investigating INS drift is not GPS corrected and INS drift adds up to more than 1000 ft over time

[darkman222]

Reproduction:

-SP mission. One house in the middle, first ring of houses 250 ft, second ring of houses 500ft. STP in the exact middle on the middle house. Make sure its altitude sits on ground level.

 

-F16 with three bags, hot start, so everything is set up correctly

-fly for 2h in any direction, and return and check the waypoint that should be in the exact middle

-check INS drift after 2 hours = 400 ft

-refuel, repeat: INS drift after 4 hours = 1000 ft

-refuel, repeat: INS drift after 6 hours = 1300 ft

This was the maximum INS drift I could measure. If you fly around the STP you can bring it to match better due to paralax. I suspect a higher drift in altitude to contribute to the big visible offset.

Track attached.

https://www.dropbox.com/scl/fi/vb32dm3o09bztxvyvjiry/ins-drift-6-hours.trk?rlkey=50p1ixlfl17rg6b536zremeit&st=7hm9nemo&dl=0

 

 

Edited Wednesday at 05:08 PM by darkman222

[BIGNEWY]

We are investigating this at the moment. HOWEVER, some positional degradation is expected over long periods of time, even with GPS as source. 

thank you 

[skywalker22]

17 hours ago, BIGNEWY said:

We are investigating this at the moment. HOWEVER, some positional degradation is expected over long periods of time, even with GPS as source. 

thank you 

But not as much.