Windows real time software GPS receiver.

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I finished my first prototype for a windows real-time GPS Receiver for my
class project.
The latitude / longitude is within 10-20 meters however my altitude is
fluctuating greatly.

I am guessing that my pseudo ranges are too inaccurate.

The tracking loop is running at 8Mhz correlating every 1ms of data.

To improve the accuracy of the altitude should I do what of the following.
Perform correlation over 20ms instead of 1ms of data.

Decimate the tracking loop to 2 or 4Mhz and perform multiple early and late
calculations and use a curve fit to determine the correct CA offset.

I posted the binary here if any one wants to test it out.
http://attackofthesam.com/SDGPSR/wp-content/uploads/2009/04/SDGPSR.zip
It requires a dongle with the gn3s_firmware loaded.
Also included is a modified version of the fx2_programmer for windows.

Thank you,

Sam Price

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I finished my first prototype for a windows real-time GPS Receiver for my c=
lass project.<br>The latitude / longitude is within 10-20 meters however my=
 altitude is fluctuating greatly. <br><br>I am guessing that my pseudo rang=
es are too inaccurate.=A0 <br>
<br>The tracking loop is running at 8Mhz correlating every 1ms of data.<br>=
<br>To improve the accuracy of the altitude should I do what of the followi=
ng.<br>Perform correlation over 20ms instead of 1ms of data.<br><br>Decimat=
e the tracking loop to 2 or 4Mhz and perform multiple early and late calcul=
ations and use a curve fit to determine the correct CA offset.<br>
<br>I posted the binary here if any one wants to test it out.<br><a href=3D=
"http://attackofthesam.com/SDGPSR/wp-content/uploads/2009/04/SDGPSR.zip">ht=
tp://attackofthesam.com/SDGPSR/wp-content/uploads/2009/04/SDGPSR.zip</a><br=
>
It requires a dongle with the gn3s_firmware loaded.<br>Also included is a m=
odified version of the fx2_programmer for windows.<br><br>Thank you,<br><br=
>Sam Price<br>

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