# Optical flow example data \[indoor local position estimate\]

**URL:** <https://discuss.px4.io/t/optical-flow-example-data-indoor-local-position-estimate/39374>\
**Category:** PX4 Autopilot\
**Created:** [June 22, 2024, 3:43pm UTC](https://discuss.px4.io/t/optical-flow-example-data-indoor-local-position-estimate/39374 "2024-06-22T15:43:47Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Mohamd\_Ayman](https://discuss.px4.io/user_avatar/discuss.px4.io/mohamd_ayman/32/16612_2.png) [@Mohamd\_Ayman](https://discuss.px4.io/u/Mohamd_Ayman)\
**Post date:** [June 22, 2024, 3:43pm UTC](https://discuss.px4.io/t/optical-flow-example-data-indoor-local-position-estimate/39374/1 "2024-06-22T15:43:48Z")

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Could someone please give an example of a valid optical flow messages received by their px4?  
I’m using a PMW3901 optical flow sensor connected to an RPI, the Optical\_flow\_rad messages are sent using mavlink to achieve an indoor local position estimate, which works just fine for the first 2 seconds of moving, then the failsafe activates because it loses “the local position estimate”.

those are my logs as timestamp, flow\_x, flow\_y  
[https://codeshare.io/Yz7JBb](https://codeshare.io/Yz7JBb)

really appreciate any help.