RBE970 and Satellites Rebooting Randomly?

Those are the hourly checks about internet connection up or down. Nothing to be worry about. In my config, those checks are once every 12 hours, in your side every hour.

But those logs don't give required info about the crashes/reboots.

I have a very similar config a bit simple than your one :  971R + 1 satellite  with wireless backhaul with latest fw 9.12.5.3 and I also have reccurent crashes some times once every 2-3, simetimes 1-2 per day...

You have to activate debug logs and extract/downloaf them after the crash and share it with NG Support (you should create a ticket with NG Support) 

To activate the debug logs in your config

• go to : http://192.168.1.2/debug.htm
• Under " Debug Log Capture", check the 2 boxes
• Start Debug Log Capture when boot up
• Enable LAN/WAN Packet Capture
• Click on  "Start Capture"

After the crash/reboot :

• go to again to the same page and click on "Save Debug File".
• That will generate debug_log.zip file that you should download into your PC.
• Extract this zip file on your PC, and check for the file oopsdump.
• If the file "oopsdump" exist , please open it with Notepad and search for "Kernel   panic" with a timestamp"
• If you have 1  or more lines like that, you also have similar crash issues. 

You must share all zip file with NG Support for furthe investigation of the root cause...