How to collect GCP's with Reachview3 and Emlid RS2

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In this week's Friday 5 I show you how to collect GCP's (ground control points) using the Reach RS2 Base and Rover and the Emlid Reachview3 app. Next week's Friday 5 will cover exporting these out from the tablet or phone and processing them in Emlid Studio.
If you only have 1 Emlid RS2 (or RS+) GNSS Receiver, then you can use a CORS Station to process the one RS2 Rover. If you have an RS2, the CORS station can be up to 60 miles away and get good results. If you have the RS or RS+ then you need to keep in mind 2 things. Your log time needs to be at least 30 minutes and the CORS station should be within 12 miles. You can still do PPK processing with a longer baseline but your accuracy will diminish when the CORS station extends beyond 12 miles.
If this video is helpful please give it a thumbs up! Let me know in the comments below if there are specific topics you would like to see videos on.
Thanks for watching and have a super duper day!

[@stevenjohnson8993]

All your videos are very informative. Thanks for taking the time to do these. Would really like to see a video on selection of the coordinate systems and ellipsoidal vs using a Geoid. How do know what the CORS station is using and what others on your jobsite typically use so everything works together. That part confuses me. Thanks

[@Louisianahelicam]

Good video, Tim

[@dojifly]

Thank you.

[@ekalb7789]

Thanks!

[@xiaobingzhou7394]

I saw you put NTRIP for Correction input/output. How did you set up NTRIP? Thank you for the help.

[@edgardoprado6688]

Buenos días. Excelente video, ojalá continúen produciendo más contenido sobre este apasionante tema. Te comento que soy nuevo en el ámbito del gnss, por lo que pido tu ayuda con lo siguiente: Es correcto el siguiente flujo de trabajo Stop & Go? 1. Iniciar la base con coordenadas conocidas (formato ubx o rinex, y en modo estático). 2. Iniciar el rover y configurarlo igual que la base, con la diferencia que este rover seria cinemático (ambos equipos a 1 herzt). 3. Para iniciar el trabajo de campo: El equipo estático o base debe estar encendido y capturando data gnss en formato ubx o rinex. Paralelamente, el rover debe estar capturando data gnss, y en este rover móvil debo capturar también los puntos de detalles que el Reachwiev lo guarda en csv. ¿Hasta aquí, es correcto el procedimiento o flujo de trabajo? Tengo las siguientes consultas: 1. En vez de estacionar la base, puedo usar la data gnss de una estación de rastreo permanente (postproceso). 2. Los equipos (Emlid) necesitan estar enlazados vía Lora? Gracias mil por vuestra ayuda, y en espera de sus comentarios. Edgardo

[@rameshmanisk8229]

Thank you. Could you suggest me, can we use Sparkfun facet data as gcp’s

[@DroneMappingTools]

Hi Ramesh, I am assuming you are asking if you can use the Sparkfun GPS/RTK Receiver? You can use any GNSS receiver to collect (survey) ground control points. But the accuracy could vary greatly depending on what unit you are using. The accuracy of the Reach RS2 is very good. I have no idea on the accuracy of the Sparkfun receiver. It would also depend on the quality of antenna that you paired with it. I highly recommend using a dual frequency receiver which will allow for a longer base line (distance between your rover and base unit). If you are using a Sparkfun GPS receiver, which generates a UBX file. Paid software such as EZsurv and TopoSetter would process it. and I am sure that RTKlib could process it just fine but I don't know for sure.

[@rameshmanisk8229]

@@DroneMappingTools Thank you. I understand. It can be used along with software like ezsurv and SW maps. Thank you once again.

[@kgfworld1169]

Why set it in 1hz ? In the default is 5hz

[@luckypennybenny]

Does the GCP file i create have to be in WGS84 UTM zones in meters to work with DJI? I'm guessing yes but, i just cant seem to find the simple answer.

[@DroneMappingTools]

Hi Benny, you can survey the GCP's in any CRS. It can be WGS84 Lat/Lon, WGS84 UTM, NAD83 State Plane Coordinates. etc. Because when you do your photogrammetry processing, you will specify which CRS the GCP points are in. Ideally you have a Base/Rover setup for your mapping mission. If so, you would fly your M3E using RTK with your onsite base being the reference. If you are using Emlid units, you can do RTK a variety of ways (see my video on that). If you are using Stonex then you can use www.rtk2go.com for RTK or local NTRIP just like the Emlid units. Same goes for Carlson BRX7 units. I hope this helps. I always survey the GCP's in the CRS (coordinate reference system) that the job will be delivered in. So if I do a job for the engineer and they want the files to be in NAD83(2011) Mississippi West us survey feet, then that is what I shoot my GCP's in. Then when I use DJI Terra, Pix4D, Agisoft, or any other photogrammetry I will specify that the final CRS is the same (MS West). Hope this helps. Holler if you have questions.

[@ryanwallner]

Does 2 minutes vs 10 seconds make a large difference in accuracy of the surveyed point ?

[@DroneMappingTools]

In my opinion yes it does I only did 10 seconds because this was a demo video. When capturing Ground Control points I use a bipod and let it collect for 2 minutes. When I am collecting topo points, I only collect for 5 seconds. I did a 26 acre Lidar mission yesterday ( and recorded some video for a tutorial). I collected all GCP's for 2 minutes. I had 150+ topo shots that I did handheld for 5 seconds each.

[@ryanwallner]

@@DroneMappingTools thanks !

[@chrisalexander2478]

Have you ever had it lose your survey? I did two the other day and everything was fine. Collected about 9 points and when I got back to the office it wasn't on the RS2.

[@DroneMappingTools]

Chris, so now you can do the survey either on the RS2 unit itself (via Web Browser), or the much better option is the using the ReachView 3 app. If you used the RV3 app, the survey is stored on your phone/tablet and not the RS2. So just making sure that is not the case. If that is not the case, I have no idea. I have never had a case where the survey just vanished per say.