Accuracy of Commercially-Available Speech Recognition Systems in Identifying PIREP Terminology

Pilot Reports (PIREPs) are an important source of information that aids, other pilots, air traffic control, and operational aviation meteorologists in terms of forecasting and updating weather advisories such as SIGMETs. Pilots rely upon PIREPs so they can avoid hazardous weather and fly their aircraft in the safest manner possible. However, many PIREPs are not successfully submitted or transmitted to the many end users which impedes their ability to be used to keep the NAS safe. The National Transportation Safety Board (NTSB) made several recommendations for increasing the effectiveness and distribution of PIREPs, including receiving PIREPs from pilots directly and automatically (NTSB, 2017). We recruited eighty-four native-speaking participants to read a short, average, and long PIREP scripts in order to test the performance of various speech recognition systems (SRSs). The spoken PIREPs were transcribed by SRSs and compared to the original PIREP scripts. The words that were deleted, substituted, and inserted were identified and used to calculate the word error rate (WER) and word information loss (WIL). The WERs and WILs were separately analyzed with a repeated-measures marginal model to compare the accuracy between each of the SRSs. Also, the interaction between each SRS and gender was analyzed. The results demonstrated that Google, LilySpeech, and Transcribe had the same and superior performance when transcribing the average-length PIREPs than Braina and Dragon. All SRSs had equal performance at transcribing the short-length PIREPs. Dragon, Google, LilySpeech, and Transcribe had the same performance and superior when transcribing the long-length PIREPs than Braina. Additionally, we found that the short, average, and long-length transcriptions for all 5 commercial off-the-shelf (COTS) SRSs provided readable information for flight service stations (FSS) to enter valuable weather information into the PIREP system

A Multi-Season Study of the Effects of MODIS Sea-Surface Temperatures on Operational WRF Forecasts at NWS Miami, FL

Studies at the Short-term Prediction Research and Transition (SPORT) Center have suggested that the use of Moderate Resolution Imaging Spectroradiometer (MODIS) sea-surface temperature (SST) composites in regional weather forecast models can have a significant positive impact on short-term numerical weather prediction in coastal regions. Recent work by LaCasse et al (2007, Monthly Weather Review) highlights lower atmospheric differences in regional numerical simulations over the Florida offshore waters using 2-km SST composites derived from the MODIS instrument aboard the polar-orbiting Aqua and Terra Earth Observing System satellites. To help quantify the value of this impact on NWS Weather Forecast Offices (WFOs), the SPORT Center and the NWS WFO at Miami, FL (MIA) are collaborating on a project to investigate the impact of using the high-resolution MODIS SST fields within the Weather Research and Forecasting (WRF) prediction system. The project's goal is to determine whether more accurate specification of the lower-boundary forcing within WRF will result in improved land/sea fluxes and hence, more accurate evolution of coastal mesoscale circulations and the associated sensible weather elements. The NWS MIA is currently running WRF in real-time to support daily forecast operations, using the National Centers for Environmental Prediction Nonhydrostatic Mesoscale Model dynamical core within the NWS Science and Training Resource Center's Environmental Modeling System (EMS) software. Twenty-seven hour forecasts are run dally initialized at 0300, 0900, 1500, and 2100 UTC on a domain with 4-km grid spacing covering the southern half of Florida and adjacent waters of the Gulf of Mexico and Atlantic Ocean. Each model run is initialized using the Local Analysis and Prediction System (LAPS) analyses available in AWIPS. The SSTs are initialized with the NCEP Real-Time Global (RTG) analyses at 1/12deg resolution (approx.9 km); however, the RTG product does not exhibit fine-scale details consistent with its grid resolution. SPORT is conducting parallel WRF EMS runs identical to the operational runs at NWS MIA except for the use of MODIS SST composites in place of the RTG product as the initial and boundary conditions over water, The MODIS SST composites for initializing the SPORT WRF runs are generated on a 2-km grid four times daily at 0400, 0700, 1600, and 1900 UTC, based on the times of the overhead passes of the Aqua and Terra satellites. The incorporation of the MODIS SST data into the SPORT WRF runs is staggered such that SSTs are updated with a new composite every six hours in each of the WRF runs. From mid-February to July 2007, over 500 parallel WRF simulations have been collected for analysis and verification. This paper will present verification results comparing the NWS MIA operational WRF runs to the SPORT experimental runs, and highlight any substantial differences noted in the predicted mesoscale phenomena for specific cases