How to define reflectance of near infrared of solar radiation

radiance-general
1

Hi.I'm natchan.

Im investigating reflected light of sun from glazing of buildings with
radiance.

Radiance materials can be set reflectance of each RGB.

Then, can I define reflectance of near infrared(NIR, unvisible light) of
solar radiation?

Is the NIR reflectance equal to RGB reflectance?

I apologize for my poor English.

Thank you.