One of the most pressing needs in space weather forecasting is continuous, high-resolution monitoring of Earth's polar regions where magnetospheric energy has direct access to the upper atmosphere. Strong magnetic field perturbations signal enhanced energy deposition in the high latitudes. A National Science Foundation-sponsored initiative is allowing scientists access to magnetic perturbation data from the constellation of IRIDIUM satellites via the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) program led by Johns Hopkins University Applied Physics Laboratory. In this experiment, magnetometer data are extracted from 66 polar orbiting satellites, 11 in each of six orbit planes. Regular sampling cadence is 20 seconds. The polar orbits guarantee coverage of the auroral zones. In this presentation we describe first efforts to compare the AMPERE data at 780 km with Defense Meteorological Satellite Program spacecraft data acquired at higher altitude (850 km) and at higher resolution, but in fewer orbit planes. On a day with moderate geomagnetic activity, we find a general good agreement between the data sets. The combined data reveal clear asymmetries in current distributions in the northern and southern hemispheres. Further, there are instances of transient, but spatially extended surges. Some surges are localized in latitude, others cover broad swaths. We will discuss some our interpretations of the surges and the issues we face in merging these data sets for global mapping of the currents and fields that link Earth's upper atmosphere to geospace