Dump1090 Altitude reporting above 60kft

How does Dump1090 deal with altitude above 60kft? I recently tracked a high altitude balloon with an ADS-B transponder. Once the balloon got above about 62kft the reported pressure altitude displayed as 1 meter but location was still correct. When the balloon descended below 62kft the reported altitude switched back to pressure altitude as expected.

Does Dump1090 assume an altitude above 60kft is bogus?

Depends on which dump1090 you’re talking about.

Historically, dump1090 wouldn’t accept these altitudes.
dump1090-mutability started accepting them here: github.com/mutability/dump1090/ … 8cc65b201c
piaware’s faup1090 includes this change, so piaware will feed the high altitudes, though the FA dump1090 webmap won’t display them as it’s using different code.

obj, thanks for the reply. That has to be the problem. I will switch over to the mutability version.