  In this study, we measure the response of matter and halo projected power
spectra $P^{\rm 2D}_{\rm XY}(k)$ (X, Y are matter and/or halos), to a
large-scale density contrast, $\delta_{\rm b}$, using separate universe
simulations. We show that the fractional response functions, i.e.,
$\mathrm{d}\ln P^{\rm 2D}_{\rm XY}(k)/\mathrm{d}\delta_{\rm b}$, are identical
to their respective three-dimensional power spectra within simulation
measurement errors. Then, using various $N$-body simulation combinations
(small-box simulations with periodic boundary conditions and sub-volumes of
large-box simulations) to construct {mock observations of projected fields}, we
study how super-survey modes, in both parallel and perpendicular directions to
the projection direction, affect the covariance matrix of $P^{\rm 2D}_{\rm
XY}(k)$, known as super-sample covariance (SSC). Our results indicate that the
SSC term provides dominant contributions to the covariances of matter-matter
and matter-halo spectra at small scales but does not provide significant
contributions in the halo-halo spectrum. We observe that the large-scale
density contrast in each redshift shell causes most of the SSC effect, and we
did not observe a SSC signature arising from large-scale tidal field within the
levels of measurement accuracy. We also develop a response approach to
calibrate the SSC term for cosmic shear correlation function and galaxy--galaxy
weak lensing, and validate the method by comparison with the light-cone
ray-tracing simulations. Our method provides a reasonably accurate, albeit
computationally inexpensive, way to calibrate the covariance matrix for
clustering observables available from wide-area galaxy surveys.
