What is 1100tom.to4 ??? Odd file found on EOS R5 Mark II card

[pedz]

I rarely connect my camera to Canon's Camera Connect but I did this morning to move an image to my iPhone.  I was using my R5 Mark II and that was the camera I connected to.  It told that there is new firmware for my R7 and do I want to download it?  I canceled the download.  Move one image to my phone and then put the camera back into Airplane mode.

But now that I look at the CF card, I see a weird file named 1100tom.to4 that is timestamped when I was mucking with Camera Connect.  Does anyone know what it is?  Has anyone seen it before?  macOS's "file" as well as Linux's "file" utility simply says "data".  It is 320960 bytes with all but about 8 to 12 characters null.  The "to4" file extension seems to be some ancient compression.

I plan to just delete it but it is kinda unsettling.

[FloridaDrafter]

Those are data files. Where I've seen them is when downloading high precision GPS, GIS, and GNSS observations with Trimble surveying equipment.

Newton

[FloridaDrafter]

After thinking about it, I will add that they were, in my case, compressed raw data from satellite observations that needed to be adjusted with the Trimble s/w that we used on our data collectors. After adjusting, I would bring the data points into either ESRI ARC GIS or Autodesk Land Development Desktop.

I guess, in your case, it's GPS coordinates?

Newton

[pedz]

• I don’t know what it is.  I’ve never seen it before nor heard of the .to4 extension.  My guess is if I would have yet the download of the R7 firmware it would have cleaned things up.

I guess an app called “Top 4” is used to uncompress it but my searches for that app get confused and think I’m asking what are the top 4 apps.  🥺

[FloridaDrafter]

It's my understanding that they are currently intended to be read by whatever software you are using to collect the data, in my case it was the Trimble data collector. Another instance was with our drones. There is very little you can do with the Raw compressed satellite data on its own. It has to be adjusted. Sure, you can open the file, but unless you give the data a reference, it's just gibberish or may make your drone fly into a tree, LOL!

Nowadays, in a non surveying and mapping environment, it is used in commercial drones, like the upper end DJI drones (just one example) that are used for GIS mapping.

Now, originally they were simple compressed data files, think ZIP, and would (and still can) contain documents, programs, and various other info. That's where the TOP 4 software was used. But not so much any more.

Not sure why it downloaded to your card unless something thought it was a drone camera.

Newton