificationSection idSection = null;
GRIB2LocalUseSection lus = null;
GRIB2GridDefinitionSection gds = null;
while (_fs.Position < _fs.Length)
{
if (startAtHeader)
{
// begining of record
if (!SeekHeader(_fs, _fs.Length))
{
goto setAttributes;
}
// Read Section 0 Indicator Section
iSection = new GRIB2IndicatorSection(_fs); // section 0
_discipline = iSection.Displine;
// Read other Sections
idSection = new GRIB2IdentificationSection(_fs); // Section 1
_referenceTime = idSection.ReferenceTime;
} // end startAtHeader
if (processGDS)
{
// check for Local Use Section 2
lus = new GRIB2LocalUseSection(_fs);
// obtain GDS offset in the file for this record
gdsOffset = _fs.Position;
// Section 3
gds = new GRIB2GridDefinitionSection(_fs);
}
// obtain PDS offset in the file for this record
long pdsOffset = _fs.Position;
IGRIB2ProductDefinitionSection pds = new GRIB2ProductDefinitionSection(_fs); // Section 4
IGRIB2DataRepresentationSection drs = new GRIB2DataRepresentationSection(_fs); // Section 5
IGribBitMapSection bms = new GRIB2BitMapSection(_fs, gds.PointsNumber); // Section 6
long dataOffset = _fs.Position + 5;
GRIB2DataSection ds = new GRIB2DataSection(_fs, dataOffset); //Section 7
GRIB2Record record = new GRIB2Record(iSection.Displine, gds, pds, drs, bms, ds, gdsOffset, pdsOffset, dataOffset);
_records.Add(record);
_parameterList.Add(record.ParameterName);
if (_fs.Position > _fs.Length)
{
_fs.Seek(0, System.IO.SeekOrigin.Begin);
goto setAttributes;
}
int ending = GribNumberHelper.Int4(_fs);
if (ending == 926365495)
{
// record ending string 7777 as a number
startAtHeader = true;
processGDS = true;
}
else
{
//_fs.Seek(4, SeekOrigin.Current);
int section = _fs.ReadByte(); // check if GDS or PDS section, 3 or 4
//reset back to begining of section
_fs.Seek(_fs.Position - 5, System.IO.SeekOrigin.Begin);
if (section == 3)
{
startAtHeader = false;
processGDS = true;
}
else if (section == 4)
{
startAtHeader = false;
processGDS = false;
}
else
{
GribEndSection es = new GribEndSection(_fs);
if (es.IsEndFound)
{
startAtHeader = true;
processGDS = true;
}
else
{
goto setAttributes;
}
}
}
}
setAttributes:
SetAttribute(gds);
}
private void SetAttributeByGridTemplateNo(FileStream fs)
{
int scaleFactorRadius, scaleDvalueRadius, scaleFactorMajor, scaleDvalueMajor,
scaleFactorMinor, scaleDvalueMinor;
float ratio;
if ((_gridTemplateNo >= 50 && _gridTemplateNo <= 53) || _gridTemplateNo == 100 || _gridTemplateNo == 120)
{
if (_gridTemplateNo >= 50 && _gridTemplateNo <= 53)
{
_j = GribNumberHelper.IEEEfloat4(fs);
_k = GribNumberHelper.IEEEfloat4(fs);
_m = GribNumberHelper.IEEEfloat4(fs);
_method = fs.ReadByte();
_mode = fs.ReadByte();
if (_gridTemplateNo == 51)
{
_spLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_spLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_rotationAngle = GribNumberHelper.IEEEfloat4(fs);
}
else if (_gridTemplateNo == 52)
{
_poleLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_poleLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_factor = GribNumberHelper.Int4(fs);
}
else if (_gridTemplateNo == 53)
{
_spLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_spLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_rotationAngle = GribNumberHelper.IEEEfloat4(fs);
_poleLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_poleLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_factor = GribNumberHelper.Int4(fs);
}
}
else if (_gridTemplateNo == 100)
{
_n2 = fs.ReadByte();
_n3 = fs.ReadByte();
_ni = GribNumberHelper.Int2(fs);
_nd = fs.ReadByte();
_poleLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_poleLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_lonofcenter = GribNumberHelper.Int4(fs);
_position = fs.ReadByte();
_order = fs.ReadByte();
_scanMode = fs.ReadByte();
_nt = GribNumberHelper.Int4(fs);
}
else
{
_nb = GribNumberHelper.Int4(fs);
_nr = GribNumberHelper.Int4(fs);
_latFirstPoint = GribNumberHelper.Int4(fs);
_lonFirstPoint = GribNumberHelper.Int4(fs);
_dx = GribNumberHelper.Int4(fs);
_dstart = GribNumberHelper.IEEEfloat4(fs);
_scanMode = fs.ReadByte();
}
}
else
{
_shape = fs.ReadByte();
scaleFactorRadius = fs.ReadByte();
scaleDvalueRadius = GribNumberHelper.Int4(fs);
scaleFactorMajor = fs.ReadByte();
scaleDvalueMajor = GribNumberHelper.Int4(fs);
scaleFactorMinor = fs.ReadByte();
scaleDvalueMinor = GribNumberHelper.Int4(fs);
_nx = GribNumberHelper.Int4(fs);
_ny = GribNumberHelper.Int4(fs);
switch (_gridTemplateNo)
{
// Latitude/Longitude Grid
case 0:
case 1:
case 2:
case 3:
{
_angle = GribNumberHelper.Int4(fs);
_subDivisionsAngle = GribNumberHelper.Int4(fs);
if (_angle == 0)
{
ratio = TenToNegSix;
}
else
{
ratio = _angle / _subDivisionsAngle;
}
_latFirstPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_lonFirstPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_resolutionFlag = fs.ReadByte();
_latEndPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_lonEndPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_dx = (float)(GribNumberHelper.Int4(fs) * ratio);
_dy = (float)(GribNumberHelper.Int4(fs) * ratio);
_scanMode = fs.ReadByte();
// 1, 2, and 3 needs checked
if (_gridTemplateNo == 1)
{
//Rotated Latitude/longitude
_spLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_spLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_rotationAngle = GribNumberHelper.IEEEfloat4(fs);
}
else if (_gridTemplateNo == 2)
{
//Stretched Latitude/longitude
_poleLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_poleLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_factor = GribNumberHelper.Int4(fs);
}
else if (_gridTemplateNo == 3)
{
//Stretched and Rotated Latitude/longitude
_spLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_spLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_rotationAngle = GribNumberHelper.IEEEfloat4(fs);
_poleLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_poleLon = GribNumberHelper.Int4(fs) * TenToNegSix;
_factor = GribNumberHelper.Int4(fs);
}
break;
}
case 10: // Mercator
{
_latFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_lonFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_resolutionFlag = fs.ReadByte();
_latD = GribNumberHelper.Int4(fs) * TenToNegSix;
_latEndPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_lonEndPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_scanMode = fs.ReadByte();
_angle = GribNumberHelper.Int4(fs);
_dx = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_dy = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
break;
}
case 20: // Polar stereographic projection
{
_latFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_lonFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_resolutionFlag = fs.ReadByte();
_latD = GribNumberHelper.Int4(fs) * TenToNegSix;
_lov = GribNumberHelper.Int4(fs) * TenToNegSix;
_dx = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_dy = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_projectionCenter = fs.ReadByte();
_scanMode = fs.ReadByte();
break;
}
case 30: // Lambert Conformal
{
_latFirstPoint = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_lonFirstPoint = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_resolutionFlag = fs.ReadByte();
_latD = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_lov = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_dx = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_dy = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_projectionCenter = fs.ReadByte();
_scanMode = fs.ReadByte();
_latin1 = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_latin2 = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_spLat = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
_spLon = (float)(GribNumberHelper.Int4(fs) * TenToNegSix);
break;
}
case 31: // Albers Equal Area
{
_latFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_lonFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_resolutionFlag = fs.ReadByte();
_latD = GribNumberHelper.Int4(fs) * TenToNegSix;
_lov = GribNumberHelper.Int4(fs) * TenToNegSix;
_dx = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_dy = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_projectionCenter = fs.ReadByte();
_scanMode = fs.ReadByte();
_latin1 = GribNumberHelper.Int4(fs) * TenToNegSix;
_latin2 = GribNumberHelper.Int4(fs) * TenToNegSix;
_spLat = GribNumberHelper.Int4(fs) * TenToNegSix;
_spLon = GribNumberHelper.Int4(fs) * TenToNegSix;
break;
}
case 40:
case 41:
case 42:
case 43: // Gaussian latitude/longitude
{
_angle = GribNumberHelper.Int4(fs);
_subDivisionsAngle = GribNumberHelper.Int4(fs);
if (_angle == 0)
{
ratio = TenToNegSix;
}
else
{
ratio = _angle / _subDivisionsAngle;
}
_latFirstPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_lonFirstPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_resolutionFlag = fs.ReadByte();
_latEndPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_lonEndPoint = (float)(GribNumberHelper.Int4(fs) * ratio);
_dx = (float)(GribNumberHelper.Int4(fs) * ratio);
_paralellNumber = fs.ReadByte();
_scanMode = fs.ReadByte();
if (_gridTemplateNo == 41)
{
_spLat = GribNumberHelper.Int4(fs) * ratio;
_spLon = GribNumberHelper.Int4(fs) * ratio;
_rotationAngle = GribNumberHelper.IEEEfloat4(fs);
}
else if (_gridTemplateNo == 42)
{
_poleLat = GribNumberHelper.Int4(fs) * ratio;
_poleLon = GribNumberHelper.Int4(fs) * ratio;
_factor = GribNumberHelper.Int4(fs);
}
else if (_gridTemplateNo == 43)
{
_spLat = GribNumberHelper.Int4(fs) * ratio;
_spLon = GribNumberHelper.Int4(fs) * ratio;
_rotationAngle = GribNumberHelper.IEEEfloat4(fs);
_poleLat = GribNumberHelper.Int4(fs) * ratio;
_poleLon = GribNumberHelper.Int4(fs) * ratio;
_factor = GribNumberHelper.Int4(fs);
}
break;
}
case 90: // Space view perspective or orthographic
{
_lap = GribNumberHelper.Int4(fs);
_lop = GribNumberHelper.Int4(fs);
_resolutionFlag = fs.ReadByte();
_dx = GribNumberHelper.Int4(fs);
_dy = GribNumberHelper.Int4(fs);
_xp = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_yp = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_scanMode = fs.ReadByte();
_angle = GribNumberHelper.Int4(fs);
_altitude = GribNumberHelper.Int4(fs) * 1000000;
_xo = GribNumberHelper.Int4(fs);
_yo = GribNumberHelper.Int4(fs);
break;
}
case 110: // Equatorial azimuthal equidistant projection
{
_latFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_lonFirstPoint = GribNumberHelper.Int4(fs) * TenToNegSix;
_resolutionFlag = fs.ReadByte();
_dx = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_dy = (float)(GribNumberHelper.Int4(fs) * TenToNegThree);
_projectionCenter = fs.ReadByte();
_scanMode = fs.ReadByte();
break;
}
}
}
}
public GRIB2SectionHeader(FileStream fs)
{
_sectionLength = GribNumberHelper.Int4(fs);
_sectionNo = fs.ReadByte();
}
private void SetOtherAttributeByProductDefinition(FileStream fs)
{
// octet 10
_parameterCategory = fs.ReadByte();
// octet 11
_parameterNumber = fs.ReadByte();
switch (_productDefinitionTemplateNo)
{
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
{
// octet 12
_typeGenProcess = fs.ReadByte();
// octet 13
_backGenProcess = fs.ReadByte();
// octet 14
_analysisGenProcess = fs.ReadByte();
// octet 15-16
_hoursAfter = GribNumberHelper.Int2(fs);
// octet 17
_minutesAfter = fs.ReadByte();
// octet 18
_timeRangeUnit = fs.ReadByte();
// octet 19-22
_forecastTime = GribNumberHelper.Int4(fs);
// octet 23
_typeFirstFixedSurface = fs.ReadByte();
// octet 24
int scaleFirstFixedSurface = fs.ReadByte();
// octet 25-28
int valueFirstFixedSurface = GribNumberHelper.Int4(fs);
_firstFixedSurfaceValue = (float)((scaleFirstFixedSurface == 0 || valueFirstFixedSurface == 0) ? valueFirstFixedSurface : System.Math.Pow(valueFirstFixedSurface, -scaleFirstFixedSurface));
// octet 29
_typeSecondFixedSurface = fs.ReadByte();
// octet 30
int scaleSecondFixedSurface = fs.ReadByte();
// octet 31-34
int valueSecondFixedSurface = GribNumberHelper.Int4(fs);
_secondFixedSurfaceValue = (float)((scaleSecondFixedSurface == 0 || valueSecondFixedSurface == 0) ? valueSecondFixedSurface : System.Math.Pow(valueSecondFixedSurface, -scaleSecondFixedSurface));
if (_productDefinitionTemplateNo == 8)
{
// 35-41 bytes
int year = GribNumberHelper.Int2(fs);
int month = (fs.ReadByte()) - 1;
int day = fs.ReadByte();
int hour = fs.ReadByte();
int minute = fs.ReadByte();
int second = fs.ReadByte();
// 42 - 46
int timeRanges = fs.ReadByte();
int missingDataValues = GribNumberHelper.Int4(fs);
// 47 - 48
int outmostTimeRange = fs.ReadByte();
int missing = fs.ReadByte();
// 49 - 53
int statisticalProcess = fs.ReadByte();
int timeIncrement = GribNumberHelper.Int4(fs);
// 54 - 58
int indicatorTR = fs.ReadByte();
int lengthTR = GribNumberHelper.Int4(fs);
}
break;
}
case 20:
{
_typeGenProcess = fs.ReadByte();
// octet 13
_backGenProcess = fs.ReadByte();
// octet 14
_analysisGenProcess = fs.ReadByte();
// octet 15-16
_hoursAfter = GribNumberHelper.Int2(fs);
// octet 17
_minutesAfter = fs.ReadByte();
// octet 18
_timeRangeUnit = fs.ReadByte();
// octet 19-22
_forecastTime = GribNumberHelper.Int4(fs);
break;
}
case 30:
{
// octet 12
_typeGenProcess = fs.ReadByte();
// octet 13
_backGenProcess = fs.ReadByte();
// octet 14
_nb = fs.ReadByte();
fs.Seek(10 * _nb, SeekOrigin.Current);
break;
}
case 254:
{
break;
}
}
}
