parameterErrorEstimates: Incoherent scatter plasma parameter fit error estimates

In ilkkavir/ISgeometry: ISgeometry

Incoherent scatter plasma parameter fit error estimates

Description

Standard deviations of fitted plasma parameters when measured with the given radar system.

Usage

parameterErrorEstimates(
        lat,
        lon,
        alt,
         Ne,
         Ti,
         Te,
       Coll,
       Comp,
  fwhmRange,
       resR,
    intTime,
        pm0 = c(30.5,16),
      hTeTi = 110,
     Tnoise = 300,
         Pt = 3.5e6,
   locTrans = SKI,
     locRec = list(SKI,KAR,KAI),
  fwhmTrans = 2.1,
    fwhmRec = c(1.2,1.7,1.7),
     RXduty = c(.75,1,1),
mineleTrans = 30,
  mineleRec = 30,
     fradar = 233e6,
 phArrTrans = TRUE,
   phArrRec = TRUE,
fwhmIonSlab = 50,
  dutyCycle = .25)

Arguments

lat	Geocentric latitude of the measurement volume [deg north]
lon	Geocentric longitude of the measurement volume [deg east]
alt	Altitude of the measurement volume [km]
Ne	Electron density [m^-3]
Ti	Ion temperature [K]
Te	Electron temperature [K]
Coll	Ion-neutral collision frequency [Hz]
Comp	Ion composition (fraction of ion with mass pm0[2] out of the total ion number density)
fwhmRange	Range resolution in ACF decoding [km]
resR	Range resolution in the plasma parameter fit [km]
intTime	Integration time [s], default 10
pm0	Ion masses [amu], default c(30.5,16)
hTeTi	Altitude, below which Te=Ti is assumed, [km], default 110
Tnoise	Receiver noise temperature [K], default 300
Pt	Transmitter power(s) [W], default 3.5e6
locTrans	Transmitter location(s), list of lat, lon, [height] in degress [km], default list(c(69.34,20.21))
locRec	Receiver locations, list of lat, lon, [height] in degrees [km], default list(c(69.34,20.21),c(68.48,22.52),c(68.27,19.45))
fwhmTrans	Transmitter beam width(s) (at zenithg for phased-arrasy), [full width at half maximu, degrees], default c(2.1)
fwhmRec	Receiver beam widhts (at zenith for phased-arrays) [full width at half maximum, degrees], default c(1.2,1.7,1.7)
RXduty	"Receiver duty cycle" for each receiver, default c(.75,1,1)
mineleTrans	Elevation limit of the transmitter [deg], default c(30)
mineleRec	Elevation limit of the receivers [deg], default c(30,30,30)
fradar	Radar system carrier frequency [Hz], default 233e6
phArrTrans	Logical is (are) the transmitter(s) phased array(s)? Default c(T)
phArrRec	Logical, are the receivers phased-arrays? A vector with a value for each receiver. Default c(T,T,T)
fwhmIonSlab	Thickness of the ion slab that causes self-noise [km], default 100
dutyCycle	Transmitter duty cycle, default 0.25

Value

errtabs A list of error vectors

errtabs$los is a list of error vectors for each individual site. In the same order in which the receivers are listed in locRec, fwhmRec, etc. In each vector, the elements are in the order dNe, dTi, dT, dColl, dVi, dp

errtabs$multistatic is an error vector for "multistatic" analysis that merges data from all receivers. The velocity error estimate is the square root of the trace of the error covariance matrix of three orthogonal velocity vector components, and thus gives an upper limit that the standard deviation of any projection of the velocity vector cannot exceed. If errors of all vector components are equal, the true error is sqrt(3) times the given error.

Author(s)

Ilkka Virtanen (University of Oulu, Finland) [e-mail]

References

1. Matti Vallinkoski, Statistics of incoherent scatter multiparameter fits, Journal of Atmospheric and Terrestrial Physics, 50 (9), 839-851, 1988, https://doi.org/10.1016/0021-9169(88)90106-7

2. Markku Lehtinen, Ilkka I. Virtanen, and Mikko R. Orispää, EISCAT_3D Measurement Methods Handbook, 2014, http://urn.fi/urn:isbn:9789526205854

Examples

## Errors of Ne, Ti, Te, and Vi at 300 km altitude above Skibotn, when
Ne=1e11 m^-3, Ti=2000 K, Te=3000 K, ion-neutral collision frequency is
negligibly small, only O+ ions, 5 km modulation bit length,
post-integration to 20 km resolution and 60 s integration time.
 
parameterErrorEstimates(lat=SKI[1],lon=SKI[2],alt=300,Ne=1e11,Ti=2000,Te=3000,Coll=0,Comp=1,fwhmRange=5,resR=20,intTime=60)

ilkkavir/ISgeometry documentation built on Jan. 19, 2025, 5:26 p.m.