Link Information Variants | Data Provider Elements
Link Information
Link information provides the link budget for the CommSystem including interference parameters.Data Provider Variant: CommSystem
Available for these objects: CommSystem
Type: Time-varying data. Intended to be used only with elements from this same data provider.
Availability: Reports | Graphs | Dynamic Displays | Strip Charts
Pre-data required: "<TruncObjectPath>" - e.g. "Satellite/Sat1/Receiver/Receiver1"
Data Provider Elements
| Name | Dimension | Type | Description |
|---|---|---|---|
| Time | Date | Real Number or Text | Time. |
| Xmtr Name | Unitless | Text | Name of the Transmitter used in the link. |
| Rcvr Name | Unitless | Text | Name of the Receiver used in the link. |
| Link To ID | Unitless | Integer | Refers to the ID of the transmitter in the link analysis. |
| Multibeam Antenna Beam-ID | Unitless | Text | Refers to the ID of the beam within the Multibeam Transmitter used in the link analysis. |
| Xmtr Power | Power | Real Number | The RF power output of the transmitter as measured at the input to the antenna. This is a user selectable value. |
| Xmtr Gain | Ratio | Real Number | The antenna gain of the transmitter which is dependent on the antenna type selected. For transmitter models that do not have an antenna model, this is a user defined value. For the simple source transmitter, 0 dB is reported since the simple source transmitter is modeled as an isotropic radiator. |
| EIRP | Power | Real Number | The effective isotropic radiated power in the link direction. This value is the product of the transmitter power and the transmitter gain in the link direction with the inclusion of user defined post transmit gains and losses. |
| Xmtr Azimuth - Phi | Angle | Real Number or Text | The transmitter azimuth (Phi) is the angle between the transmitter body +x axis and the x-y projection of the link vector. |
| Xmtr Elevation - Theta | Angle | Real Number or Text | The transmitter elevation (Theta) is the angle between the transmitter antenna bore-sight vector and the link vector. |
| Rcvr Azimuth - Phi | Angle | Real Number or Text | The receiver azimuth (Phi) is the angle between the receiver body +x axis and the x-y projection of the link vector. |
| Rcvr Elevation - Theta | Angle | Real Number or Text | The receiver elevation (Theta) is the angle between the receiver antenna bore-sight vector and the link vector. |
| Multibeam Rcvr Antenna Beam-ID | Unitless | Text | Multibeam antenna beam ID refers to the ID of the beam within the multibeam receiver used in the link analysis. |
| Rcvd. Frequency | Frequency | Real Number | The received frequency is the frequency that the receiver is tuned to in order to communicate with the transmitter. This frequency may be auto-tracked or entered by the user in the receiver properties. |
| Freq. Doppler Shift | Frequency | Real Number | The frequency Doppler shift is the offset in frequency between the transmitted frequency and the received frequency. This value is zero for auto tracked receivers. |
| Rcvd. Iso. Power | Power | Real Number | Received isotropic power is the power at the receiver before the pre-receive gains/losses and the receiver antenna gain added (in dBW). It is equal to the EIRP with all the channel losses as well as the bandwidth overlap applied. |
| Carrier Power at Rcvr Input | Power | Real Number | Carrier Power at Rcvr Input is the power at the receiver after the receiver antenna gain added (in dBW). It is equal to the EIRP with all the channel losses as well as the bandwidth overlap and receiver gain applied. |
| Flux Density | PowerFluxDensity | Real Number | The power from the desired transmitter crossing a unit area normal to the direction of wave propagation. |
| Rcvr Gain | Ratio | Real Number | Receiver Gain is the antenna gain (in dBi) of the receiver which is dependent on the antenna type used. |
| Train | Temperature | Real Number | Train is the antenna noise temperature component attributed to the rain model. |
| Tatmos | Temperature | Real Number | Tatmos is the antenna noise temperature component attributed to the gaseous absorption model. |
| Tsun | Temperature | Real Number | Tsun is the antenna noise temperature component attributed to the sun. |
| Tearth | Temperature | Real Number | Tearth is the antenna noise temperature component attributed to the earth. This is applicable only to receivers not on the ground. |
| Tcosmic | Temperature | Real Number | Tcosmic is the antenna noise temperature component attributed to the cosmic background. This is applicable only to receivers not on the ground. |
| TuserCustomA | Temperature | Real Number | TuserCustomA is the antenna noise temperature component attributed to user defined custom loss model A. |
| TuserCustomB | Temperature | Real Number | TuserCustomB is the antenna noise temperature component attributed to user defined custom loss model B. |
| TuserCustomC | Temperature | Real Number | TuserCustomC is the antenna noise temperature component attributed to user defined custom loss model C. |
| Tother | Temperature | Real Number | Tother is the antenna noise temperature component attributed to other antenna noise sources. |
| Tantenna | Temperature | Real Number | Tantenna is the antenna noise temperature which is the sum of all the noise source components. |
| Tequiv | Temperature | Real Number | The equivalent system temperature is specified by the user as a constant value or computed at each time step from the receiver system temperature parameters defined by the user. |
| g/T | GainTempRatio | Real Number | G/T = (Receiver Gain)/(System Temperature at the Receiver). The ratio of the receive antenna gain G to the total system temperature T is the "figure of merit" for the receiver (in dB/K). The figure of merit is independent of the point where it is calculated. However, the gain and system temperature must be specified at the same point. |
| C/No | SpectralDensity | Real Number | The carrier to noise density ratio (C/No) where C is the carrier power and No = kT (Boltzmann's constant x system temperature) is the noise density. It is equivalent to C/N with a normalized Bandwidth (B=1). |
| C/(No+Io) | SpectralDensity | Real Number | The carrier to noise-plus-interference density ratio (C/(No+Io)), where C is the carrier power, No = kT (Boltzmann's constant * system temperature), and Io = interference power spectral density. |
| Bandwidth | Bandwidth | Real Number | Bandwidth is the Receiver Bandwidth. |
| Bandwidth Overlap | Ratio | Real Number | The bandwidth overlap factor is the fraction (between 0 and 1) of transmitted power which is contained within the receiver's bandwidth. The amount of power received by the receiver is equal to the transmitted EIRP multiplied by the bandwidth overlap factor and taking into account any propagation losses. |
| C/N | Ratio | Real Number | The carrier to noise ratio (C/N) where C is the carrier power and N = kTB (Boltzmann's constant x system temperature x bandwidth) is the noise power. |
| C/(N+I) | Ratio | Real Number | The carrier to noise-plus-interference ratio (C/(N+I)), where C is the carrier power, N = kTB (Boltzmann's constant * system temperature * bandwidth), and I = interference power. |
| Eb/No | Ratio | Real Number | The energy per bit to noise ratio (Eb/No) where Eb is the energy per bit and No = kT (Boltzmann's constant * system temperature). |
| Eb/(No+Io) | Ratio | Real Number | The energy per bit to noise-plus-interference ratio (Eb/(No+Io)), where Eb is the energy per bit, No = kT (Boltzmann's constant * system temperature), and Io = interference power spectral density. |
| BER | Unitless | Real Number | Bit Error Rate (BER) is the probability that a bit is in error (i.e. a zero is transmitted but a one is received). The BER is the number of bits in error divided by the total number of bits sent. STK uses table lookup from a .mod file to extract a BER given an Eb/No. STK interpolates the table as necessary to determine the appropriate bit error rate for a particular bit energy level. If the bit energy is smaller than the first value in the table, the bit error rate for the first value is used. If the bit energy is larger than the last value in the table, a default bit error rate of 1.0e-30 is used to indicate no errors. |
| BER+I | Unitless | Real Number | Bit error rate in the presence of interference (BER+I) is the probability that a bit is in error (i.e. a zero is transmitted but a one is received) in the interference environment. The BER+I is the number of bits in error divided by the total number of bits sent. STK uses table lookup from a .mod file to extract a BER+I given an Eb/(No+Io). STK interpolates the table as necessary to determine the appropriate bit error rate for a particular bit energy level. If the bit energy is smaller than the first value in the table, the bit error rate for the first value is used. If the bit energy is larger than the last value in the table, a default bit error rate of 1.0e-30 is used to indicate no errors. |
| C/I | Ratio | Real Number | In the Interference Information data provider, C/I is the carrier power from the desired signal over the individual interferer power. Note that the Link Information data provider defines C/I as the carrier power from the desired signal over the sum of all interferer powers. If only one interferer is part of the CommSystem, the two data providers will report the same value for C/I. |
| J/S | Ratio | Real Number | J/S is the jammer to signal ratio. |
| DeltaT/T | Ratio | Real Number | The ratio of interference power spectral density Io and receiver noise spectral density No. |
| Pwr Flux Density | PowerFluxDensity | Real Number | The interference power from an individual interference source, crossing a unit area normal to the direction of wave propagation and computed over a reference bandwidth of either 1 MHz, 40 kHz, 4 kHz, or 1 Hz. See "Power Flux Density Technical Notes". |
| Pol. Rel. Angle | Angle | Real Number or Text | The angle corresponding to the relative mismatch between the transmitted signal polarization and the receiver polarization. |
| Polarization Effic | Ratio | Real Number | The polarization match between the transmitted signal polarization and the receiving antenna (or in case of Simple and Medium models implied antenna) polarization. It is computed on a scale of 0 - - 1. The value of 1.0 represents the perfect match between the transmitter and the receiver polarizations. On the opposite end of the scale, the value of 0.0 represents a perfect mismatch. STK also provides an option to model Cross Polarization Leakage value. The polarization mismatch value can not drop below the user specified Cross Pol Leakage value. |
| Multibeam Xmtr Antenna Beam-ID | Unitless | Text | Unique ID for beam of a multibeam antenna. |
| Total Jammer Power At Rcvr Input | Power | Real Number | The total interference/jamming power entering the receiver due to all visible jammers. |
| Total RF Power | Power | Real Number | The total RF power entering the receiver due to the desired signal carrier and all the visible interferers/jammers. |
| Total Power At Rcvr Input | Power | Real Number | The total power received at the input of the receiver front end amplifier, which includes antenna gain, polarization mismatch, cable losses, etc. The total power is the sum of the desired signal power and all received interference signal power, in the direction of the interferer and within the receiver's bandwidth. |
| Rcvr Noise Power | Power | Real Number | The receiver's total internal noise power, which is computed from the receiver noise figure, antenna to receiver cable loss and the cable ambient temperature. |
| IoverN | Ratio | Real Number | The ratio of the total interference power as seen by the receiver across its entire bandwidth over the total receiver noise. |
| Range | Distance | Real Number | The range (i.e., distance between the primary and secondary object) at the given time. |
| UserCustomA Loss | Ratio | Real Number | Loss calculated by custom loss scripting plugin model A, written in VBscript or MATLAB. |
| UserCustomB Loss | Ratio | Real Number | Loss calculated by custom loss scripting plugin model B, written in VBscript or MATLAB. |
| UserCustomC Loss | Ratio | Real Number | Loss calculated by custom loss scripting plugin model C, written in VBscript or MATLAB. |
| Free Space Loss | Ratio | Real Number | Loss due to propagation through free space. |
| Atmos Loss | Ratio | Real Number | Loss calculated by the selected atmosphere model. |
| UrbanTerres Loss | Ratio | Real Number | Loss calculated by the selected Urban and Terrestrial model. |
| Rain Loss | Ratio | Real Number | Loss calculated by the selected rain model. |
| CloudsFog Loss | Ratio | Real Number | Loss calculated by the Clouds and Fog model. |
| TropoScintill Loss | Ratio | Real Number | Loss calculated by the troposphere Scintillation model. |
| Prop Loss | Ratio | Real Number | The total propagation loss computed across all enabled propagation models. |
| TcloudsFog | Temperature | Real Number | The noise temperature from the Cloud and Fog model. |
| TtropoScintill | Temperature | Real Number | The noise temperature from the Troposhperic Scintillation model. |
| Texternal | Temperature | Real Number | The noise temperature specified by the external noise temperature file. |
| TUrbanTerres | Temperature | Real Number | The noise temperature from the Urban and Terrestrial model. |
| Spectral Flux Density | PowerSpectralFluxDensity | Real Number | The power per unit area per unit bandwidth. The power is computed across the receiver's bandwidth as seen by the receiver's RF front end. The bandwidth is the receiver's total bandwidth. The dimension is Power / (Area * Bandwidth), and is typically represented in dBW/(m^2*Hz). |
| IonoFading Loss | Ratio | Real Number | Loss calculated by the Ionospheric Propagation Fading Loss Model. |
| TionoFading | Temperature | Real Number | The noise temperature from the Ionospheric Propagation Fading Loss Model. |