Hello Lyuboslava,

As you said, the first thing that came to mind was running a CV program to read the needed data. If the data does not change in the duration of the footage, then, in my humble opinion, it would be easiest to take a single frame from each clip and run an optical character recognition program to get the temperature.

The moon phase might pose a bit more of a challenge if the meta data truly is hidden. A different CNN program that is trained on the moon phases should suffice. But as you well know, not the simplest solution.

It's certainly possible that your camera(s) just aren't embedded structured metadata for this information.  But I wouldn't give up too quickly on looking for it, because extracting it from actual video frames is more challenging, less efficient, and less reliable.

EXIF / IPTC metadata is effectively limited to a finite set of pre-defined attributes, mostly centred around camera settings & author information, respectively.  You can check the latest specification to see precisely what is formally defined.  Ambient temperature actually is in there (and has been for a while) but there's nothing for astronomical data (although, can you not infer the moon phase based on the location & time data?).

It is alas a long-running issue that camera makers often misunderstand the specification and store data incorrectly (or not at all).

Camera makers can embed proprietary data in MakerNote fields, but the format is unspecified and standard tools (like exiftool) likely won't understand them for all but the most popular cameras (think Nikon, Canon, Sony, etc).  And possibly only for older models.

Many common image & video containers (e.g. JPEG and MP4) do support embeded XMP, an extensible format which allows model- and make-specific metadata.  It's possible that's in use in your case.  exiftool does not show embedded XMP data by default - at least not reliably.  In a nutshell, I suggest running exiftool as:

exiftool -D -g -G -ee -scanForXMP -u -U <PATH>

That's more likely to show you embedded XMP data, as well as all EXIF / IPTC tags (even those unrecognised by exiftool - you can at least get their raw bytes and work from there).  You can also add the `-v3` argument if you want to dig even harder, or see the raw data in more detail.

Another way some cameras store proprietary metadata is in proprietary tracks (e.g. GPMF for GoPros).  You can see if your files contain any such tracks via:

ffmpeg -i <PATH>

Usually these are used for metadata which can change during a recording, as EXIF / IPTC / XMP have no real support for that.  But some camera makers use them even for static metadata out of e.g. laziness or hubris.

Extracting such tracks is easy enough with tools like ffmpeg, but interpreting them can be challenging if their format is not documented like GoPro's GPMF.

Can you provide a sample file for us to examine?

Hi Thomas !

Thanks for sharing! I know one of the Danish authors of the KInefox paper. It is very cool stuff and we hope to one day use something like this on muskoxen in Greenland.

Some of the limitations are obviously the relatively limited number of daily fixes. Also, we would probably need satellite based communication, but since the authors from Max Planck are also heavilly involved in the https://www.icarus.mpg.de/en project, I hope this kinetic energy harvesting gets incorporated in the satellite based ICARUS trackers one day.

The article you linked to refered to this paper with a dizzying list of recent energy harvesting studies:

Recent progress in energy harvesting systems for wearable technology

This paper provides a comprehensive review of the recent progress made in energy harvesting systems for wearable technology. An energy-harvesting syst…

It also seems well worth a look.

This is very cool @ThomasGray_Argos !! I tried years ago to build a benchtop version of something similar, using a 'kinetic' torch assembly, but never got much further than some very crude designs. I even approached Seiko about their watch mechanisms, but in the they weren't interested...

It's really great to see this technology get applied and I hadn't heard of the Kinetron microgenerator the researchers used. They did a fantastic job designing their system and bonus points for releasing it all to open-source! The only thing I couldn't see were costs or a bill of materials (and I could've easily missed it), as I was keen to see how much the Kinetron microgenerator was. The hybrid capacitor they used was great value at AU$7.19. 

My next project is to try harvesting radio waves using something like this: 

AEM30940 Radio Frequency Energy Harvesting Power Management IC

RF energy harvesting IC AEM30940 is a new generation solution for harvesting radio frequency energy at ultra-low-power. We make your batteries last forever.

E-peas

Urban environments might have enough ambient sources of radio waves that no additional transmission stations are needed, but for remote locations, purpose-built transmitters could work for critters that have defined, and relatively small home ranges. 

Anyway Thomas, thanks heaps for sharing and very interesting and encouraging. 

Rob

ooh very cool Salman! Amazing how much tracking devices have come down in price over the years and LoRa/LoRawan is just such a perfect fit for GPS data. Thanks heaps for sharing.

All the best,

Rob

There is the Conservation Tech Directory! There's an 'open-source' tag you can search by too.