| Acronym | Meaning |
| PPP | Parallelizing PreProcessor |
| PPS | Public Products Service |
| PPS | Physical Plant Services |
| PPS | Pulses Per Second |
| PPS-PODS | Precise Position System- Precise Orbit Determination System |
| PPTV | Parts Per Trillion (by Volume) |
| PPU | Peripheral Processor Unit |
| PRAIRE | Polarization Radar Illinois Rainfall Experiments |
| PRAIRE | Polarization Radar Illinois Rainfall Experiments |
| PRC | People's Republic Of China |
| PRC | People's Republic Of China |
| PRC | Inc. |
| PRCM | Paleoclimate Reconstructions Of Climate Modeling Observatory |
| PRE-AWIPS | Preprototype AWIPS |
| PRE-STORM | Preliminary Regional Experiment-STORM |
| PRE-STORM | Preliminary Regional Experiment-STORM |
| PRECIP | Processing Of Emissions By Clouds And Precipitation |
| PRECIP | Processing Of Emissions By Clouds And Precipitation |
| PRECP | Program On Nonlinearity Of Acid Precipitation Process |
| PRECP | Program On Nonlinearity Of Acid Precipitation Process |
| PRECP | Processing Of Emissions By Clouds And Precipitation |
| PRF | Pulse Repetition Frequency |
| PRIMO | Problems Related To Ionospheric Modeling And Observations Project |
| PRMS | Precipitation Runoff Modeling System |
| PROBE | Portable Remote Observations Of The Environment |
| PROFS | Program For Regional Observing And Forecasting Services |
| PROM | Programmable Read-Only Memory |
| PROPHET | Program For Research On Oxidants |
| PRT | Pulse Repetition Time |
| PRT | Platinum Resistance Thermometer |
| PRUDENCE | Prediction Of Regional Scenerios And Uncertainties For Defining European Climate Change Risks And Effects |
| PSA | Pressure Switch Assembly |
| PSA | Problem Statement Analyzer |
| PSA | Public Service Announcement (radio/TV Term) |
| PSAC | President's Science Advisory Committee |
| PSC | Geomagnetic Pulsation |
| PSC | Polar Stratospheric Cloud |
| PSC | Pittsburgh Supercomputing Center |
| PSCN | Program Support Computer Network |
| PSCNET | Pittsburgh Supercomputing Center Network |
| PSE | Polar Sunrise Experiment |
| PSI | Pounds Per Square Inch |
| PSI | Plan Shear Indicator |
| PSIA | Pounds Per Square Inch Absolute |
| PSID | Pounds Per Square Inch Differential |
| PSIG | Pounds Per Square Inch Gage |
| PSN | Piano Spaziale Nazionale |
| PSOS | Profiler Surface Observing System |
| PSPT | Precision Solar Photometric Telescope |
| PSU | Pennsylvania State University |