|
|
|
|
# GPS Measurement Tools
|
|
|
|
|
|
|
|
|
|
The GNSS Measurement Tools code is provided for you to:
|
|
|
|
|
|
|
|
|
|
* read data from GnssLogger App,
|
|
|
|
|
* compute and visualize pseudoranges,
|
|
|
|
|
* compute weighted least squares position and velocity,
|
|
|
|
|
* view and analyze carrier phase (if it is present in the log file).
|
|
|
|
|
|
|
|
|
|
# Origin
|
|
|
|
|
|
|
|
|
|
This code is maintained on GitHub at the following link:
|
|
|
|
|
|
|
|
|
|
https://github.com/google/gps-measurement-tools
|
|
|
|
|
|
|
|
|
|
# Initial setup:
|
|
|
|
|
|
|
|
|
|
1. Extract the contents of the zip file to a directory
|
|
|
|
|
2. Open and run ProcessGnssMeasScript.m, when prompted by Matlab select `Change dir`
|
|
|
|
|
|
|
|
|
|
## To process a log file you collected from GnssLogger:
|
|
|
|
|
|
|
|
|
|
1. save the log file in a *./demoFiles* directory
|
|
|
|
|
2. edit ProcessGpsMeasScript.m, change `prFileName` to log filename
|
|
|
|
|
3. run ProcessGpsMeasScript.m
|
|
|
|
|
|
|
|
|
|
The code includes a function (GetNasaHourlyEphemeris.m) to read ephemeris
|
|
|
|
|
files from the NASA's archive of Space Geodesy Data, ftp://cddis.gsfc.nasa.gov
|
|
|
|
|
It will automatically go to the ftp when you have a new log file.
|
|
|
|
|
On some systems you need to use passive mode FTP; if this is required, see
|
|
|
|
|
The Mathworks site for how to do it.
|
|
|
|
|
Or (simpler): get the appropriate ephemeris file 'by hand' from the Nasa ftp
|
|
|
|
|
site (GetNasaHourlyEphemeris.m will tell you the correct url and filename),
|
|
|
|
|
copy the file to the directory where your log file is,
|
|
|
|
|
and GetNasaHourlyEphemeris.m will read it from there.
|
|
|
|
|
|
|
|
|
|
## For a summary of the open source GNSS Measurements Tools
|
|
|
|
|
|
|
|
|
|
See ~/gpstools/opensource/Contents.m or type 'help opensource' in matlab
|
|
|
|
|
command window.
|
|
|
|
|
|
|
|
|
|
# Platform specific notes:
|
|
|
|
|
|
|
|
|
|
For Windows: use '\' (backslash), instead of '/' for directories.
|
|
|
|
|
|
|
|
|
|
For Mac: when installing MATLAB.
|
|
|
|
|
System Preferences --> Security & Privacy -->
|
|
|
|
|
Allow Apps to be downloaded from: Mac App Store and identified developers
|
|
|
|
|
|
|
|
|
|
Uncompress/Unzip utility called from GetNasaHourlyEphemeris.m:
|
|
|
|
|
The ephemeris on the Nasa ftp is Unix-compressed. GetNasaHourlyEphemeris will
|
|
|
|
|
automatically uncompress it, if you have the right uncompress function on your
|
|
|
|
|
computer. If you need to install an unzip utility, see http://www.gpzip.org
|
|
|
|
|
Then search for 'uncompress' in the GetNasaHourlyEphemeris function to find and
|
|
|
|
|
edit the name of the unzip utility:
|
|
|
|
|
|
|
|
|
|
unzipCommand='uncompress';%edit if your platform uses something different
|
|
|
|
|
|
|
|
|
|
If you uncompress the file 'by hand' and rerun GetNasaHourlyEphemeris.m, it will
|
|
|
|
|
read the uncompressed file.
|
|
|
|
|
|
|
|
|
|
# Copyright Notice
|
|
|
|
|
|
|
|
|
|
Copyright 2016 Google Inc.
|
|
|
|
|
|
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
|
|
|
you may not use this file except in compliance with the License.
|
|
|
|
|
You may obtain a copy of the License at
|
|
|
|
|
|
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
|
|
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
|
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
|
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
|
|
|
See the License for the specific language governing permissions and
|
|
|
|
|
limitations under the License.
|
