Precision Landing with GPS Module

Hi, I am planning to change firmware to make precision landing while GPS exists with aruco markers flying with quadplane, so here some PR is requested for arduplane in precision landing using IRLock : PR link
So here are steps that I think I have to do, if it’s not enough could you,please?

  1. Roughly implement precision landing as above.
  2. Send the aruco coordinates to ardupilot with /mavros/landing_target/raw
  3. Implement coordinates to precision landing code.
    I know it is easy to think and write here but I have questiones about the steps:
  • Is precision_landing.cpp is changable wrt ardupilot algorithm if aruco coordinates are sent?
  • I changed apm_config.yaml parameter to listen tfs that I construct and I tried to send the coordinates through the /mavros/landing_target/raw but I didn’t see topic in rviz and rqt_graph then I changed source code of mavros_extras in function argument as true but nothing changed I just saw the topic when I write rostopic list into terminal but it’s visible because I remap my topic to /mavros/landing_target/raw in launch file. I tried to listen this topic making rostopic echo /mavros/landing_target/raw but nothing happened. Then I directly change the if part of the source code to true (listen_lt changed to true I mean) then I can listen when I make rostopic echo again bu I didn’t see the topic in rviz. So there is a issue here I dunno why. I tried the other topics but nothing changed, does problem cause for firmware?
  • When using /mavros/landing_target/raw those datas where are they used in firmware side (which source code takes the datas from this topic) when it is used for precision landing?
  • Can I implement datas to precision_landing.cpp , does it cause a big problem and if not how can I implement those? Actually I am looking for smilar source code from copter to use topic datas as precision landing but I didn’t find.
  • I have done for aruco detection, taking its coordinates , constructing tf , sending datas to topic but /mavros/landing_target/raw is enough for ROS side? Because mavros make convertion to mavlink messages.
  • Also , I have a plan to use precision landing with GPS that’s why I have o add or change the lua scripts from firmware If I understand right. If I am wrong could you correct me?

This will be first try so I may be wrong or not enough to do that right now but I need guidence to start somewhere.