How to start Post Processing Kinematic (PPK) flight.

Issue

How to start Post Processing Kinematic (PPK) flight.

Answer

Please refer to the explanations below.

Explanation

When you want to use PPK, you always need a reference point on the jobsite. 

Overview PPK properties:

• SC Edge logs GNSS corrections throughout the flight duration.
• SC Edge needs to be set up at the jobsite.
• You need an external known point OR use the RTK receiver in the SC Edge to localize it and use that as a known point to log the correction data.

It’s important to make sure your ‘known point’ is a GNSS-friendly location so your signal doesn’t get interrupted. 

You can log GNSS correction data in two ways. You can use...

1. PPK localization on a known point for localization like a survey nail or the data of a GNSS rover

When you use localization on a known point, there are two options.
You can:

A. center the tripod over a survey nail,
B. or retrieve the coordinates with a GNSS rover. 

In both cases, you enter those coordinates in the SC Edge.

Option A: Centered over a survey nail

1. Place the survey tripod over a known point: a survey nail or another mark.

2. Use a tribrach with optical plummet.

Tribrach with optical plummet

A tribrach is an attachment plate used to attach a surveying instrument to a tripod, for example a theodolite, total station, GNSS antenna or target. A tribrach allows the survey instrument to be placed repeatedly in the same position over a surveying marker point with mm precision, by loosening and re-tightening a lock to adjust the instrument base in a horizontal plane.

3. Add the distance from the survey nail to the base of the SC Edge to determine the ‘Pole height’.

Option B: Retrieve coordinates with GNSS rover

1.  Place the rover on the tribrach.

2. Measure the coordinates of the screw adapter where you are going to place the SC Edge. 

3. Fill in the coordinates in the SC Edge interface.

TIP

Make sure to use latitude & longitude in WGS84 coordinates, with ellipsoidal height.

4. Place the SC Edge on exactly the same screw, so that the height is correct with the base of the SC Edge.

Enter coordinates in the SC Edge

Now that we have placed the survey tripod over a known point or retrieved the coordinates with a GNSS rover, we have to enter those coordinates in the SC Edge.

1. Launch the Edge1 app (Apple) or enter IP code 10.42.0.1 in browser (Android).

2. Select ‘Base Station’.

3. Select ‘Input position manually’.

4. Fill in the different coordinates and information.

5. Turn on the PPK logging.

6. You are now logging your GNSS correction data!

2. PPK localization using internal network RTK receiver of the SC Edge

Wait… Didn’t we just choose a PPK flight? Why still use RTK as a way to locate the SC Edge as a known reference point?

… The internet connection is very spotty: you are in a remote location, there are a lot of trees or structures near,… and you can see your internet connection (4G) on your phone go in and out… In this case, it’s safer to have your RTK logging on a set object (the SC Edge) than on a moving object (drone controller) that might lose connection.

For this option you'll need...

• A RTK SIM card to insert into SC Edge
• An operational RTK account from your local GNSS/NTRIP provider: depending on your location, this can be a free or a paid subscription.

1. Insert the RTK SIM card into the SC Edge.

2. Launch the Edge1 app (Apple) or enter IP code 10.42.0.1 in browser (Android).

3. Select ‘Base Station’.

4. Select ‘Acquire position via NTRIP’.

5. Select your applicable NTRIP account.

Attention!

NTRIP RTK account needs to be registered in Settings menu prior to logging.

SAPOS = German NTRIP system

6. You're all set! Your PPK data is logging.