Comparison Between 8-bit and 1-bit Data Results

The collection of raw IQ data makes for very large files - approximately 17.3 GB per hour. To see the effect of compressing that data on the results, data was first processed using the original 8-bit IQ values, then processed again with data in 1-bit form (data taking two values: +1 and -1). The 1-bit conversion was done by replacing negative values in the 8-bit range (-128 to -1) with -1, and replacing positive 8-bit values (0 to +127) with +1. The results are shown below; reading left to right - LAB survey result, 8-bit result, 1-bit result...

As can be seen some noise is added to the result when using 1-bit data, but the essential result is preserved. Taking into account that the 1-bit data can be packed into the bits of an unsigned 8-bit byte, and thereby reducing the size of the saved data files by a factor of 8, consideration should be given as to whether the small increase in noise is a good trade-off.

Note: separate 'dark frame' files needed to be created for the 8-bit and 1-bit cases.