Navagation processing between a tracker hardware device and a computer host based on a satellite positioning solution system
View Patent ↗Methods and systems consistent with the present invention provide a host based positioning system. The host based positioning system includes a tracker hardware interface that connects to a dedicated hardware space vehicle tracker to a host computer. The tracker hardware interface receives positioning information from the space vehicle tracker and communicates with the host computer using predefined messages. The host based positioning system includes a layered protocol approach to enable user applications on a host computer to access data from tracker hardware device.
1. A method of communication between a tracker hardware device and a computer host, comprising:
identifying a message to be formatted;
entering a start sequence into a message structure that defines the message;
entering a message identification and a message payload length in the message structure;
entering an end sequence into the message structure;
entering a length of the message derived from information in the message structure;
calculating a checksum for inclusion in the message structure based on information in the message structure; and
sending the message from the tracker hardware device via a tracker hardware link to the computer host that is locally located with the tracker hardware device, where the tracker hardware device is able to acquire and track satellites in a satellite positioning system.
2. The method of claim 1 , wherein entering the start sequence further includes:
placing 0xA0 and 0xA2 into the message structure for the start sequence.
3. The method of claim 1 , wherein entering the end sequence further includes:
placing 0xB0 and 0xB3 into the message structure for the end sequence.
4. The method of claim 1 , wherein calculating a checksum further includes:
solving an algorithm defined by:
index=first_byte
checkSum=0
while (index<msgLen)
checkSum=checkSum+message[index]
checkSum=checkSum AND (2^15−1)
Where message is the array of bytes to be sent and msgLen is the number of bytes in the message array to be transmitted.
5. The method of claim 1 , further comprises:
entering measurement data into the payload of the message structure having a message identification of 0x20; and
encoding in the payload data a channel number, bit number, millisecond number, carrier phase, code offset carrier Doppler rate, carrier Doppler frequency units, and time of measurement.
6. The method of claim 1 , further comprising:
waiting for receipt of an acknowledge message in response to the message sent by the tracker hardware link that may optionally be sent by the host compute.
7. The method of claim 1 , wherein identifying further includes:
determining the message to be formatted is an acknowledge message that is sent in response to receipt of another message at the tracker hardware device.
8. A method of communication between a tracker hardware device a computer host, comprising:
means for identifying a message to be formatted;
means for entering a start sequence into a message structure tat defines the message;
means for entering a message identification and a message payload length in the message structure;
means for entering an end sequence into the message structure;
means for entering a length of the message derived from information in the message structure;
means for calculating a checksum for inclusion in the message structure based on imformation in the message structure; and
means for sending the message from the tracker hardware device via a tracker hardware link to the computer host that is locally located with the tracker hardware device, where the tracker hardware device is able to acquire and track satellites in a satellite positioning system.
9. The system of claim 8 , wherein means for entering the start sequence further includes:
means for placing 0xA0 and 0xA2 into the message structure for the start sequence.
10. The system of claim 8 , wherein means for entering the end sequence further includes:
means for placing 0xB0 and 0xB3 into the message structure for the end sequence.
11. The system of claim 8 , wherein means for calculating a checksum further includes:
means for solving an algorithm defined by:
index=first_byte
checksum=0
while (index<msgLen)
checkSum=checkSum+message[index]
checkSum=checkSum AND (2^15−1)
Where message is the array of bytes to be sent and msgLen is the number of bytes in the message array to be transmitted.
12. The system of claim 8 , further comprises:
means for entering measurement data into the payload of the message structure having a message identification of 0x20; and
means for encoding in the payload data a channel number, bit number, millisecond number, carrier phase, code offset carrier Doppler rate, carrier Doppler frequency units, and time of measurement.
13. The method of claim 8 , further comprising:
means for expecting receipt of an acknowledge message in response to the message sent by the tracker hardware link that may optionally be sent by the host compute.
14. The method of claim 8 , wherein identifying further includes:
means for determining the message to be formatted is an acknowledge message that is sent in response to receipt of another message at the tracker hardware device.
15. A computer readable medium, with readable instructions stored on a computer readable medium storing a computer program for formatting a message in a tracker hardware device, comprising:
a first set of readable instructions for identifying the message to be formatted;
a second set of readable instructions for entering a start sequence into a message structure that defines the message;
a third set of readable instructions for entering a message identification and a message payload length in, the message structure;
a fourth set of readable instructions for entering and end sequence into the message structure;
a fifth set of readable instructions for entering a length of the message derived from information in the message structure;
a sixth set of readable instructions for calculating a checksum for inclusion in the message structure based on information in the message structure; and
a seventh set of readable instructions for sending the message from the tracker hardware device via a tracker hardware link to the computer h.o, st that is locally located with the tracker hardware device, where the tracker hardware device is able to acquire and track satellites in a satellite positioning system.
16. The computer readable medium of claim 15 , wherein entering the start sequence further includes:
an eighth set of readable instructions for placing 0xA0 and 0xA2 into the message structure for the start sequence.
17. The computer readable medium of claim 15 , wherein entering the end sequence further includes:
an eighth set of readable instructions for placing 0xB0 and 0xB3 into the message structure for the end sequence.
18. The computer readable medium of claim 15 , wherein calculating a checksum further includes:
an eight set of readable instructions for solving an algorithm defined by:
index=first_byte
checkSum=0
while (index<msgLen)
checkSum=checkSum+message[index]
checkSum=checkSum AND (2^15−1)
Where message is the array of bytes to be sent and msgLen is the number of bytes in the message array to be transmitted.
19. The computer readable medium of claim 15 , further comprises:
an eighth set of readable instructions for entering measurement data into the payload of the message structure having a message identification of 0x20; and
a ninth set of readable instructions for encoding in the payload data a channel number, bit number, millisecond number, carrier phase, code offset carrier Doppler rate, carrier Doppler frequency units, and time of measurement.