# Native Barometer and GPS height estimation bad

Source: https://forum.modalai.com/topic/3580/native-barometer-and-gps-height-estimation-bad
Category: Development Drones (https://forum.modalai.com/category/44/development-drones)
Tags: px4-dev-kit
Posted: 2024-06-24 19:46:30 UTC by Jeffrey Mao
Replies: 4 · Views: 2072

## Jeffrey Mao · 2024-06-24 19:46:30 UTC

Hi Modalai,

Recently we tried flying with the native barometer/recommended 3DR GPS on the website and found the performance was quite bad comapred to other products

https://www.modalai.com/products/m10000640

Do you have any suggestions on how to improve them or an alternative product to do no Vision based height estimation

## Reply by Eric Katzfey (ModalAI staff) · 2024-06-24 21:09:20 UTC

@Jeffrey-Mao You shouldn't have an issue with the barometer. But the GPS does suffer performance issues due to it's plastic mount, proximity to WiFi antenna, and proximity to RC antenna. We are currently designing a new way to mount things such that the GPS performance does not suffer so much.

## Reply by Jeffrey Mao · 2024-06-25 01:34:29 UTC (in reply to Eric Katzfey)

@Eric-Katzfey thanks for the quick response. Yeah personall we ended up mounting the GPS further up with a pole in a custom design. Do you guys have a link to the px4 parameters you use with the barometer onboard the Voxl2 or does it need some sort of calibration?

## Reply by Eric Katzfey (ModalAI staff) · 2024-06-25 15:37:33 UTC (in reply to Jeffrey Mao)

@Jeffrey-Mao We haven't had problems with the barometer nor have I heard of any users having an issue with it. It does not need any calibration. Are you using it on a custom drone? If so, do you have a way to shield it from sunlight? That is a common issue with barometers, they are sensitive to sunlight. Can you share a log file when it is performing poorly? You could also add a distance sensor to your drone.

## Reply by Vinny (ModalAI staff) · 2024-06-26 17:10:41 UTC (in reply to Jeffrey Mao)

HI @Jeffrey-Mao 
Another consideration for baro is active airflow. We typically provide a "cap" on our baros in our drones or flight-decks to ensure it is not exposed to sunlight (as Eric stated) but also active airflow which can show up like air pressure noise.
Our 3D models repository has a 3D file of this cap, in this case for FlightCore to give you an example:
https://storage.googleapis.com/modalai_public/modal_drawings/Flight_Core_Barometer_Cap.STEP
Hope this helps.