GNSS Compare

The purpose of GNSS Compare is to make the life of developers and researchers easier. It’s an easy to use and easy to extend Android-based framework for calculating the Position, Velocity and Time (PVT) based on the raw GNSS measurements.

GNSS Compare is the winning Android application developed by the

(https://gnss-compare.readthedocs.io/en/latest/team.html) as part of the internal European Space Agency (ESA) competition called Galileo Smartphone App Challenge introduced in October 2017. Furthermore, the competition was supported by the European Commission (EC) and European GNSS Agency (GSA). The Challenge was about creating a smartphone application, which will allow the user to choose which satellite constellation to use for Position, Velocity, and Time (PVT) estimation. The aim was to increase the awareness about the European Union’s Galileo satellite navigation programme and also to allow users from common public to view and use Galileo signals.

The current features of GNSS Compare include:

- Open-source code on

https://github.com/TheGalfins/GNSS_Compare

-

https://gnss-compare.readthedocs.io

- Modular software framework for extending GNSS Compare’s PVT algorithms

- Supported GNSS constellations: Galileo only, GPS only, Galileo&GPS combined

- Support for dual-frequency receivers

- Available PVT estimators: Weighted Least Squares, Extended Kalman Filter

- Data logging formats: Simple Logger (UTC timestamp, X, Y, Z), NMEA (UTC timestamp, lat, lon, alt, CN0), Raw GNSS measurements (Google’s GnssLogger format)

- note: all calculations are initialized with phone's

location

.

The list of Galileo compatible phones can be found

https://www.usegalileo.eu/EN/inner.html#data=smartphone.

The list of phones supporting Android raw GNSS measurements can be found

https://developer.android.com/guide/topics/sensors/gnss.

So far we’ve been testing the application on:

- Samsung Galaxy S8

- Samsung Galaxy S8+

- Xiaomi MI8

If you want to be kept up to date with our updates, you can sign up to our

: https://goo.gl/forms/S0J0Kp4W5jWZYJCm1

Acknowledgements:

GNSS Compare’s developers would like to thank the European Space Agency for the continuous support throughout the development of this application. Especially we would like to mention the ESA employees that shared their experience and knowledge regarding the Dual-Frequency aspects: Paolo Crosta, Nityaporn Sirikan, Gaetano Galluzzo, Paolo Zoccarato, and Tim Watterton.

GNSS Compare的目的是让开发人员和研究人员的生活更轻松。它是一个易于使用且易于扩展的基于Android的框架，用于根据原始GNSS测量计算位置，速度和时间（PVT）。

GNSS Compare是由

开发的获奖Android应用程序（https：// gnss-compare .readthedocs.io / en / latest / team.html）作为2017年10月推出的名为Galileo Smartphone App Challenge的欧洲航天局（ESA）内部竞赛的一部分。此外，该竞赛得到了欧洲委员会（EC）和欧洲委员会的支持。 GNSS机构（GSA）。挑战是关于创建一个智能手机应用程序，它将允许用户选择用于位置，速度和时间（PVT）估计的卫星星座。其目的是提高对欧盟伽利略卫星导航计划的认识，并允许公众用户查看和使用伽利略信号。

GNSS Compare的当前功能包括：

-

上的开源代码https://github.com/TheGalfins/GNSS_Compare

-

https://gnss-compare.readthedocs.io

- 模块化软件框架，用于扩展GNSS Compare的PVT算法

- 支持的GNSS星座：仅限伽利略，仅限GPS，伽利略和GPS组合

- 支持双频接收器

- 可用的PVT估算器：加权最小二乘法，扩展卡尔曼滤波器

- 数据记录格式：简单记录器（UTC时间戳，X，Y，Z），NMEA（UTC时间戳，lat，lon，alt，CN0），原始GNSS测量（Google的GnssLogger格式）

- 注意：所有计算都是通过电话的