March 30, 2021

RRI Lv1 HDF File


CASSIOPE SPACECRAFT (Swarm-E)
PROCESSED DATA HANDBOOK

RRI Lv1 HDF File


An RRI level 1 HDF file is generated for each RRI turn-on session.

The RRI level 1 HDF files contains 3 objects: A CASSIOPE ephemeris object, an RRI Data object and an RRI Settings object. The attributes of each object are specified below.

CASSIOPE Ephemeris object attributes:

  • Altitude (km)
  • Ephemeris Mission Elapsed Time (seconds since May 24, 1968 00:00 UT)
  • J2000 GEI Position (km)
  • J2000 GEI Velocity (km/s)
  • ITRF GEO Position (km)
  • ITRF GEO Velocity (km/s)
  • GSM Position (km)
  • WGS-84 Geographic Latitude (°)
  • WGS-84 Geographic Longitude (°)
  • IGRF MLT (hr)
  • IGRF Magnetic Latitude (°)
  • IGRF Magnetic Longitude (°)
  • Spacecraft attitude pitch angle (°)
  • Spacecraft attitude roll angle (°)
  • Spacecraft attitude yaw angle (°)

RRI Data object attributes:

  • Channel A frequencies (Hz)
  • Channel B frequencies (Hz)
  • RRI Packet Numbers (ID of each time-tagged 4×29-sample packet sent out from RRI)
  • Radio Data Monopole 1 (mV)
  • Radio Data Monopole 2 (mV)
  • Radio Data Monopole 3 (mv)
  • Radio Data Monopole 4 (mv)
CASSIOPE RRI Monopoles

RRI Settings object attributes:

AttributeDescription
Antenna 1 GainMonopole 1 gain setting (Low, Medium, or High)
Antenna 2 GainMonopole 2 gain setting (Low, Medium, or High)
Antenna 3 GainMonopole 3 gain setting (Low, Medium, or High)
Antenna 4 GainMonopole 4 gain setting (Low, Medium, or High)
Antenna ConfigurationAntenna configuration, Monopole or Dipole
Bandwidth A (kHz)Bandwidth for Channel A, 5 kHz or 30 kHz
Bandwidth B (kHz)Bandwidth for Channel B, 5 kHz or 30 kHz
Data FormatLists the four data streams that are output by RRI. Possibilities are I1, Q1, I2, Q2, I3, Q3, I4, and Q4, where I represents the in-phase signal from a monopole, and Q represents the quadrature output from a monopole. For example, a Data Format of I1Q1I3Q3 in Monopole mode means in-phase and quadrature data are output from monopoles 1 and 3. In Dipole mode this represents I and Q from each dipole.
Delta Frequency A (Hz)For a linear sweep this is the step size in Hz of each frequency step. For a logarithmic sweep this is the starting step size, with each step size being twice the one before it. This has no meaning for fixed frequency. Applies to Channel A.
Delta Frequency B (Hz)For a linear sweep this is the step size in Hz of each frequency step. For a logarithmic sweep this is the starting step size, with each step size being twice the one before it. This has no meaning for fixed frequency. Applies to Channel B.
Dwell Time A (s)Number of seconds to dwell on each frequency of a sweep, Channel A
Dwell Time B (s)               Number of seconds to dwell on each frequency of a sweep, Channel B
End Frequency A (Hz)End frequency of a sweep, Channel A. Note that the sweep extends one step past the end of the range, i.e. the sweep returns to the start frequency when f > f_end.
End Frequency B (Hz)End frequency of a sweep, Channel B. Note that the sweep extends one step past the end of the range, i.e. the sweep returns to the start frequency when f > f_end.
Start Frequency A (Hz)Start Frequency for Channel A
Start Frequency B (Hz)Start Frequency for Channel B
Sweep Mode ASweep mode of Channel A. (Fixed Frequency, Linear Sweep, or Logarithmic Sweep)
Sweep Mode BSweep mode of Channel B. (Fixed Frequency, Linear Sweep, or Logarithmic Sweep)

RRI has a sampling frequency of 62500.33933 Hz.

Details of the bandwidth response, calibration, and instrument components can be found in James et al., The e-POP Radio Receiver Instrument on CASSIOPE, Space Science Reviews, 2015, Vol 189 (1), p 155-160.