# How to run the Map Data Verification Tool The Map Data Verification tool is designed to help Apollo developers detect any issues in their map data collection process before the data is used for HD Map creation. The benefit of using this tool is to ensure that all issues are detected prior to map creation and also ensures that data can be efficiently recollected based on the suggestions in the tool. ## Running the tool In order to run your data on this tool, please follow the steps below: 1. Build Apollo as recommended in the [Build Guide](https://github.com/ApolloAuto/apollo/blob/master/docs/howto/how_to_build_and_release.md) until the `./apollo.sh build` step. 2. Once instde dev docker and after running `./apollo.sh build` please go to the folder `modules/tools/map_datachecker/` 3. Starting the server: ```bash bash server.sh start ``` Note: You should see the following message displayed `Server has been started successfully`. If not, please resolve the errors before trying again 4. Start the record verification: ```bash bash client.sh --stage record_check --cmd start --record_path path_to_record ``` Note: Do not close your terminal window throughout this process. If the verification is successful, you will not see any error messages. 5. Static alignment verification: ```bash bash client.sh --stage static_align --cmd start ``` Note: The window will display the progress of the static alignment. 6. Figure 8 verification: ```bash bash client.sh --stage eight_route --cmd start ``` Note: Your window displays the progress of the Figure 8 verification 7. Laps verification: ```bash bash client.sh --stage loops_check --cmd start ``` Note: Run this command post data collection to check the number of laps 8. Figure 8 verification: This is repeated to verify that the extrinsic parameters have not been changed 9. Static alignment verification: Similar to 5, it is preferable to repeat this verification to ensure high accuracy 10. Stop record verification: ```bash bash client.sh --stage record_check --cmd stop ``` 11. Clean the intermediate results ```bash bash client.sh --stage clean ``` ## Tips 1. The default value of `cmd` is `start` 2. All error messages will be printed to help better prepare your map data. Please follow the error messages exactly as recommended