Can these tests be done from ground level at Inverter/DC Isolators?
I/V Curve measurement is used to check correct operation of the PV panels. The connection for I/V curve test requires users to connect the PV voltage probe and current clamp to the DC inverter switch input, hence these tests can be done from ground level where the Inverter is located.
On the other hand, for calculation of STC results, Irradiance and temperature (ambient or cell) values must be measured or be entered manually before the I/V test on the inverter side. You can use the PV remote unit to measure this on the roof.