public string[] Decode(byte[] DataBlockBuffer, string Time, out int NumOfMessagesDecoded)
{
// Define output data buffer
string[] DataOut = new string[1000];
// Determine the size of the datablock
int LengthOfDataBlockInBytes = DataBlockBuffer.Length;
// Index into the array of record strings
int DataOutIndex = 0;
// Reset buffer indexes
CurrentDataBufferOctalIndex = 0;
int DataBufferIndexForThisExtraction = 0;
// SIC/SAC Indexes
int SIC_Index = 0;
int SAC_Index = 0;
// Save off SIC/SAC and time in the case they are not present
// in each message. Some implementation have it only in the first record
int SIC = 0;
int SAC = 0;
// Lenght of the current record's FSPECs
int FSPEC_Length = 0;
// The four possible FSPEC octets
BitVector32 FourFSPECOctets = new BitVector32();
while ((DataBufferIndexForThisExtraction) < LengthOfDataBlockInBytes)
{
// Assume that there will be no more than 300 bytes in one record
byte[] LocalSingleRecordBuffer = new byte[3000];
Array.Copy(DataBlockBuffer, DataBufferIndexForThisExtraction, LocalSingleRecordBuffer, 0, (LengthOfDataBlockInBytes - DataBufferIndexForThisExtraction));
// Get all four data words, but use only the number specifed
// by the length of FSPEC words
FourFSPECOctets = ASTERIX.GetFourFSPECOctets(LocalSingleRecordBuffer);
// Determine Length of FSPEC fields in bytes
FSPEC_Length = ASTERIX.DetermineLenghtOfFSPEC(LocalSingleRecordBuffer);
// Check wether 010 is present
if (FourFSPECOctets[Bit_Ops.Bit7] == true)
{
// Determine SIC/SAC Index
SIC_Index = FSPEC_Length;
SAC_Index = SIC_Index + 1;
// Extract SIC/SAC Indexes.
DataOut[DataOutIndex] = LocalSingleRecordBuffer[SIC_Index].ToString() + '/' + LocalSingleRecordBuffer[SAC_Index].ToString();
// Save off data for other records
SIC = LocalSingleRecordBuffer[SIC_Index];
SAC = LocalSingleRecordBuffer[SAC_Index];
// Save of the current data buffer index so it can be used by
// Decoder
CurrentDataBufferOctalIndex = SAC_Index + 1;
}
else
{
CurrentDataBufferOctalIndex = FSPEC_Length;
// Extract SIC/SAC Indexes.
DataOut[DataOutIndex] = SIC.ToString() + '/' + SAC.ToString();
}
///////////////////////////////////////////////////////////////////////////
// Populate the current SIC/SAC and Time stamp for this meesage
//
I048DataItems[ItemIDToIndex("010")].value =
new ASTERIX.SIC_SAC_Time(SIC, SAC, ASTERIX.TimeOfReception);
Reset_Currently_Present_Flags();
// Loop for each FSPEC and determine what data item is present
for (int FSPEC_Index = 1; FSPEC_Index <= FSPEC_Length; FSPEC_Index++)
{
switch (FSPEC_Index)
{
case 1:
// 010 Data Source Identifier
if (FourFSPECOctets[Bit_Ops.Bit7] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 010:T";
I048DataItems[ItemIDToIndex("010")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("010")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 010:F";
}
// 140 Time-of-Day
if (FourFSPECOctets[Bit_Ops.Bit6] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 140:T";
I048DataItems[ItemIDToIndex("140")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("140")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 140:F";
}
// 020 Target Report Descriptor
if (FourFSPECOctets[Bit_Ops.Bit5] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 020:T";
I048DataItems[ItemIDToIndex("020")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("020")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 020:F";
}
// 040 Measured Position in Slant Polar Coordinates
if (FourFSPECOctets[Bit_Ops.Bit4] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 040:T";
I048DataItems[ItemIDToIndex("040")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("040")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 040:F";
}
// 070 Mode-3/A Code in Octal Representation
if (FourFSPECOctets[Bit_Ops.Bit3] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 070:T";
I048DataItems[ItemIDToIndex("070")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("070")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 070:F";
}
// 090 Flight Level in Binary Representation
if (FourFSPECOctets[Bit_Ops.Bit2] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 090:T";
I048DataItems[ItemIDToIndex("090")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("090")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 090:F";
}
// 130 Radar Plot Characteristics
if (FourFSPECOctets[Bit_Ops.Bit1] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 130:T";
I048DataItems[ItemIDToIndex("130")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("130")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 130:F";
}
break;
case 2:
// 220 Aircraft Address
if (FourFSPECOctets[Bit_Ops.Bit15] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 220:T";
I048DataItems[ItemIDToIndex("220")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("220")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 220:F";
}
// 240 Aircraft Identification
if (FourFSPECOctets[Bit_Ops.Bit14] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 240:T";
I048DataItems[ItemIDToIndex("240")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("240")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 240:F";
}
// 250 Mode S MB Data
if (FourFSPECOctets[Bit_Ops.Bit13] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 250:T";
I048DataItems[ItemIDToIndex("250")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("250")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 250:F";
}
// 161 Track Number
if (FourFSPECOctets[Bit_Ops.Bit12] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 161:T";
I048DataItems[ItemIDToIndex("161")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("161")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 161:F";
}
// 042 Calculated Position in Cartesian Coordinates
if (FourFSPECOctets[Bit_Ops.Bit11] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 042:T";
I048DataItems[ItemIDToIndex("042")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("042")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 042:F";
}
// 200 Calculated Track Velocity in Polar Representation
if (FourFSPECOctets[Bit_Ops.Bit10] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 200:T";
I048DataItems[ItemIDToIndex("200")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("200")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 200:F";
}
// 170 Track Status
if (FourFSPECOctets[Bit_Ops.Bit9] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 170:T";
I048DataItems[ItemIDToIndex("170")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("170")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 170:F";
}
break;
case 3:
// 210 Track Quality
if (FourFSPECOctets[Bit_Ops.Bit23] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 210:T";
I048DataItems[ItemIDToIndex("210")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("210")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 210:F";
}
// 030 Warning/Error Conditions
if (FourFSPECOctets[Bit_Ops.Bit22] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 030:T";
I048DataItems[ItemIDToIndex("030")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("030")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 030:F";
}
// 080 Mode-3/A Code Confidence Indicator
if (FourFSPECOctets[Bit_Ops.Bit21] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 080:T";
I048DataItems[ItemIDToIndex("080")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("080")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 080:F";
}
// 100 Mode-C Code and Confidence Indicator
if (FourFSPECOctets[Bit_Ops.Bit20] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 100:T";
I048DataItems[ItemIDToIndex("100")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("100")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 100:F";
}
// 110 Height Measured by 3D Radar
if (FourFSPECOctets[Bit_Ops.Bit19] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 110:T";
I048DataItems[ItemIDToIndex("110")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("110")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 110:F";
}
// 120 Radial Doppler Speed
if (FourFSPECOctets[Bit_Ops.Bit18] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 120:T";
I048DataItems[ItemIDToIndex("120")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("120")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 120:F";
}
// 230 Communications / ACAS Capability and Flight Status
if (FourFSPECOctets[Bit_Ops.Bit17] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 230:T";
I048DataItems[ItemIDToIndex("230")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("230")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 230:F";
}
break;
case 4:
// 260 ACAS Resolution Advisory Report
if (FourFSPECOctets[Bit_Ops.Bit31] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 260:T";
I048DataItems[ItemIDToIndex("260")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("260")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 260:F";
}
// 55 Mode-1 Code in Octal Representation
if (FourFSPECOctets[Bit_Ops.Bit30] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 55:T";
I048DataItems[ItemIDToIndex("055")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("055")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 55:F";
}
// 50 Mode-2 Code in Octal Representation
if (FourFSPECOctets[Bit_Ops.Bit29] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 50:T";
I048DataItems[ItemIDToIndex("050")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("050")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 50:F";
}
// 65 Mode-1 Code Confidence Indicator
if (FourFSPECOctets[Bit_Ops.Bit28] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 65:T";
I048DataItems[ItemIDToIndex("065")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("065")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 65:F";
}
// 60 Mode-2 Code Confidence Indicator
if (FourFSPECOctets[Bit_Ops.Bit27] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 60:T";
I048DataItems[ItemIDToIndex("060")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("060")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " 60:F";
}
if (FourFSPECOctets[Bit_Ops.Bit26] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " SPI:T";
I048DataItems[ItemIDToIndex("SPI")].HasBeenPresent = true;
I048DataItems[ItemIDToIndex("SPI")].CurrentlyPresent = true;
}
else
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " SPI:F";
}
if (FourFSPECOctets[Bit_Ops.Bit25] == true)
{
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " Reserved Expansion";
}
break;
// Handle errors
default:
DataOut[DataOutIndex] = DataOut[DataOutIndex] + " UKN:T";
break;
}
}
DataOutIndex++;
CAT48DecodeAndStore.Do(LocalSingleRecordBuffer);
DataBufferIndexForThisExtraction = DataBufferIndexForThisExtraction + CurrentDataBufferOctalIndex + 1;
}
// Return decoded data
NumOfMessagesDecoded = DataOutIndex;
return(DataOut);
}
