What is the datum of readings? 4326 or?

Reach RS2 / RS2+ Getting started
25

first off setting the survey projection doesnt produce a reprojection or the data, its just a label.

second 4326 is a generic EPSG container or label
it doesnt include a datum or epoch
it could be 4326 (WAAS 2015) or it could be 4326 (IGS08 2017) for example

CSRS Epoch 2017.50(NAD83))
4326 would not be the appropriate EPSG code to use for this

2 Likes
26

I understand. The RS2 costs $1900 USD. Prefer not to have to buy a 2nd one to use as a base and needing more time to set up and teardown on site.

27

if you are always working in a area with cellular service
and you have access to NTRP CRN
and your within the reasonable distance to your CRN correction station
then no it doesnt sound like a priority to go out and buy a second unit to work as a base station

28

Right. Thatā€™s my thinking.

29

So to test my understandingā€¦ Even though in Survey, it shows EPSG:4326, since am using an NTRIP that uses the CSRS reference, the points are in CSRS Epoch 2017.50(NAD83) reference too? And if so, CSRS Epoch 2017.50 is not available in dropdown menus in Pix4D. Given that, what coordinate or projection do I choose?

30

yes (there are numerous sources online that back this up)

I tuned in late to this thread, (looks like your in Rocklin, im in Napa FYI), i dont have a Drone/UAS but there is no reason why you cant produce all your products in the California CSRS (nad83). BUT you just have to watch out what other sources you are bringing into the mix.

31

If you are using this mostly for GCP and drone mapping I would suggest that you always PPK. You will get more reliable and certifiable results every time. Eventually get a second receiver to use as a local base and you donā€™t have to worry about this no matter where you are. Unless you are under a tree, lol. Which would happen anyways.

4 Likes
32

good point! allot of survey publications talk like post processing is dead and doesnā€™t make any business sense. but if you dont need real time feed back like with stake out operations then it makes sense to pursue a post proccess. i have recently seen false fixes with the RS+ (fix and hold) that looked good in real time but were actually 10cm off. i only caught this when i was practicing in a parking lot mapping the lines and then used PPK later on.

33

Absolutely. This is true for the high-end systems as well. False fixes are common. A 5-10 second condition of switching between fix and float easily gets us outside of our tolerances. This happening with a UAV travelling 18-20 mph is not an option. You would never know if unless you reviewed the data, which is why we always log 2nd generation control points for at least 2 minutes even with RTK. It is not easy to review the data unless you are running PPK or RTK with logs constantly running in the background and it is certainly not easy to do that with Topcon or Trimble. I donā€™t know about Leica, but I assume itā€™s the same.

The other piece is getting an RPLS to certify drone work. Thatā€™s not going to happen without PPK logs and if it does get ready for a lawsuit unless the RPLS set all the GCPā€™s and checkpoints. Way too expensive for us.

34

Hi @jmonaco,

At the moment, Reach RS2 handles the WGS84 coordinate system only. However, if it gets corrections from the base which position is specified in another coordinate system, the coordinates in the survey tool and in the position log will be provided in the baseā€™s system, even if itā€™s specified as WGS84 in ReachView.

2 Likes
37

This topic was automatically closed 100 days after the last reply. New replies are no longer allowed.