Not correct Velocity published topic from the hector_localization stack when fusing IMU and Pressure_height

edit

Hi

Im doing some underwater UUV Gazebo simulation and would like to use the

hector_pose_estimation

package to fuse IMU and Fluid pressure sensors input for velocity estimation. Im using this launch file

<?xml version="1.0"?>
<launch>
  <node pkg="hector_pose_estimation" type="pose_estimation" name="hector_pose_estimation">
    <remap from="raw_imu" to="/rexrov2/imu" />
    <remap from="pressure_height" to="/pressure_height" />
    <param name="base_footprint" value="/rexrov2/base_footprint"/> 
    <param name="base_link" value="/rexrov2/base_link"/> 
    <param name="stabilized_frame" value="/rexrov2/base_stabilized"/>
    <param name="world_frame" value="world"/>
    <param name="child_frame" value="rexrov2/base_link"/> 

  </node>
</launch>

And the velocity and pose output are followings. Velocity output:

header: 
  seq: 2152
  stamp: 
    secs: 67
    nsecs: 824000000
  frame_id: "world"
vector: 
  x: 0.0
  y: 0.0
  z: -0.000197583960972

Pose output

header:    seq: 329   stamp: 
 secs: 781
 nsecs: 118000000   frame_id: "nav" pose:    position: 
   x: 0.0
   y: 0.0
   z: -1.64102132948e-09   
 orientation: 
    x: -8.80621330591e-06
    y: 0.000294167493465
    z: 3.71623915803e-14
    w: 0.999999956694

Which are not correct as when move the robot the position and velocity in x and y should change and not be zero.Are they zero because the the pressure topic has only the z attitude and z,y component of the pressure are zero so that package think that the robot is not moving? How to fix it?