height above touchdown 
Hash Anchor Table 
Highest astronomical tide 
humid-air turbine 
hypoxanthine-aminopterin-thymidine 
Air Taxi 
h after treatment 
haemagglutination test 
Haitian French Creole 
Halsted aphasia test 
handgrip-apexcardiographic test 
Hardware Acceptance Test 
Hardware Address Translation 
Hardware Address Translator 
harmonic attenuation table 
HARPOON Assistance Team 
Hashed Address Table 
HATTERAS INCOME SECURITIES, INC. 
Hawaii Assistive Technology 
head, arm, trunk 
headache of tension 
Health and Activity Tracking 
Health Attribution Test 
Heap Analysis Tool 
Hearing Assistive Technology 
Height Above Terrain 
Help Authoring Tool 
hemagglutination test 
heparin-associated thrombocytopenia 
heparin-assosiated thrombocytopenia