Frequency Steps in Acquisition

In the previous posts, a step size of 500 Hz was used. In the book, "Fundamentals of Global Positioning System Receivers A Software Approach", for 1 ms data blocks, we should use 1000 Hz, not 500 Hz. So let's compare results. For 1 block of data, a second peak really shows itself. Not very encouraging. It is important to note that the carrier was still 3125 and offset was 3107.



Let's try more blocks. We still get a 9-sigma hit, but it takes us 6 blocks, so we lost a little performance going to 1000 Hz steps.



To make it interesting let's attempt 250 Hz steps. It appears to have not really changed from the 1000 Hz example.



And for multiple blocks,



Once again, no real improvement over the 1000 Hz step. Note that just trying this on one SV and one set of data is really not statistically significant, but it is a good check to see which variables might have a hug impact on acquisition.