Hi Jim,
The weather stations cannot be upgraded. The Horus Kestrel Weather Tracker is embedded with ATrag, and is too complex to upgrade. You would have to get a whole new unit. Kestrel does have a Customer Care Discount program where you may trade in your current Kestrel for credit towards the new Kestrel Weather Tracker with Horus Vision. The Kestrel you turn in will then be donated to AmericanSnipers.org.
To learn more about the Customer Care Discount program, please contact Kestrel toll free at (800) 784-4221 or (610) 447-1555.
LIz
