Analysis of Light Based Geolocator Data

Provides basic functions for global positioning based on light intensity measurements over time. Positioning process includes the determination of sun events, a discrimination of residency and movement periods, the calibration of period-specific data and, finally, the calculation of positions.


News

CHANGES IN GeoLight VERSION 2.00

Please view package vignette "GeoLight2.0" for detailed description on changes within functions and about additional functionalities.

CHANGES IN GeoLight VERSION 1.04

OVERVIEW

o roxygenized and ported to GitHub

CHANGES IN GeoLight VERSION 1.03

OVERVIEW

o We thank Eli Brigde, Michael Sumner and Eldar Rakhimberdiev for fruitful comments during a workshop. o Version 1.03 provides one new filter function and some additional graphical output o With the help of the users we could remove some bugs and improve the package significantly

NEW FUNCTIONS

o loessFilter
Filter to remove outliers based on residuals from a local
polynomial regression fitting process (loess). 

SIGNIFICANT USER-VISIBLE CHANGES

o   twilightCalc
A new argument was added to the twilightCalc function: preSelection.
If preSelection=TRUE a routine will go trough all times where the light
intensity crosses the light threshold. Only the earliest in the morning
and the latest in the evening will be set as "choosen" for further
graphical examination. This usually results in a much faster interactive
process especially if the light intensity fluctuates much around the 
light threshold.	


o   getElevation
In addition to the already existing graph where the user gets an
overview of all defined twilight times within the calibration period
as well as the deviation from the optimal sun elevation, another plot shows
the sun elevaion curves for the calibration period at the known position
and the defined twilight events. The two graphs are highly redundant but
we think that the new graph gives a better impression about the distribution
of the defined twilight events and whether single twilight events should
be excluded from the calibration period (i.e. twilight events which do not
represent the sunrise or sunset).

CHANGES IN GeoLight VERSION 1.02

OVERVIEW

o We thank all users providing helpful comments and helping to identify bugs o Some modifications to internal code.

NEW FUNCTIONS

o lightFilter
Filter to remove noise in light intensity measurements during the night

CHANGES IN GeoLight VERSION 1.01

OVERVIEW

o We thank Eli Brigde for helpful comments. o We thank Michael U. Kemp (Author from the RNCEP Package) to help us writing a code for exporting a trip into Google Earth o James Fox provided details to write a transformation script for geolocator data from Migrate Technology Ltd. o Some modifications to internal code.

NEW FUNCTIONS

o luxTrans
Files with the siuffix .lux are derived from geolocators provided by Migrate Technology Ltd. 
luxTrans() produces a table with datetime and light recordings in a format 
required by GeoLight.
   	
o trip2kml
This function creates a .kml file from light intensity measurements over time that can ve viewed as a trip in Google Earth

SIGNIFICANT USER-VISIBLE CHANGES

o   twilightCalc
Code to calculate the times were light recordings pass the light intensity threshold
were modified. Therewith wrong calculations from the first versions should not appear
anymore. The new code is also faster. Most important, the way how users can judge
the calculated twilight events has changed significantly. The function provides a
very similar plot (with some more details about the date and the time of the twilight events),
however wrong definitions can be deleted by clicking the first mouse buttom at the 
particular twiligth event (and vice verca). Clicking the second mouse bottom will move the
time series forwards (no backward moving is possible).

o   changeLight
The function got an additional argument: quantile! If this argument is specified e.g. 0.6, only
change points with higher probabilities than 60% of all calculated probabilites will be 
considered as changes in the movement behavior. The arguments rise.prob and set.prob will not be
considered if quantile is defined by a value.

Reference manual

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install.packages("GeoLight")

2.0.0 by Simeon Lisovski, 4 years ago


Browse source code at https://github.com/cran/GeoLight


Authors: Simeon Lisovski , Simon Wotherspoon , Michael Sumner , Silke Bauer , Tamara Emmenegger


Documentation:   PDF Manual  


Task views: Handling and Analyzing Spatio-Temporal Data


GPL (>= 2) license


Imports changepoint, fields, MASS

Depends on maps

Suggests knitr


Imported by FLightR.


See at CRAN