Best Practices to Connect an Emlid Reach RS2 Base to an Autel Evo II Pro Enterprise RTK Drone

[jmason702]

4 GCPs and 2 CPs, I would recomend

 

[jmason702]

I feel I am getting to the point I don't need GCPs, just 2 or 3 CPs to check accuracy

here is an accurate report of a 50 Acer map, just one example

I f trimmed the edges of the map it would be even better, you see were it turns around is were you get a lil out of place

 

[Malli35998]

Z= .96 inch

We have run many tests against checkpoints and ave. 2 to 4 cm.

Great results! Thanks so much for sharing.

 

[jmason702]

think of the RS2 when connected to NTRIP, all its doing is having a very strong connection to the NTRIP station and passing along the corrections to the ROVER, (DRONE)
SO not a lot of the particulars matter when setting up your base.

 

[Malli35998]

I plan to reshoot the survey tomorrow (Tuesday) using your recommendations. If time permits, I may shoot using both Average FIX and Manual for Base Mode.

 

[Malli35998]

I use SimActive's Correlator3D (C3D) for post processing (vs Pix4D, others). I need to convert the RTK-corrected drone data from ellipsoid height to ortho height. C3D can export a DEM with a Geoid (e.g., GEOID12B) applied. The geoid file needs to be in .gtx format. Using the NOAA National Geodetic Survey VDatum Site (NOAA/NOS's VDatum: Download VDatum) I was able to download the GEOID12B data and apply to the DEM.

 

[Malli35998]

I use a 2-meter pole and add the 134mm to that for the height of the RS2

Per the attachments, for the RS2, it looks like the 134mm (0.134m) is automatically added to the pole height (2m) or 2.134m .

 

[Malli35998]

I plan to reshoot the survey tomorrow (Tuesday) using your recommendations. If time permits, I may shoot using both Average FIX and Manual for Base Mode.

I did reshoot the test survey this morning. Skies were overcast and cloudy. Some rain in the area. I had trouble initially getting the RS2 to connect to my mobile hot spot (my iPad). Lots of reading and troubleshooting but I finally got the RS2 and my Autel Smart Controller to connect to my iPad hot spot. Good NTRIP connection on both devices. I used Average FIX for the Base Mode. Unfortunately, bad weather did not permit me to shoot in Manual. I processed the one dataset acquired using the Average FIX for the Base Mode. Everything looked good. After the Aerial Triangulation (AT) step was completed I reviewed the Quality Report. The results were relatively poor. I don't know why. I attached the Quality Report (5-03-22) for your reference. This was not the case using Manual as a Base Mode for the previous drone survey (4-28-22). Average projection error on 4-28-22 was 0.69 pixels and average number of tie points per image was 95.9. Average projection error on 5-3-22 was 1.62 pixels and average number of tie points per image was 93.3.. Any thoughts/suggestions as to why the average projection error is so much higher?

 

[yarrr]

I haven't used C3D since last summer, but first thing that comes to mind is perhaps your number of tie points is low? Particularly if you had bad weather or blurry images?

 

[Malli35998]

I haven't used C3D since last summer, but first thing that comes to mind is perhaps your number of tie points is low? Particularly if you had bad weather or blurry images?

Skies were overcast and cloudy. Some rain in the area. The images look ok. Generally, in pretty good focus. I am reprocessing using Extraction Type Exhaustive vs Standard.

 

[jmason702]

Interesting, I think the cloudy overcast may have played a role? I have never had an issue with NTRIP and the average fix,I may play with this also this weekend to see for myself

 

[jmason702]

In base mode on the RS2 how long do you have it collect data before it sets on the coords?

 

[Malli35998]

Interesting, I think the cloudy overcast may have played a role? I have never had an issue with NTRIP and the average fix,I may play with this also this weekend to see for myself

How long do you let Average FIX go? 5 minutes? Any other settings?

 

[jmason702]

I do 10 min, while I'm setting up the drone and everything else
Are you collecting data at 1 hz or 5hz

 

[Malli35998]

How long do you let Average FIX go? 5 minutes? Any other settings?

How long do you let Average FIX go? 5 minutes? Any other settings?

5 minutes

 

[jmason702]

5 minutes

5 min should be fine also

 

[Malli35998]

I do 10 min, while I'm setting up the drone and everything else
Are you collecting data at 1 hz or 5hz

OK. 5hz

 

[jmason702]

I set mine to 1 but you still should be ok, in base mode do you have the base set to static? or moving. I have mine set to static I belive its called

 

[Malli35998]

I set mine to 1 but you still should be ok, in base mode do you have the base set to static? or moving. I have mine set to static I belive its called

I am not sure. I will have to check.

 

[jmason702]

how do you like sim active? ( I never have used it) how do you feel it compares to PIX or DD? and is it cloud-based or CPU-based?