Progress in dual frequency ADS-B payload flight experiments on stratospheric balloons

Summary and Conclusions for TAMLACE Balloon Experiment: • 100K´+ float time was 2:43 (>95K´ for 3:06) • Payload received and transmitted both frequencies as before • Proof-of-principle for use in high message traffic areas at peak time saw significantly more aircraft than first time on both 1090 and 978 MHz links (987 different A/C on UAT TIS-B link) • FAA Seattle Center “saw” balloon with operational ATC equipment during both ascent and descent • Balloon/TAMLACE communicated with at least one of 23 GBTs in region > 98% — TIS-B ground uplinks — both links — at A/C max range of 550 nmi — UAT TIS-B messages for ownship TAMLACE 1090ES always transmitted from GBTs at < 42, 000 feet altitude (encoder limits for altimeter reading) • Number of Aircraft Detected: — UAT — 895 A/C detected overall • 9 A/C Direct, max range air-air ∼220 nmi • 887 via TIS-B from GBTs, max range uplink was ∼550 nmi — 1090ES — 759 A/C detected via 1090ES • 391 A/C Direct, max range air-air (350 nmi max range solid track) • Max detection range for 1090ES air-air was ∼500 nmi • 368 via TIS-B from GBTs (550 max range max) • Experiment Successful.