Uploading a PPK Survey From an Autel EVO II RTK


If you fly an Autel Evo RTK II V1 or V2, you can access Propeller's high-accuracy survey processing workflow. This handles both the PPK correction of your drone's GPS observations and the processing of your images to create a 3D model of your site.

Note: This article references the PPK workflow. If you're looking to process data with our standard dataset workflow, here are the step-by-step instructions for the Standard Workflow.

Required Inputs

  • One or more drone flights with at least 10 JPEG images each

  • Two GPS observation data files from each drone flight: 

    • [FlightName]_PPKRAW.bin

    • [FlightName]_Timestamp.mrk

  • One AeroPoint flight that has not been submitted for processing. You will complete the processing step as part of your dataset upload. 

If you already processed your AeroPoint flight, duplicate it in your AeroPoints Dashboard or make a copy during the data upload process to create an unprocessed copy.

Before you start

Make sure you have created a new site, or know which site you want to add your survey to by choosing it in the dropdown menu.

Create_a_new_site.png

Select Photogrammetry survey processing for the data type you're submitting.

DataUpload_PhotogrammetrySurveyProcessing.png

Corrections

Next, select the Corrections method you want to use.

  • Propeller PPK will merge your GNSS files with the Propeller Corrections Network, Known Point data, or a provided RINEX file to ensure the highest levels of accuracy.
  • Choose Use my drone photos if you want to upload your drone photos, including any high accuracy geotags, if applicable.

DataUpload_use_PCN.png

Selecting photos for upload

The data captured during your flight is organized into folders on your SD card. Navigate to a folder(s) that is named to include the corresponding date for your survey. Upon examination, you will find that this folder contains all the imagery and the survey files (.bin, .mrk, and .obs) for your flight. Navigate back to the root and drag the entire survey data folder into the uploader.

If you conducted multiple flights, all folders must be added for each completed flight. 

Validation 

Your photos are scanned and validated in the following four categories. Photos must pass these requirements to be properly processed. 

Your file collection
  Your drone
  Individual images
PPK files
Minimum 10 images  
Drone camera is recommended
  Compatible geotag Files have the required metadata
           
Same aspect ratio   PPK drone is registered   Aspect ratio Files must be unique
           
Camera course alignment       Motion blur  
           
Single connected area       ISO  
           
        File name is less than 255 characters  
           
        Minimum 8 megapixels  
           
        Files above size limit (75 K)  

 

For more information on these validations, please see our pilot help materials

Once the selected files have been validated, a map will appear with the location of your photos and survey area. 

When all photos are displayed, click NEXT to proceed.

Dataset details

Set the dataset name and capture date. Adding the capture date and time will place each survey chronologically on the Timeline View feature. Click NEXT.

The date and time defaults to the timestamp on the first uploaded photo.

Adding AeroPoint survey data

Next, submit an AeroPoint survey. You can choose from two options:

  • AeroPoints, or
  • AeroPoints and a .csv file

To learn more about submitting ground control, check out our article “Submitting Ground Control/Checkpoints with Your Survey Dataset.”


Data Upload Choose AeroPoints for Ground Control.png

If you add a survey to an existing site, the site’s coordinate reference system will be displayed here.

Set_Coordinate_Reference_System.png

Choose the AeroPoint survey from the list of available AeroPoint captures.

To submit PPK data, you must select an unprocessed AeroPoint survey from your AeroPoint captures. 

Those outlined in red are already processed but can be duplicated if selected.

Select processing method

Three ways to process data

1. Propeller Corrections Network

This method uses the Propeller Corrections Network to obtain globally accurate coordinates.
PCN_Method.png

Submitted ground control and checkpoints using the Propeller Corrections Network

From the dropdown, assign each AeroPoint in your survey as either a Ground control point or checkpoint. You can also exclude it from your survey. 

The number of AeroPoints you select as ground control points vs. checkpoints depends on the area and undulations covered by the survey. Typically three (preferably five) AeroPoints as ground control points and the remainder as checkpoints are sufficient.

2. Known Point Method

Here you will select an AeroPoint that has a known location and enter its coordinates. In these screen captures, you are uploading to a site based on a published coordinate system, so the Global Survey Benchmark method is used. You will use the Local Survey Benchmark method if you are uploading to a site based on a local grid calibration. If you use a known point to process your AeroPoint survey, be sure it is selected as a ground control point unless it is not in the survey area.

DataUpload_KnownPoint.png

3. RINEX Upload

This method uses RINEX GNSS observation data from a base station within 40 km covering the time period of the survey.

DataUpload_RINEX_Method.png

To learn more, check out our On-demand training videos.

Comments about your GCPs

This is an optional box where you can provide more information regarding your GCPs to our data team. For example, it’s helpful to know if anything unusual happened during your survey, such as if the AeroPoint was accidentally moved or destroyed during capture.

Uploading_Comments.png
Outputs

Elevation model filter

Elevation model filters remove undesired artifacts such as trees, buildings, equipment, and vehicles from the digital elevation model output. 

You can select No filter or from the other available filter settings as part of the output configuration.

We recommend using either the No Filter or Equipment filter and combining this tool with Terrain Cleanups to ensure you only remove items that would affect your measurements.  

DataUpload_ChooseFilter.png

Configure outputs

This is a list of the output files that will be produced as part of the final dataset. Files can be found on the Platform and downloaded from the Viewer.

DataUpload_ConfigureOutputs.png

Summary and Upload Progress

Dataset details

Please review your dataset for accuracy before you click SUBMIT.

Uploading_Summary.png

1. Dataset details

General information about the dataset you are submitting, including:

  • Site name
  • Date and time flown
  • Total gigapixels and photos
  • Type of upload

2. Corrections

Select the Corrections method you want to use for you upload.

3. Ground control

  • Type and number of GCPs and checkpoints

4. Processing outputs

  • Files included in the platform
  • Downloadable files

5. Quality assurance settings

This guides how many QA checks are made on your survey. Generally, the stricter the chosen QA, the longer the turnaround time.

6. Dataset credits

Total number of credits used to process your data.

Upload progress

After clicking Submit, your dataset will begin its upload, with the percentage complete, the number of files uploaded, and an estimated completion time. It is important that this browser window stays open until the dataset is fully submitted. If your upload is interrupted for any reason, you can resume the process within 24 hours from when you started it.

DataUpload_ProgressBar.png

DataUpload_UploadComplete.png


I still can't do it!

We wrote these articles to equip you with everything you need to get the job done on your own, but we understand that sometimes this isn't sufficient.

If you're stuck, you can connect with our support team by clicking the support button on the top right corner of your user portal.

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