AirspyAlign

class AirspyAlign : public kotekan::Stage

Kotekan stage to measure the time-lag between two real input streams.

Consumes raw short samples from two airspy producers. On REST request the stage captures lag_window samples from each input, then in the callback performs zero-padded FFT cross-correlation to estimate the integer sample lag between A and B. The lag, and optionally the full correlation magnitudes, are returned as JSON.

Buffers

• in_bufA Input kotekan buffer A.

  • Format: Array of short

  • Metadata: none

• in_bufB Input kotekan buffer B.

  • Format: Array of short

  • Metadata: none

REST endpoints

• GET <unique_name>/cal_lag — returns {"lag": int}

• GET <unique_name>/get_correlation — returns {"lag": int, “corr_pos”: […], “corr_neg”: […]}

Author

Keith Vanderlinde

Param lag_window:

UInt (default: input frame size in samples). Number of samples to capture.

Public Functions

AirspyAlign(kotekan::Config &config, const std::string &unique_name, kotekan::bufferContainer &buffer_container)

~AirspyAlign() override

virtual void main_thread() override

void cal_lag_callback(kotekan::connectionInstance &conn)

void get_correlation_callback(kotekan::connectionInstance &conn)