# How to get odom data with respect to map frame?

**URL:** <https://get-help.theconstruct.ai/t/how-to-get-odom-data-with-respect-to-map-frame/8136>\
**Category:** ROS Navigation In 5 Days\
**Created:** [February 8, 2021, 11:25pm UTC](https://get-help.theconstruct.ai/t/how-to-get-odom-data-with-respect-to-map-frame/8136 "2021-02-08T23:25:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Zilin\_Li](https://get-help.theconstruct.ai/letter_avatar_proxy/v4/letter/z/c57346/32.png) [@Zilin\_Li](https://get-help.theconstruct.ai/u/Zilin_Li)\
**Post date:** [February 8, 2021, 11:25pm UTC](https://get-help.theconstruct.ai/t/how-to-get-odom-data-with-respect-to-map-frame/8136/1 "2021-02-08T23:25:20Z")

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Hello All,

I know that normally odom data is with respect to /dom frame and amcl node publishes a transform between the /map and /odom frame by default. If we start the amcl node for a while and then run the rostopic echo /dom again, does the odom data we got is with respect to the /map frame right now? If not, how can I get the odom data with respect to the /map frame? Appreciate anyone who could help me!

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**Author:** ![albertoezquerro](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/albertoezquerro/32/7031_2.png) [@albertoezquerro](https://get-help.theconstruct.ai/u/albertoezquerro)\
**Post date:** [February 9, 2021, 9:15am UTC](https://get-help.theconstruct.ai/t/how-to-get-odom-data-with-respect-to-map-frame/8136/2 "2021-02-09T09:15:15Z")

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Hello @Zilin_Li ,

Actually, the odometry data is published w.r.t the base frame of the robot, typically **base\_link** or **base\_footprint**. If you want to know the odometry data w.r.t the map frame, you can calculate the transform between them (ie. using the **tf\_echo** tool):

`rosrun tf tf_echo odom map`

Hope this helps,