[OpenSource_GPS] Combined Doppler effect on Carrier and Code DCO

Gustavo gustavo at spacetec.zarm.uni-bremen.de
Fri Oct 13 11:11:49 PDT 2006

Hi there,

Could anyone help me on this?

I have the following data:

Carrier DCO freq resolution: carrier_fr = 42.57475e-3 Hz
Code DCO freq resolution: code_fr = 85.14949e-3 Hz
L1 frequency:  L1_HZ = 1575.42e6 Hz
Speed of light: C = 300e6 m/s
Carrier DCO reference frequency in increments: carrier_ref_incr
Code DCO reference frequency in increments: code_ref_incr

Clock drift in s/s: cd
Relative speed: rel_vel

I convert clock drift into speed:
cv = cd*C

I convert clock speed into doppler freq Hz:
clock_dopp = -cv*L1_Hz/C

I convert relative speed into doppler freq Hz:
speed_dopp = -rel_vel*L1_Hz/C

How should I compute carrier and code DCO increments using
clock_dopp, speed_dopp, carrier_fr and code_fr?

I thought:
code_DCO_corr = (clock_dopp + speed_dopp)/code_fr
carrier_DCO_corr = (clock_dopp + speed_dopp)/carrier_fr

Then I can compute the doppler corected carrier and code DCO freqs:
carrier_DCO = carrier_ref_incr + carrier_DCO_corr
code_DCO = code_ref_incr + code_DCO_corr

Is that correct?


Msc. Eng. Gustavo Baldo Carvalho
ZARM - Uni-Bremen - Room 1210
Am Fallturm, 28359 Bremen

opensource_gps-request at lists.psas.pdx.edu wrote:
> Send opensource_gps mailing list submissions to
> 	opensource_gps at lists.psas.pdx.edu
> To subscribe or unsubscribe via the World Wide Web, visit
> 	http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
> or, via email, send a message with subject or body 'help' to
> 	opensource_gps-request at lists.psas.pdx.edu
> You can reach the person managing the list at
> 	opensource_gps-owner at lists.psas.pdx.edu
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of opensource_gps digest..."
> Today's Topics:
>    1. Release of OSGPS 2.00 (Clifford Kelley)
> ----------------------------------------------------------------------
> Message: 1
> Date: Wed, 27 Sep 2006 20:40:05 -0700 (GMT-07:00)
> From: Clifford Kelley <cwkelley at earthlink.net>
> Subject: [OpenSource_GPS] Release of OSGPS 2.00
> To: opensource_gps at lists.psas.pdx.edu
> Message-ID:
> 	<1291291.1159414805755.JavaMail.root at elwamui-karabash.atl.sa.earthlink.net>
> Content-Type: text/plain; charset=us-ascii
> Andrew Greenberg has informed me that I neglected to post to the list the fact that OSGPS 2.00 has been released on sourceforge.  
> Version 2.00 supports both DOS and Linux.  Rick Niles has ported version 1.18 to operate as a device driver under Linux and cleaned up alot of the code.  In addition the pull-in and tracking loops have been modifed to put them into the standard format seen in GPS textbooks.  More documentation needs to be included.
> The response at ION GNSS 2006 has been great and we are looking forward to more collaboration and improvements in the next year.
> Best regards,
> Cliff
> ------------------------------
> _______________________________________________
> opensource_gps mailing list
> opensource_gps at lists.psas.pdx.edu
> http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
> End of opensource_gps Digest, Vol 35, Issue 7
> *********************************************

More information about the opensource_gps mailing list