Class vp
for a vertical profile of animals
# S3 method for vp summary(object, ...) is.vp(x) # S3 method for vp dim(x)
object | An object of class |
---|---|
... | Additional arguments affecting the summary produced. |
x | An object of class |
For is.vp
: TRUE
if its argument is of class vp
.
For dim.vp
: dimensions of the profile data.
An object of class vp
contains a vertical profile. A vertical profile
contains a collection of quantities, with each quantity having values at
different altitude layers above the earth's surface, typically equally
spaced altitudinal layers.
Data contained in this class object should be accessed with the
get_quantity function. Information stored under attributes
(see below) can be accessed directly.
A vp
object is a list containing
radar
the radar identifier
datetime
the nominal time of the profile
data
the profile data, a list containing:
height
height above mean sea level (m). Alt. bin from height to height+interval)
u
speed component west to east (m/s)
v
speed component north to south (m/s)
w
vertical speed (unreliable!) (m/s)
ff
horizontal speed (m/s)
dd
direction (degrees, clockwise from north)
sd_vvp
VVP radial velocity standard deviation (m/s)
gap
Angular data gap detected (T/F)
dbz
Animal reflectivity factor (dBZ)
eta
Animal reflectivity (cm^2/km^3)
dens
Animal density (animals/km^3)
DBZH
Total reflectivity factor (bio+meteo scattering) (dBZ)
n
number of points VVPvelocity analysis (u,v,w,ff,dd)
n_all
number of points VVP st.dev. estimate (sd_vvp)
n_dbz
number of points density estimate (dbz,eta,dens)
n_dbz_all
number of points total reflectivity estimate (DBZH)
attributes
list with the profile's \what
,
\where
and \how
attributes
NA
Maps to 'nodata' in the ODIM convention: value to denote areas void of data
(never radiated)
NaN
Maps to 'undetect' in the ODIM convention: denote areas below the measurement
detection threshold (radiated but nothing detected). The value is also used when there are too
few datapoints to calculate a quantity.
0
Maps to 0 in the ODIM convention: denote areas where the quantity has a measured
value of zero (radiated and value zero detected or inferred).
It depends on a radar's detection threshold or signal to noise ratio whether it safe to assume an 'undetect' is equivalent to zero. When dealing with close range data only (within 35 km), it is typically safe to assume aerial densities (dens) and reflectivities (eta) are in fact zero in case of undetects.
#> Vertical profile (class vp) #> #> radar: seang #> source: WMO:02606,RAD:SE50,PLC:Angelholm,NOD:seang,ORG:82,CTY:643,CMT:Swedish radar #> nominal time: 2015-10-18 18:00:00 #> generated by: vol2bird 0.3.17# check that the object is a vp object: is.vp(example_vp)#> [1] TRUE#> [1] 25 16