A7R: Geotagging images in the AIR

[BobvdMeij]

Dear all,

 

We are planning on purchasing a Sony A7R (or A7R ii) to be applied for aerial photogrammetry and survey operations. The camera will be mounted (using a Ronin MX gimbal) onboard of a powerful M600 Pro Unmanned Aerial Vehicle (UAV, or 'drone') that will be programmed to fly a grid-pattern mission. Through its flight the camera will be automatically triggered at regular intervals using either i) Time Lapse mode, ii) through an application we will be using for the actual flight planning or iii) using a more integrated solution as described under 3. below.

 

The thing is, in order to process the imagery afterwards some positional data of each image is desired to bring processing time within acceptable tolerances. Considering the A7R by itself embodies no GPS module we are searching for alternative solutions, we expect this will come down to one of the following:

 

1. An external GPS tracker/ logger (mounted on either the camera or the UAV itself) that continuously monitors its position (preferably 10Hz, or at least multiple positions per second). Afterwards we can then export the GPS log/ track and forward these to the EXIF image data based on time stamps of each.
2. A partially integrated (cable, BT, WIFI?) GPS tracker/ logger that can be connected to the A7R somehow and records its position either i) continuously or ii) every time the A7R is triggered (provided the A7R can send some sort of pulse to the device).
3. An even beter integrated GPS tracker/ logger that is actually capable of triggering the A7R autonomously. For example based on i) a pre-set time interval (e.g. every 2 seconds) or ii) distance covered since the previous photograph (based on the GPS track).

Now let me get this straight. I understand this may be a rather specific situation that very few of you may be familiar/ experienced with. The UAV/ photogrammetry component is of little importance though. I am particularly eager to find what setup others are using to geotag their images, assuming geotagging is something only aerial photographers are interested in! Any information on how you add the geotags during post-processing (using what software?) is also much appreciated!

 

Some additional considerations that might be relevant taking note of:

1. Much heard solutions relying on smartphone based devices/ apps are off little use to us, considering the UAV is 120m up in the air and up to 500 meters horizontally away from us. We are looking for the (approximated) location of the camera/ UAV.

2. The device does not necessarily have to be mounted on the camera itself, it may just as well be mounted on the gimbal or on-top of the UAV itself. In case the device IS capable of communicating with the A7R, some connection (cable, WIFI, BT) between the two is wished for obviously.

3. Partially following from the above; we are not looking for the exact absolute position of the camera itself. The position of the UAV itself will do just fine. We only need to know the approximate location of each image so we can tell how their positions relate relatively.

4. In case the device is not triggered to record a position by the camera (but rather logs its position continously), its refresh/ update frequency (Hz) is import. I have come across various devices that log a position every minute or even seconds. We, however, are ideally looking for a device that records multiple (i.e. 10+) positions per second.

 

Thanks in advance!

[BobvdMeij]

No one?

[Paul7of8]

I have an A7RII and I have looked, not extensively, for a way to geotag images in real time (like I had been able to do with my Nikon cameras a Solmeta GPS unit).  I have never found anything.

 

I don't geotag all photos, but when I do... I use my Garmin GPSMAP 64st.  I make sure that the Garmin and the Sony have pretty much the same date/time.  To make things really easy, I usually snap a photo of my Garmin showing the current date/time so that I can later make adjustments if needed.

 

I have used Photo Mechanic (by Camera Bits) to add the GPS coordinates from the Garmin to my Sony ARW files.  I have also used Exiftool to do the same thing.

 

I suspect you could easily get a GPS data logger and use an application like Photo Mechanic or Exiftool to do the same thing in your situation.