What's gone wrong here?

[Mal22]

Hello,

Hoping for some advice following an issue I've had with corrupt files after an imaging session last night.

Using ASIAir I had set up the scope to Autorun through the night tracking the Elephant Trunk Nebula with 180 sec subs. At some point during the night, a large chunk of the FITS files became corrupted and I can't open them. I've tried opening them on Deep Sky Stacker, PixInsight and ASIStudio and get the same error message, which is:

"Error Message: 1st key not SIMPLE or XTENSION".

Out of the 95 subs it was due to take. 26 work fine, and the rest get that error message. The first two subs from the night definitely worked as I watched them live, but by the morning they'd become corrupted and get that error message. The ones in between around 10:45 and 1am are all fine. And then every sub from 1am onwards gets the error message. I have a USB stick inserted directly into the ASIAir to store the subs while they are being gathered.

The corrupted files are the same file size as the non-corrupted file, so they obviously worked at some point.

My set up has worked fine for me for many previous nights of imaging without this issue occurring.

Any idea what's happened here? And is it possible to salvage the corrupt files? It would be a shame to lose about 4 hours of imaging on a nice clear night!

I do have my dew heater strip, mount and camera powered via the inputs on the ASIAir and from searching online it seems possible that the issue could have been caused by power (but I've had it set up this way for a while with no issues before). The whole set up is plugged into the main supply in the house though, not powered via a power pack.

I've attached one of the files that works "0008", and one of the files that is corrupted "0038" - do these give any clues?

Very grateful for any advice! It's another clear night tonight so I'm hoping to prevent it from happening again.

Light_HIP 106890_180.0s_Bin1_20230526-232847_-14.1C_0008.fitLight_HIP 106890_180.0s_Bin1_20230527-012447_-14.1C_0038.fit

[david_taurus83]

Sorry to hear you've lost a few hours of work! Its kinda like when you leave everything running after being happy with the first few subs to find the next day the rest are ruined by un-forecast high clouds!

I've also been unable to open that corrupted file. I tried to change it to an .xisf file and a tiff file but Pixinsight says no. I would suggest saving files direct to the ASIAir unit while imaging and transfer afterwards.

[Mal22]

15 hours ago, david_taurus83 said:

Sorry to hear you've lost a few hours of work! Its kinda like when you leave everything running after being happy with the first few subs to find the next day the rest are ruined by un-forecast high clouds!

I've also been unable to open that corrupted file. I tried to change it to an .xisf file and a tiff file but Pixinsight says no. I would suggest saving files direct to the ASIAir unit while imaging and transfer afterwards.

Thanks for trying @david_taurus83! 
 

I’m pretty certain the USB stick was to blame… I’ve since found out that whatever happened that night also corrupted some subs I had on the stick from an imaging session a week earlier but hadn’t transferred, which had been fine until then. 
 

Annoying but life goes on! I’m now saving direct to the ASIAIR as you suggest. I’m also plugging my dew heater into a separate power source from now on… just in case. I managed a nights imaging the night before last with no corrupt files, so hopefully problem solved…