Nanozond-1: Why 2 TM data bursts (high.low power)?

1

I often receive the UHF TM from Nanozond-1. 2 data bursts are sent at 4800 baud about each minute. The first data burst seems to have a better signal strength than the second burst about 15 seconds later, but the data sent seems to be identical (or almost identical) for many of the parameters, and different for others.

In the attached image the stronger data burst (TM1) results in data strings 1 and 2, whilst the second, weaker data burst is shown at the lower part of the image.

Why the difference?

DATA-NANOZOND-1
DATA-NANOZOND-11291×812 133 KB

2

You wonna know why there is a difference in signal strength?
I don’t know. Could be to save energy or to investigate if less transmission power is also enough to receive the signal.
My last reception is from May when the interval was at 30 seconds without any observable difference in signal strength.