coordinate precision

hi, i have dji phantom 4 pro drone. I was getting an error of about 2 cm in my previous photogrammetric work with this device. In the new photogrammetric study I made with the same device in the same measurement area, my error amount is between about 15 cm and 20 cm. I wonder which part of my device may have been damaged?

That seems to be right on par per the specs for the current Phantom 4 Pro. The GPS precision is within 0.1 meters (vertical) and 0.3 meters horizontal (best case scenario).

If you need something more accurate, maybe look into one of the enterprise drones (like the Phantom 4 RTK).

Thank you for your reply. In photogrammetry operations, using the longitudinal overlay ratios and transverse overlay ratios of the photographs and using the ground control points marked on the ground to be visible in the photographs, the coordinate precision can reach a few cm values (Ground sampling interval value is calculated with the flight height, focal length, sensor width and the number of pixels in the sensor width) . In the photogrammetry study I had done in the same area before, why did my sensitivity decrease now, while it was 2 cm/px sensitive? Could the device have a hardware problem?

I’m not sure why it decreased, but it seems it’s currently operating within the advertised specs.

Maybe I didn’t ask the question properly. I transfer the photos I took during my flight with my unmanned aerial vehicle to Agisoft Metashape software and transfer the ground control points whose coordinates I determined with a GNSS signal receiver to Agisoft Metashape software. I am processing Agisoft Metashape software in the order of operations on the site Aerial data processing (with GCPs) - Orthomosaic&DEM generation : Helpdesk Portal. I check the amount of error that occurs as a result of adjustment. The amount of error I am talking about is the errors in the check points and ground control points in the adjustment reports I received after the transaction with Agisoft Metashape software.
The amount of error you mentioned is the general sensitivity values of the coordinates obtained by the GNSS signal receiver during the photo shooting of the unmanned aerial vehicle without RTK feature. I understand what you’re saying.
The change in the amount of error I get with the balancing processes I mentioned above. My work is not just comparing two flight results. I do multiple experiments in the same measuring area and in different measuring area. I can’t get the adjustment results that I had previously with the Agisoft Metashape software. I am using licensed Agisoft Metashape software. Thank you for your reply. Maybe I explained myself better.