CodeBuffer Class Reference
[Code generator]

#include <CodeBuffer.hpp>

Collaboration diagram for CodeBuffer:

[legend]List of all members.

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Detailed Description

P(Y)-code Buffer class.

Applied Research Laboratories, The University of Texas at Austin August 2003

CodeBuffer is a helper class designed to store P-code information. Six seconds of code for a particular satellite is stored in each object. The satellite is identified by PRNID and the beginning time is specified in a CommonTime object. The code is stored in an array of unsigned long (assumed 32-bit) integers. The time order started with the MSB of first word of the buffer ([0]) and runs through the LSB of the last word of the buffer.

The size of the buffer is probably the most notable feature of this class. 1.5s (one Z-count) of P(Y)-code is 15,345,000 bits. Therefore, 6 seconds is equal to 4 Z-counts or 4 * 15,345,000 bits = 61,380,000 bits. These bits are stored in 1,918,125 unsigned long integers. The fact that 61,380,000 is evenly divisble by 32 is not a coincidence, but part of the design. The constant NUM_6SEC_WORDS is used to hold the value 1,918,125 and located in PCodeConst.h.

Definition at line 81 of file CodeBuffer.hpp.

Public Member Functions
	CodeBuffer (const int SVPRNID)
	Instantiate and initialize a code buffer for a particular satellite.
	~CodeBuffer ()
CodeBuffer &	operator= (const CodeBuffer &c)
void	updateBufferStatus (const gpstk::CommonTime &dt, const codeType PYFlag)
	Update the time associated with the buffer and the designation of the data contained in the buffer as P-code or Y-code.
void	updateBufferStatus (const codeType PYFlag)
	Update the time associated with the buffer and the designation of the data contained in the buffer as P-code or Y-code.
const gpstk::CommonTime &	getCurrentTime ()
	Accessor returning the current time.
codeType	getPYFlag ()
	Accessor returning the type of code in the buffer (P or Y).
int	getPRNID ()
	Accessor returing the PRN ID of the buffer.
unsigned long &	operator[] (int i)
	Set or return the designated word of the code buffer.
const unsigned long &	operator[] (const int i) const
unsigned long	getBit (const long i) const
	Given a bit number between 0 and (NUM_6SEC_WORDS * MAX_BIT) - 1, return the value of the bit as a right justified unsigned long word (0x00000000 or 0x00000001)..
CodeBuffer &	operator^= (const CodeBuffer &cb)
	Perform an exclusive-or operation on the bits contained in this instance of CodeBuffer and the instance referenced by cb.
Protected Member Functions
	CodeBuffer (const CodeBuffer &c)
Protected Attributes
unsigned long *	buffer
int	PRNID
gpstk::CommonTime	currentTime
codeType	POrYCode

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Constructor & Destructor Documentation

CodeBuffer (  const int  SVPRNID  )

Instantiate and initialize a code buffer for a particular satellite. Definition at line 44 of file CodeBuffer.cpp. References CodeBuffer::buffer, CodeBuffer::currentTime, CodeBuffer::POrYCode, and CodeBuffer::PRNID.

CodeBuffer (  const CodeBuffer &  c  )  [protected]

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Member Function Documentation

const gpstk::CommonTime& getCurrentTime (   )  [inline]

Accessor returning the current time. Definition at line 111 of file CodeBuffer.hpp.

int getPRNID (   )  [inline]

Accessor returing the PRN ID of the buffer. Definition at line 117 of file CodeBuffer.hpp.

codeType getPYFlag (   )  [inline]

Accessor returning the type of code in the buffer (P or Y). Definition at line 114 of file CodeBuffer.hpp. References gpstk::codeType.

CodeBuffer & operator= (  const CodeBuffer &  c  )

Definition at line 53 of file CodeBuffer.cpp. References CodeBuffer::buffer, CodeBuffer::currentTime, CodeBuffer::POrYCode, and CodeBuffer::PRNID.

void updateBufferStatus (  const codeType  PYFlag  )  [inline]

Update the time associated with the buffer and the designation of the data contained in the buffer as P-code or Y-code. In this case, the time is not being changed, but the code flag may be changed. Definition at line 108 of file CodeBuffer.hpp.

void updateBufferStatus (  const gpstk::CommonTime &  dt, const codeType  PYFlag )

Update the time associated with the buffer and the designation of the data contained in the buffer as P-code or Y-code. Definition at line 65 of file CodeBuffer.cpp. References CodeBuffer::currentTime, and CodeBuffer::POrYCode. Referenced by SVPCodeGen::getCurrentSixSeconds().

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Member Data Documentation

unsigned long* buffer [protected]

Definition at line 136 of file CodeBuffer.hpp. Referenced by CodeBuffer::CodeBuffer(), CodeBuffer::getBit(), CodeBuffer::operator=(), CodeBuffer::operator[](), and CodeBuffer::operator^=().

gpstk::CommonTime currentTime [protected]

Definition at line 138 of file CodeBuffer.hpp. Referenced by CodeBuffer::CodeBuffer(), CodeBuffer::operator=(), and CodeBuffer::updateBufferStatus().

codeType POrYCode [protected]

Definition at line 139 of file CodeBuffer.hpp. Referenced by CodeBuffer::CodeBuffer(), CodeBuffer::operator=(), and CodeBuffer::updateBufferStatus().

int PRNID [protected]

Definition at line 137 of file CodeBuffer.hpp. Referenced by CodeBuffer::CodeBuffer(), and CodeBuffer::operator=().

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The documentation for this class was generated from the following files:

• CodeBuffer.hpp
• CodeBuffer.cpp

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