GNSS Base Stations
GNSS base stations on the ground can record satellite observations during flight and can be used to increase the relative and absolute accuracy of the photo geotags.
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GNSS base stations on the ground can record satellite observations during flight and can be used to increase the relative and absolute accuracy of the photo geotags.
Last updated
The Astro and later versions of the Alta X come pre-integrated with a Freefly RTK unit. Just add a Freefly RTK GPS (sold separately) to enable centimeter-level positioning data.
Instructions for RTK with the Pilot Pro and Astro or Alta X can be found on our Pilot Pro wiki through the link below
Configures output to be compatible with Astro.
Install SIM card (optional).
Open ReachView 3 app (iOS or Android). Connect to RS2. via wifi and open the Reach Panel (192.168.42.1)
Logging > Raw Data > Settings:
RINEX 3.03
Satellite systems: check all
Logging Interval: 1s
This log is for OPUS: Checked
Measured height, m: [Height of your pole]
Automatically start recording when receiver is turned on: Optional. We use this.
Logging > Position > Settings:
Automatically start recording when receiver is turned on: Optional. We use this.
Logging > Base Correction > Settings:
Automatically start recording when receiver is turned on: Optional. We use this.
Correction input (optional, requires network connection via wifi or cellular). This is not necessary for high accuracy results, but a live correction feed will allow another avenue of finding the GPS's position to high accuracy. With network corrections, the GPS absolute accuracy should increase to cm level.
Enter credentials.
Perform this procedure before flying Astro.
Install Reach R2S on pole.
Optional: Position pole over GCP
Connect to RS2 via wifi
Open EmlidView 3 app. Logging.
stop logging if its running
Download the RINEX file and the pos file if desired.
Follow manual to enable recording either on boot or on demand. To download the data, stop recording, then go to the data store and select the correct file. Pick the option to convert and download and choose observables and ephermis, and RINEX 3.03 or 3.04 format.
(More details coming soon)
Known Issue: When you click Convert & Download, the Trimble crashes. You can only download without converting for now. Jeremy thinks it might be because of low storage space and reseting might help. Let's give it a shot.
Use the NUWA app and connect to the Tersus Oscar. Go to SURVEY tab, and select static survey. Enter the duration to be max (1440 minx), interval 1hz, RINEX format 3.04, select mount type, and enter the antenna height on the given mount. Select start, and make sure the timer starts counting.
When done, reconnect with the NUWA app and go back to static survey, and then stop the recording. Use a USB-mini cable and plug into the bottom of the unit. Download the rinex files from the RECORD virtual USB drive that appears.
Astro uses the uBlox F9P as its internal GPS unit.
Open AMC on PC ()
via the Herelink's wifi hotspot
If there is no telemetry in AMC even after connecting to the hotspot, change .
With the Astro's LTE connectivity, you no longer need your own ground station to have increased accuracy on the Astro. The Astro can use cell connectivity to pull in corrections from existing ground stations in order to correct it's own GPS signal. The NTRIP app can be downloaded from the For more information about the setup of your NTRIP provider, please refer to
The Astro comes with a trial sim. For extended usage, you will need to on the Astro with your own plan
Generally, PPK can be performed with RINEX output from any GNSS base station that records at minimum L1 and L2 GPS observations (see ). However, photo geotag accuracy after PPK corrections is limited to the accuracy to which the base's position is known. Therefore, it may be worth purchasing a base with additional capabilities (e.g. SIM for CORS RTK, receives more channels, advanced multipath processing, etc) when you cannot put the base on a pre-surveyed GCP.
For the base stations listed below, the settings and procedures provided will ensure output is compatible with the . The PPK workflow can be found.
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Follow .
Power on RS2. Make sure booting is complete () takes about a minute. It will begin logging automatically.
