During the operational phase of the Polar mission, the PWI modes of operation will be altered several times per orbit to optimize the data return and to meet scientific objectives. The PWI instrument offers a great deal of flexibility in the selection of operational modes. In the survey mode of operation, each receiver will be set to a pre-defined default mode with an optimal sensor configuration to meet the scientific objectives of the mission. The features of the default modes, the antenna selection, and the receiver configuration are listed in Table 7.
Low-rate data from the instrument will be collected on the spacecraft tape recorder for later transmission to the ground during scheduled tape recorder dumps. Occasionally, the HFWR will be commanded in a special mode in which the waveform data are transmitted directly to the ground-tracking stations via the 256 kb/s wideband link. This high-rate waveform mode of the HFWR is only used for the real-time transmission of pre-selected waveform receiver data and will take the place of normal wideband data transmission.
Once the initial testing period has been completed, the WBR will operate on a 15% duty cycle, allowing 3.6 hours of real-time data transmission per day via the 256 kb/s data downlink. In the default mode, the 11 kHz filter and the baseband translation mode will be used to obtain high-resolution spectrums in various regions of the magnetosphere. In the WBR default mode, the 8-bit conversion mode will be used because it allows the maximum dynamic range and duty cycle for survey purposes.
