  We report a new version of spectral phase interferometry for direct electric
field reconstruction (SPIDER), which enables consistency checking through the
simultaneous acquisition of multiple shears and offers a simple and precise
calibration method. By mixing the test pulse with two spatially chirped ancilla
fields we generate a single-shot interferogram which contains multiple shears,
the spectral amplitude of the test pulse, and the reference phase, which is
accurate for broadband pulses. All calibration parameters - shear,
upconversion-frequency and reference phase position - can be accurately
obtained from a single calibration trace.
