Pushing precision and accuracy of RR Lyrae variables as distance indicators

RR Lyrae variables are excellent distance indicators thanks to their visual magnitude-metallicity relation and well-defined Period-Luminosity Relations (PLRs) at infrared wavelengths. These population II variables together with the tip of the red giant branch provide primary calibration for the first-rung of the population II distance ladder. We will present new empirical calibration of RR Lyrae PLRs at near-infrared wavelengths using our data from the ongoing CFHT-WIRCam RR Lyrae program. We will discuss the systematic uncertainties involved in the calibration of these relations based on the latest Gaia EDR3 parallaxes and the implication for the cosmic distance scale.