  In this paper, we introduce AERIQ: a software-defined radio (SDR) based I/Q
measurement and analysis framework for wireless signals for aerial
experimentation. AERIQ is integrated into controllable aerial vehicles, it is
flexible, repeatable, and provides raw I/Q samples for post-processing the data
to extract various key parameters of interest (KPIs) over a 3D volume. Using
SDRs, we collect I/Q data with unmanned aerial vehicles (UAVs) flying at
various altitudes in a radio dynamic zone (RDZ) like outdoor environment, from
a 4G LTE eNB that we configure to operate at 3.51 GHz. Using the raw I/Q
samples, and using Matlab's LTE Toolbox, we provide a step-by-step description
for frequency offset estimation/correction, synchronization, cell search,
channel estimation, and reference signal received power (RSRP). We provide
various representative results for each step, such as RSRP measurements and
corresponding analytical approximation at different UAV altitudes, coherence
bandwidth and coherence time of the channel at different UAV altitudes and link
distances, and kriging based 3D RSRP interpolation. The collected raw data as
well as the software developed for obtaining and post-processing such data are
provided publicly for potential use by other researchers. AERIQ is also
available in emulation and testbed environments for external researchers to
access and use as part of the NSF AERPAW platform at NC State University.
