# Parking underground

## Dealing with bad GPS signal

Sometimes shared vehicles are parked underground or in an area with high rise buildings. In both conditions GPS performance of the cloudboxx can be bad and the location of the vehicle in the app can be off by several hundreds of meters because of a bad gps fix or none at all. 

Although the car might be parked in it's proper home zone, the app reports it's not and the user cannot end its reservation. To fix these problems the position of the car can be overwritten by a predefined position under certain circumstances. The **position quality configuration** can be done in Control Center.

### Configuration parameters

The configuration takes 4 parameters.

1. **max meter limit:** this is the threshold of how many meters the car should have driven since last receiving a correct GPS position. If this limit is reached (together with the HDOP limit) the position is overwritten. Recommended value to start with: 500
2. **HDOP:** HDOP stands for horizontal dilution of precision. HDOP is a measure of the confidence level of the last GPS fix. The lower this number the more confident and the better the last GPS position was. If a GPS fix has a higher HDOP than this parameter (and the max meter limit is reached) the position is overwritten. Recommended value: 1
3. **latitude:** latitude of the overwrite position
4. **longitude:** longitude of the overwrite position

The overwrite position is defined by the coordinates in latitude and longitude. You can manually enter these value are select a position on the map

### Configuration in Control Center <a href="#configuration-in-control-center" id="configuration-in-control-center"></a>

The position quality configuration is set on the level of a physical vehicle. To add a configuration for a certain vehicle go in Control Center to "vehicles", select the vehicle and go to settings. Here you can add a configuration, remove it and edit the parameters.

### &#x20;<a href="#configuration-parameters" id="configuration-parameters"></a>

## Starting and stopping a reservation while the in-car hardware has no signal

{% hint style="info" %}
Vehicles that are parked underground cannot be used reliably with the RFID cards for which the in-car hardware needs to be connected to the internet to work
{% endhint %}

### Starting reservation

It's not necessary for the in-car hardware to be connected to a network for a reservation to be started. However the smartphone of the user does need a working internet connection. Consider configuring a warning for users so they start the reservation **before** entering the underground parking. You can read more about that [here](https://handbook.themobilityfactory.coop/tmf-platform-documentation/notifying-users/warning-for-zones-with-poor-cellular-network-coverage).&#x20;

For the user to be able unlock the vehicle underground the smartphone of the app on the user's smartphone connects to the in-car hardware directly via bluetooth. The app needs to be granted the correct permissions for this to work. The app asks to grant these permissions.&#x20;

### Ending reservation

It's not necessary for the in-car hardware to be connected to a network for a reservation to be ended if: the TMF servers have received an update of the car during the trip and/or the app on the user's smartphone sends the trip data to the TMF servers which the app obtained via the bluetooth connection. In rare circumstances this the hardware might have not come online during the trip usually indicating towards an issue with the in-car hardware antenna. If this happens the reservation cannot be ended as the server does not have the necessary data.&#x20;