|| AAAS || [[http://en.wikipedia.org/wiki/American_Association_for_the_Advancement_of_Science|Amercian Association for the Advancement of Science]] ||
|| ACIGA || [[http://www.anu.edu.au/Physics/ACIGA/|Australian Consortium for Interferometric Gravitational Astronomy]] ||
|| ACWP || Actual Cost of Work Performed ||
|| ADC || [[http://en.wikipedia.org/wiki/Analog-to-digital_converter|Analog-to-Digital Converter]] ||
|| AdL || Advanced LIGO ||
|| ALS || Arm Length Stabilization ||
|| AMU || [[http://en.wikipedia.org/wiki/Atomic_mass_unit|Atomic Mass Unit]] || See also RGA ||
|| ANU || Australian National University ||
|| AOC || Adaptive Optics Compensation ||
|| AOM || [[http://en.wikipedia.org/wiki/Acousto-optic_modulator|Acousto-Optic Modulator]] ||
|| AOS || Auxiliary Optics System ||
|| API || Application Programming Interface ||
|| ARMA || Autoregressive Moving Average ||
|| ASC || Alignment Sensing and Control ||
|| [[ASS]] || Alignment Sensing and Stabilization ||
|| ATM || Asynchronous Transfer Mode (communications protocol) ||
|| BAC || Budget at Completion ||
|| BCWP || Budgeted Cost of Work Performed ||
|| BCWS || Budgeted Cost of Work Scheduled ||
|| BH || Black Hole ||
|| BSC || Beam Splitter Chamber also Basic Symmetric Chamber ||
|| CACR || Center for Advanced Computer Research (Caltech) ||
|| CAD || Computer Aided Design ||
|| CB&I || Chicago Bridge & Iron ||
|| CCB || Change Control Board ||
|| CCD || Charged Coupled Device ||
|| CDR || Conceptual Design Review ||
|| CDRL || Contract Data Requirements List ||
|| CDS || Control and Data Systems ||
|| COC || Core Optics Components ||
|| CSIRO || Commonwealth Scientific and Industrial Research Organization (Australia) ||
|| CSSR || Cost Schedule Status Report ||
|| CW || Continuous Wave ||
|| DAC || [[http://en.wikipedia.org/wiki/Digital-to-analog_converter|Digital-to-Analog Converter]] ||
|| DAQ || Data Acquisition System ||
|| DCC || [[http://antares.ligo.caltech.edu/dcc/|Document Control Center]] ||
|| DFG || Dynamic gravity Field Generator ||
|| DMRO || Differential Mode Read-Out ||
|| DRR || Design Requirements Review ||
|| DSP || Digital Signal Processing ||
|| [[http://www.ligo.caltech.edu/~e2e/|E2E]] || End-To-End Modeling (interferometer simulation software package) ||
|| EAC || Estimate at Completion ||
|| ECD || Eddy Current Damping ||
|| EPI || External Pre-Isolator ||
|| EPICS || [[http://en.wikipedia.org/wiki/EPICS|Experimental Physics and Industrial Control System]] ||
|| ER || Engineering Run ||
|| ETF || Engineering Test Facility ||
|| ETM || End Test Mass ||
|| Ex || Engineering Run x (e.g. E4 is Engineering Run 4) ||
|| FAC || Facility Modifications ||
|| FDR || Final Design Review ||
|| FFT || Fast (Discrete) Fourier Transform ||
|| FIR || Finite Impulse Response ||
|| FSS || Frequency Stabilization Servo ||
|| FTE || Full Time Equivalent ||
|| GASF || Geometrical Anti-Spring Filter ||
|| GEO || British-German Cooperation for Gravity Wave Experiment ||
|| GFLOPS || Billion (Giga) Floating Point Operations Per Second ||
|| GG || Gravity Gradients ||
|| GPS || Global Positioning System ||
|| GRB || [[http://en.wikipedia.org/wiki/Gamma_ray_burst|Gamma-Ray Burst]] ||
|| GUI || Graphical User Interface ||
|| GWDAW || Gravitational Wave Data Analysis Workshop ||
|| GWIC || Gravitational Wave International Committee ||
|| HAM || Horizontal Access Modules --type of vacuum chamber || See also BSC ||
|| HEPI || Hydraulic External Pre-Isolator ||
|| HPSS || High Performance Storage System (IBM) ||
|| HVAC || Heating, Ventilation and Air Conditioning ||
|| IDE || Integrated Drive Electronics (disk standard) ||
|| IFO || Interferometer ||
|| i.i.d. || Independent and identically-distributed ||
|| IIR || Infinite Impulse Response ||
|| !InGaAs || Indium-Gallium-Arsenide ||
|| INSA || French National Institute for Applied Science ||
|| IO || Input Optics ||
|| IP || Inverted Pendulum ||
|| ISC || Interferometer Sensing and Control ||
|| [[http://lhocds.ligo-wa.caltech.edu:8000/40m/Intensity_Stabilization_Servo|ISS]] || Intensity Stabilization Servo ||
|| ITM || Input Test Mass ||
|| IV&V || Integration, Verification, and Validation ||
|| kpc || Kiloparsec ||
|| LAL || LIGO Algorithm Library ||
|| LASTI || LIGO Advanced System Test Interferometer ||
|| [[http://www.ldas-sw.ligo.caltech.edu/cgi-bin/index.cgi|LDAS]] || LIGO Data Analysis System ||
|| LHO || LIGO Hanford Observatory ||
|| LIGO || Laser Interferometer Gravitational-Wave Observatory ||
|| LISA || Laser Interferometer Space Antenna ||
|| LLO || LIGO Livingston Observatory ||
|| LMS || Least Mean Squares ||
|| LMXB || [[http://en.wikipedia.org/wiki/LMXB|Low-Mass X-Ray Binary]] ||
|| LSC || LIGO Scientific Collaboration ||
|| [[LSC]] || Length Sensing and Control System ||
|| LVDT || Linear Variable Differential Transducer ||
|| LVEA || Laser and Vacuum Equipment Area (at observatory corner station) ||
|| LZH || Laser Zentrum Hannover ||
|| MB || Megabyte ||
|| MC || [[Mode_Cleaner]] ||
|| MDC || Mock Data Challenge ||
|| MEDM || Motif Editor and Display Manager ||
|| MEPI || Magnetic External Pre-Isolator ||
|| MFLOPS || Million Floating Point Operations Per Second ||
|| MGASF || Monolithic Geometrical Anti-Spring Filter ||
|| MIMO || Multiple Input, Multiple Output ||
|| MOPA || Master Oscillator-Power Amplifier ||
|| MOU || Memorandum of Understanding ||
|| Mpc || Megaparsec ||
|| MPI || Message Passing Interface ||
|| MRE || Major Research Equipment ||
|| MSU || Moscow State University ||
|| NBI || Neutron Star Binary Inspiral ||
|| NDS || Network Data Server ||
|| NPRO || Non-Planar Ring Oscillator ||
|| NS || Neutron Star ||
|| OAF || Online Adaptive Filtering ||
|| OMC || Output Mode Cleaner ||
|| OOP || Object-Oriented Programming ||
|| OPD || Optical Path Difference ||
|| OSA || Optical Spectrum Analyser ||
|| OSB || Operations Support Building ||
|| OSEM || Optical Shadow Sensor and Magnetic Actuator ||
|| PAC || Program Advisory Committee ||
|| PDR || Preliminary Design Review ||
|| PDRR || Preliminary Design Requirements Review ||
|| PDT || Photodetector ||
|| PEM || Physical and Environmental Monitor ||
|| PM || Project Management ||
|| PMC || Pre Mode Cleaner ||
|| PMP || Project Management Plan ||
|| Ppm || Parts per million ||
|| PRC || Power Recycling Cavity ||
|| PRM || Power Recycling Mirror ||
|| PSL || Prestabilized Laser ||
|| PZT || !PbZr,,x,,Ti,,1-x,,O,,3,, (lead zirconate titanate, a piezoelectric material) ||
|| QND || Quantum Non-Demolition ||
|| QPD || Quadrant Photo Diode ||
|| R&D || Research and Development ||
|| RAID || Redundant Array of Inexpensive Disks ||
|| RC || Recycling Cavity ||
|| REO || Research Electro-Optics (Company Name) ||
|| REU || Research Experience for Undergraduates ||
|| RF || Radio Frequency ||
|| RFP || Request for Proposal ||
|| [[RGA]] || [[http://en.wikipedia.org/wiki/Residual_gas_analyzer|Residual Gas Analyzer]] ||
|| RLS || Recursive Least Squares ||
|| RMS || Root mean square ||
|| RSE || Resonant Sideband Extraction ||
|| s || Second ||
|| s/s || Samples/second ||
|| SAP || Sapphire Core Optics ||
|| SAS || Seismic Attenuation System ||
|| SEI || Seismic Isolation System ||
|| SEM || Secondary Emission Monitor ||
|| SIOM || Shanghai Institute of Optical Materials ||
|| SISO || Single Input, Single Output ||
|| SLC || Stray Light Control ||
|| [[SOS]] || Small Optics Suspension ||
|| SPICE || Simulation Program with Integrated Circuit Emphasis ||
|| SR || Signal Recycled (interferometer configuration) ||
|| SRD || Science Requirements Document ||
|| SRM || Signal Recycling Mirror ||
|| SUP || Support Equipment ||
|| SURF || [[http://www.surf.caltech.edu/|Summer Undergraduate Research Fellowship]] || See also [[40m Summer Projects]] ||
|| [[SUS]] || Suspension System ||
|| TAMA || Japanese Interferometric Gravitational-Wave Project ||
|| TB || TeraByte ||
|| TCS || Thermal Compensation System ||
|| TLA || Three Letter Acronym ||
|| TNI || Thermal Noise Interferometer ||
|| UGF || Unity Gain Frequency ||
|| UHV || Ultra High Vacuum ||
|| UL || Upper Limits  ||
|| VCO || Voltage Controlled Oscillator ||
|| VEA || Vacuum Equipment Area (at observatory mid- and end-stations) ||
|| [[http://en.wikipedia.org/wiki/Virgo_interferometer|VIRGO]] || Italian-French Laser Interferometer Collaboration ||
|| [[http://en.wikipedia.org/wiki/VMEbus|VME]] || Versa Modular Eurocard (IEEE 1014) ||
|| VSRM || Variable Signal Recycling Mirror ||
|| WAN || Wide Area Network ||
|| WBS || Work Breakdown Structure ||
|| WFS || Wave-Front Sensor ||