Skydio X10 RTK/PPK metadata overview

Published: Updated:

  1. Skydio
  2. Skydio X10
  3. Skydio X10 Attachments

Each time you take a photo, you capture information that is referred to as metadata. This data is extremely useful when creating 3D reconstructions.

If you are capturing photos using the Skydio X10 RTK/PPK attachment, your files will contain additional metadata. For general Skydio X10 photo metadata, please read the Skydio X10 camera and metadata overview.

[accordion heading="Camera Information"]

Skydio X10 VT300-L and V100-L Wide Camera

EXIF Make

Skydio
VT300-L EXIF Model

VT300-L_93
V100-L EXIF Model

V100-L_93
EXIF FocalLength

7.74 mm
Full resolution (50MP)

8192 x 6144

Pixel size: 1.6 um
1/4 resolution (12MP)

4096 x 3072

Pixel size: 3.2 um

Skydio X10 VT300-Z, VT300-L, and V100-L Narrow Camera

EXIF Make

Skydio
VT300-Z EXIF Model

VT300-Z_50
VT300-L EXIF Model

VT300-L_50
V100-L EXIF Model

V100-L_50
EXIF FocalLength

9.88 mm
Full resolution (50MP)

9248 x 6944

Pixel size: 0.8 um
1/4 resolution (12MP)

4624 x 3472

Pixel size: 1.6 um

Skydio X10 VT300-Z Telephoto Camera

EXIF Make

Skydio
VT300-Z EXIF Model

VT300-Z_13
EXIF FocalLength

35.0 mm
Full resolution (50MP)

8000 x 6000

Pixel size: 0.8 um
1/4 resolution (12MP)

4000 x 3000

Pixel size: 1.6 um

Skydio X10 VT300-Z and VT300-L Thermal Camera

EXIF Make

Skydio
VT300-Z EXIF Model

VT300-Z_40
VT300-L EXIF Model

VT300-L_40
EXIF FocalLength

13.6 mm
Full resolution (50MP)

640 x 512

Pixel size: 12.0 um

[/accordion]

EXIF/XMP/.MRK Tag Descriptions

Relevant metadata information can be found in EXIF, XMP, or .MRK files. To access EXIF or XMP data, use a metadata reader tool such as https://exif.tools/

[accordion heading="EXIF"]

DateTimeOriginal

Date & time of image capture (string)
Make Skydio
Model See above
FocalLength See above

GPSAltitude

WGS84 ellipsoidal
GPSAltitudeRef Set to 0 / ASL
GPSMapDatum

RTK fix or float: RTK Base Station (when receiving RTK corrections the datum will match the datum of the correction service / base station)

All other states: WGS-84

[/accordion]

[accordion heading="XMP"]

GPSTimeOfWeek

Seconds (double) since the start of the GPS time week

GPSWeekNumber

 GPS time of week number (uint32)
GPSAntennaOffsetNorth Baseline (mm, uint32) between antenna phase center and camera sensor projected into North direction
GPSAntennaOffsetEast Baseline (mm, uint32) between antenna phase center and camera sensor projected into East direction
GPSAntennaOffsetUp Baseline (mm, uint32) between antenna phase center and center of camera sensor projected into Up direction (positive)
RTKStatus

GNSS receiver positioning status (uint16)

0 - No positioning
16 - Single point positioning mode
34 - RTK float solution
50 - RTK fixed solution
CameraLineTimeNs

Time (ns, uint32) to readout one line from the image sensor

Used to calculate precise image readout time and line blanking time

  • Image_time = ExposureTime + (LineTime * ImageHeight)
  • Line_blanking_time = LineTime - active_line_time
GpsVerticalAccuracy

Standard deviation (m, float) of positioning results in the vertical direction
GpsHorizontalAccuracy

Standard deviation (m, float) of positioning results in the horizontal direction
GPSStdPosNorth

Standard deviation (m, float) of positioning results in the North direction

Same value is written to GPSStdPosEast and GpsHorizontalAccuracy
GPSStdPosEast

Standard deviation (m, float) of positioning results in the East direction

Same value is written to GPSStdPosNorth and GpsHorizontalAccuracy
GPSStdPosUp

Standard deviation (m, float) of positioning results in the Up direction

Same value is written to GpsVerticalAccuracy
RTKMeanCorrAge

Mean age (ms, uint32) of correction

  • RTK/DGNSS - Differential correction
  • SBAS - Fast correction provided by SBAS satellite
  • PPP - Last received clock or orbit correction message
GPSSource

Source of GNSS data (string)

  • Internal - Drone onboard GNSS
  • Attachment - Drone attachment GNSS
  • VPS - Drone visual positioning system
  • Unknown - GNSS source unknown
Camera.HorizCS

Horizontal coordinate system used by the GNSS receiver

  • RTK fix or float - RTK Base Station
  • All other states - EPSG:4326 (WGS-84)
Camera.VertCS

Vertical coordinate system used by the GNSS receiver

  • Currently always reports ellipsoidal
Camera.GPSXYAccuracy

One sigma (std) horizontal GNSS accuracy (m, rational)

Same value is written to GpsHorizontalAccuracy
Camera.GPSZAccuracy

One sigma (std) vertical GNSS accuracy (m, rational)

Same value is written to GpsVerticalAccuracy

GPSLatitudeRaw

GPSLongitudeRaw

GPSAltitudeRaw

Data as reported by the current active GPS receiver (Internal or Attachment)

Never overwritten or corrected by the drone navigation filter, unlike the corresponding EXIF fields

CameraCorrection

None: no camera correction

RollingShutter: rolling shutter correction
(string)
MetadataVersion

3840 (uint32 representation of 0.0.15.0)

CameraSpeedNED

CameraSpeedFLU

Camera velocity vector (double[3], m/s)

CameraCorrectionGroundPlaneDistance

Camera plane parameters (double, m)

CameraCorrectionGroundPlaneNormalFLU

Camera plane parameter vector (double[3], unit vector)

RelativeAltitude

Altitude relative to launch point (float, m)

[/accordion]

[accordion heading="RINEX Navigation and Observation Files"]

After each scan, Receiver Independent Exchange (RINEX) files are generated. These files are the industry standard for GNSS data and help store GNSS data and metadata.

RINEX files include navigation (.nav) and observation (.obs) files. The file format includes unique flight and time information (e.g., skydio_flight_id).

  • If your scan requires multiple flights, you will have one .nav file and one .obs file per flight
  • The first flight will have a file name ending in 0, the second will end in 1, the third will end in 2, and so on

  • During flight, in a PPK workflow, the drone is only receiving GPS coordinates from the satellites; it is not transmitting them.

  • During flight in an RTK workflow, the drone sends its coordinates over a network.

In addition to the individual flight files, one combined, or concatenated, .nav file and .obs file will be created for the entire scan. These combined files merge all of the flight data into a single .nav file and a single .obs file. The combined files make it easier to process all of the data for the entire scan at once.

Example: One scan that required multiple flights

PPK_NAV_SCAN.nav
PPK_OBS_SCAN.obs
PPK_SBF_SCAN.sbf
Timestamp_SCAN.MRK

First flight

skydio_flight_id_0.nav

skydio_flight_id_0.obs
Second flight

skydio_flight_id_1.nav

skydio_flight_id_1.obs
Third flight

skydio_flight_id_2.nav

skydio_flight_id_2.obs

[/accordion]

[accordion heading="Trigger File (MRK)"]

Each dataset includes a .MRK (Trigger) file, which is a CSV file containing an entry for every photo captured during the scan, a precise timestamp, and high precision GPS information. These files follow the same naming conventions as other scan files.

The .MRK file is provided for legacy compatibility with certain third-party tools.

[note] Since the .MRK file uses a proprietary format, Skydio cannot guarantee future support or compatibility. For the most reliable and future-proof integrations, we recommend using the photo’s EXIF and XMP metadata instead of relying on the .MRK file. [/note]

The .MRK file columns are defined as follows:

Column

 Field Example

A

Dataset photo number

1
B

GPS time

Time of week (TOW) (s, 6 decimal places)

421507.260000
C

GPS time

Week number

[2305]
D

Antenna offset (mm, int) North (similar to XMP GPSAntennaOffsetNorth)

-218,N
E

Antenna offset (mm, int) East (similar to XMP GPSAntennaOffsetEast)

-131,E
F

Antenna offset (mm, int) Vertical (similar to XMP GPSAntennaOffsetUp except negated)

12,V
G

GNSS latitude (degrees, with mm resolution, 8 decimal places)

37.53370452,lat
H

GNSS longitude (degrees, with mm resolution, 8 decimal places)

-122.33230888,lon
I

GNSS elevation (ellipsoidal, m, 3 decimal places)

200.599,Ellh
J

GPSStdPosNorth

Field as defined in the XMP section (3 decimal places)

3.070
K

GPSStdPosEast

Field as defined in the XMP section (3 decimal places)

3.070
L

GPSStdPosUp

Field as defined in the XMP section (3 decimal places)

6.210
M RTKStatus as defined in the XMP section 50,Q

Example entries in a trigger file:

CS_X10_RTK_PPK_metadata_trigger_file_example.png

[/accordion]

[accordion heading="Pix4D Files"]

[note] These files utilize a third-party proprietary format. Skydio cannot guarantee future support or forward/backward compatibility with this format. We do not recommend its use for third-party integrations. We recommend using the photo’s EXIF and XMP metadata instead. [/note] 

Pix4D_Mapper_geolocation.csv

A file that includes metadata specifically for use in PIX4DMapper.

[note]Always keep your system up-to-date. If your drone is running a software version that is 34.1.106 or earlier, the file name will be Pix4D_geolocation.csv. [/note]

Column Field Definition

Example

A

Name

Photo file name

S1055104.JPG
B Latitude

GNSS latitude (degrees)

 37.533249033333334
C Longitude

GNSS longitude (degrees)

 -122.33152521666666
D Height

WGS84 ellipsoidal height (m)

Drone software versions 34.1.106 or earlier: EGM96 Geodetic height (MSL) in Pix4D_geolocation.csv

 171.008
E Omega Gimbal roll (degrees) -0.02339437106854344
F Phi Gimbal pitch (degrees) -0.014712609062578678
G Kappa Gimbal yaw (degrees) -39.9387623714572

Example Pix4D_Mapper_geolocation.csv file:

CS_X10_RTK_PPK_metadata_pixmapper_file_example.png

Pix4D_Matic_geolocation.csv

A file that includes metadata specifically for use in PIX4DMatic. The file format is similar to Pix4D_Mapper_geolocation.csv except the Omega/Phi/Kappa fields are replaced with Roll/Pitch/Yaw respectively.

[/accordion]

[accordion heading="Septentrio Binary File (SBF)"]

A Septentrio Binary File (.sbf) is a proprietary binary file format used to store raw GNSS data. These files contain the raw GNSS data in a binary format designed for high-precision positioning and post-processing tasks.

An SBF is created for each flight and each scan, and it follows the same naming conventions as trigger (.MRK) files.

[/accordion]

[accordion heading="ANTEX File"]

An Antenna Exchange Format (ANTEX) file is a standardized file format used to store calibration data for GNSS antennas.

The RTK/PPK attachment generates an ANTEX file (.atx) named M9HCT_Skydio.atx, which contains calibrated antenna phase center correction metadata. This file is compliant with version 1.4 of the ANTEX standard.

[/accordion]

Example folder and file structure

CS_X10_RTK_PPK_metadata_example_scan_files.png

Explore More

Skydio X10 camera and metadata overview
Getting started with the RTK/PPK attachment
How to process Skydio X10 RTK/PPK data

 

 

Skydio Inc., A0558

Was this article helpful?