IQCapture#

class IQCapture( samples: ndarray, sample_period_ns: float, channels: tuple[str, ...], center_freq_hz: tuple[float, ...], t0_ns: int | None = None, dropped_samples: int = 0, )[source]#

Bases: object

One time-aligned block of IQ samples across one or more channels of a signal path.

Every row shares one timebase, so a multi-channel capture is aligned by construction.

Variables:

samples (numpy.ndarray) – Complex IQ samples shaped (n_channels, n_samples). Always two-dimensional, even for a single channel.
sample_period_ns (float) – Time between samples, in nanoseconds, shared by every row.
channels (tuple[str, ...]) – Channel each row of samples came from.
center_freq_hz (tuple[float, ...]) – Frequency each channel was tuned to, in Hz.
t0_ns (int | None) – Hardware timestamp of the first sample, in nanoseconds since the Unix epoch. None when the device has no clock of its own, in which case InstroSDR anchors the block to the host clock.
dropped_samples (int) – Samples lost before this block because the stream could not keep up.

Raises:

ValueError – If samples is not two-dimensional, or its row count does not match channels and center_freq_hz.

Example

capture = IQCapture(
    samples=np.zeros((1, 4096), dtype=np.complex128),
    sample_period_ns=1e9 / 2.4e6,
    channels=("0",),
    center_freq_hz=(100e6,),
)
row = capture.samples_for("0")

samples: ndarray#

sample_period_ns: float#

channels: tuple[str, ...]#

center_freq_hz: tuple[float, ...]#

t0_ns: int | None = None#

dropped_samples: int = 0#

property overflow: bool#

Whether any samples were dropped before this block.

Returns:: bool – True when dropped_samples is greater than zero.

samples_for(channel: str) → ndarray[source]#

Return the row of samples belonging to one channel.

Parameters:: channel (str) – Channel to read.
Returns:: numpy.ndarray – The channel’s complex IQ samples, one-dimensional.
Raises:: ValueError – If the capture holds no such channel.

center_freq_for(channel: str) → float[source]#

Return the frequency a channel was tuned to when these samples were taken.

Parameters:: channel (str) – Channel to read.
Returns:: float – Center frequency in Hz.
Raises:: ValueError – If the capture holds no such channel.

select( channels: Sequence[str], ) → IQCapture[source]#

Narrow this capture to a subset of its channels, keeping the shared timebase.

Parameters:: channels (Sequence[str]) – Channels to keep, in the order the rows should appear.
Returns:: IQCapture – A capture holding only channels, or this capture unchanged if they already match.
Raises:: ValueError – If any of channels is not in the capture.