Difference in logbook Dekunu and Cloud


There is a difference in the logbook from the Dekunu and the cloud. Even within the cloud there are differences. For example:

Yesterday I did a jump. Dekunu is showing:
Exit altitude: 14.003ft
Deployment 2.238 ft
Duration 58 s

Cloud in My Actions is showing:
Exit altitude: 15.290ft
Deployment 2.610 ft

When viewing the jump:
Exit altitude: 14.650ft
Deployment 2.646 ft
Duration 56 s

Of course this raises questions what is correct. I’m sure the logbook in the dekunu is not correct. Difference between deployment within the cloud is small but the exit altitude is too big.

I understand if the alti has different ways of calculating compared to the cloud. At least have the cloud showing same altitudes and have it send back to the unit to have all values the same. Or update the calculations within the Dekunu so it match the Cloud?

I marked the specific jump for review. This issue is for all the jumps that I have.


Is your landing area 1200ft above sea level? I have the same thing, our DZ is 1300ft ASL so all my jumps in the cloud show exits of around 13-14000ft for a 12k jump and around 16500 for a 15K


Thanks for highlighting this. I have the same issue.

Hi @buzz_lightyear the Cloud is the more accurate one at the moment

the data between the altimeter and the cloud is not the same for the same jump

The exit is 4699m and it is correct
Exit Height : 4699 – 4482 = 217m ?
Vertical distance : 3927-3599 = 328m ?
Freefall time 1,24 – 1,16 = 8sec ?
No Horizontal distance in the altimeter

Deployment Heigjt
Altimer : 7700m

Cloud : 880m

I opened at 1000m and my landing area is 190 m up of sea level

I upload the data to Dekunu


Wow - I still get exactly the same issue in 2023… See my other post… I actually think the values inside Dekunu are the most precise. I did all jumps so far with another analog altimeter - double checking during exit and deployment. Also crosschecked with my colleagues.

I wouldn’t mind if the values are off by a few meters. But f.e. 250m different exit hight is quite something…