Welcome DJI Spark Pilot!
Jump in and join our free Spark community today!
Sign up

what is the difference between IMU Altitude and VPS Altitude

NRRTRAINS

Well-Known Member
Join
Jul 25, 2018
Messages
233
Loc
Staten Island, New York
what is the difference between IMU Altitude and VPS Altitude and why does IMU go to negative when i get closer to ground zero ( where i take off from ) . why does VPS Altitude lose telemetry an go to NA at times or is that just what happens too everyone or just my Spark .
thank you
 
The VPS (Visual Positioning System) uses the camera on the bottom and the bottom IR sensors to about 25 feet until the Spark is high enough for the barometer to kick in and measure the altitude.

This may happen depending on the light conditions or pattern on the ground when flying low.
 
The VPS (Visual Positioning System) uses the camera on the bottom and the bottom IR sensors to about 25 feet until the Spark is high enough for the barometer to kick in and measure the altitude.

This may happen depending on the light conditions or pattern on the ground when flying low.
thank you
 
IMU (Intertial Measurement Unit) Altitude, as the name suggests uses the accelerometer, gyroscope and barometer to measure the altitude of the AC. It takes the takeoff point as 0 and depending upon ascent or descent from that point it shows the altitude as +ve or -ve. The negative value you are seeing is probably because you are landing slightly below the takeoff point. It may happen if the ground is not flat or you took off from an elevated surface (your palm for example).

VPS (Visual Positioning System) Altitude uses the bottom sensors (camera and IR sensor) to detect "ground" within 0-26ft (0-8m). So above 8m, it will be displayed as NA in your flight logs. Its main function is to work as an obstacle detection sensor and tell the drone that it is approaching ground so that the descent speed is reduced at the time of landing.
 
Last edited:
You will see a tiny flashing icon when it is active next to the telemetry reading for “Height”
 
IMU (Intertial Measurement Unit) Altitude, as the name suggests uses the accelerometer, gyroscope and barometer to measure the altitude of the AC. It takes the takeoff point as 0 and depending upon ascent or descent from that point it shows the altitude as +ve or -ve. The negative value you are seeing is probably because you are landing slightly below the takeoff point. It may happen if the ground is not flat or you took off from an elevated surface (your palm for example).

VPS (Visual Positioning System) Altitude uses the bottom sensors (camera and IR sensor) to detect "ground" within 0-26ft (0-8m). So above 8m, it will be displayed as NA in your flight logs. Its main function is to work as an obstacle detection sensor and tell the drone that it is approaching ground so that the descent speed is reduced at the time of landing.
thank you
 
  • Like
Reactions: nilanjan118
why does VPS Altitude lose telemetry an go to NA at times or is that just what happens too everyone or just my Spark
That happens when the downward sensors are too far away from the ground (or nearest obstacle below the Spark) to detect it.
 
The VPS (Visual Positioning System) uses the camera on the bottom and the bottom IR sensors to about 25 feet until the Spark is high enough for the barometer to kick in and measure the altitude.
FWIW, the barometer doesn't kick in where the VPS leaves off. It's able to start estimating the height as soon as the Spark takes off.
 
Make sure the bottom sensors are clean. I very slightly miss-aligned a skin and that was the result. Since then I use a clean hard surface for take-off and usually hand land mine. it wouldn't take much to cause bizarre flight behavior
 
FWIW, the barometer doesn't kick in where the VPS leaves off. It's able to start estimating the height as soon as the Spark takes off.

Thank you.
 
Bonjour j'ai un problème d'affichage d'altitude dans dji go 4 avec mon étincelle. En effet, au-delà des 10 m (Vps), les valeurs d’affichage changent constamment, oscillant entre la bonne valeur (par exemple 15 m) et les valeurs comprises entre 2 et 3 m d’altitude. J'ai tout essayé (réinstallation avec nettoyage "à la main", valeur d'usine, downgrade, upgrade, sur plusieurs smartphones donc un s7 "vierge" où je n'avais installé que l'application d'origine) ... mais rien n'y est. Par contre tout fonctionne parfaitement si j'utilise l'application Litchi.20191010_202109.jpg20191010_202038.jpg
 

Members online

No members online now.

Forum statistics

Threads
14,593
Messages
118,799
Members
17,987
Latest member
csdisme