If the focus of your survey is primarily the fidelity of the DSM (topography), then you want to use the nadir mission type.
If the the aesthetic of the 3D model is the primary goal, then the oblique mission is correct.
M4T RTK accurate or not ..
- Thread starter Mflyer
- Start date
If the the aesthetic of the 3D model is the primary goal, then the oblique mission is correct.
Thanks. In this case the focus of the survey was to test the accuracy of M4T with RTK (I've used Base+Rover approach - DJI RTK3 + M4T). Because I've seen here different results from what I've obtained I was wondering where I was wrong.
At this point in the state of the processing technology, nadir image sets provide more accurate z values.
@jaja6009 error results for z on the M4T / Oblique without GCPs was over 1 foot. So worse than your 20cm. With GCPs, it dropped to .7 feet (21.34cm)
Attachments
I refer to this test
Test 1 Nadir Images with Altitude Optimization, 5 Check Points, No GCPs.
X: 3.14 cm, Y: 1.95 cm, Z: 8.14 cm Total: 8.93 cm
Test 2 Smart Oblique, 5 Check Points, No GCPs and we have a winner!
X: 1.98 cm, Y: 1.98 cm Z: 3.26 cm Total: 4.29 cm
Test 1 Nadir Images with Altitude Optimization, 5 Check Points, No GCPs.
X: 3.14 cm, Y: 1.95 cm, Z: 8.14 cm Total: 8.93 cm
Test 2 Smart Oblique, 5 Check Points, No GCPs and we have a winner!
X: 1.98 cm, Y: 1.98 cm Z: 3.26 cm Total: 4.29 cm
I would consider that result, i.e that the smart oblique was better, as an anomaly comparing it to all of the other tests. Not the standard. Your own text confirmed that the nadir set produced better results. You need not take my word for it. Do a dozen more tests on your own and confirm it for yourself.
Thank you. This is because oblique images (from Smart oblique) "confuse" more the photogrammetric process than just a few obliques in the "elevation optimizatione" mode ? Would it be better using the M4E ?
I'm not sure as to the "why". It may be that there are more variables for the processor to deal with using obliques compared to nadir images. Less similarity between potential tie points for example. But I don't really know.
Over all, the M4E would be a better platform if topography is the goal. If all else is the same, position accuracy, and image time stamping, etc., the M4E has a global shutter. But no thermal, obviously.
Over all, the M4E would be a better platform if topography is the goal. If all else is the same, position accuracy, and image time stamping, etc., the M4E has a global shutter. But no thermal, obviously.
