How NOAA is Improving Weather Forecasting with Commercial Radio Occultation (RO) Data

Background

NOAA fulfills its commitments to the Weather Research and Forecasting Innovation Act of 2017 by prioritizing research that improves weather modeling and computing capabilities, utilizing radio occultation (RO) data from commercial aerospace companies. The Weather Act drives improvements in weather forecasting and warning systems to build a responsive and resilient Weather-Ready Nation.

Spire Global provides industry-trusted space-based weather data using a proprietary constellation of low-orbit satellites, collecting real-time data from every layer of the atmosphere to improve weather-resiliency across all industries. Spire recognizes climate change as one of the world’s most significant challenges and is committed to filling a role that fosters positive change through data-backed intelligence.

Overview

NOAA has recognized commercially sourced RO data as a viable and cost-effective option to improve weather forecasting capabilities and enhance our understanding of climate change. For that reason, NOAA awarded Indefinite Delivery, Indefinite Quantity (IDIQ) contracts to commercial aerospace companies to deliver RO data for weather applications.

Before developing or awarding any contracts, a pilot program was used to assess the accuracy, reliability, and overall impact commercial RO data has on weather forecasting applications. The initial assessment of the pilot program found that “Spire’s Level 2 products were mature and stable, with only one minor revision to the delivered data”, and “The data produced a marked positive impact on the Day 1 forecast.” The cost-benefit analysis of the pilot program translated to high-value results, with room for increased growth potential.

Approach

On November 20, 2020, NOAA awarded its first RO data contracts to two commercial space firms – Spire Global and GeoOptics.

Spire was awarded a 2-year contract with a $23 million ceiling – culminating years’ worth of work to develop, manufacture, and operate satellites to collect atmospheric data for operational weather forecasts. Each contract was awarded alongside specific data quality requirements that each vendor must maintain to remain eligible. The requirements for each RO profile are as follows:

• Latency: All data must be delivered within 140 minutes of observation.
• Signal-to-Noise Ratio: SNR ratio must be greater than 200, averaged over the 60-80 km region.
• Extent: RO altitude extent must span from -150 to 90 km in straight line-of-sight altitude.
• Quantity: Each Delivery Order will have a minimum RO/day specification that must be met.
• Geographic Distribution: Spatial sampling of RO profiles must be globally distributed in latitude and longitude.

Results

NOAA commercial RO data Delivery Orders (DO) 1-4 were awarded on a per-contract basis using cost-benefit analysis, including stringent data accuracy and operational impact guidelines.

Delivery Order 1

On November 24, four days after the initial contracts were awarded, NOAA issued IDIQ ‘Delivery Order 1’ (DO-1) to Spire and GeoOptics – leaving each firm responsible for delivering RO data to meet or exceed data quantity, quality, and latency requirements.

Spire’s 24-hour sample data was successfully delivered on December 2, with the deliverables reaching 700 ROs/day – exceeding the minimum requirement of 500. Each RO profile met all contract data specifications and data latency requirements.

Delivery Order 2

In March 2021, NOAA awarded DO-2 to GeoOptics – a six-month contract to assess the impact of commercially-sourced RO data and ensure its suitability for weather operation applications.

As per the NOAA cost-benefit analysis report to congress, “An analysis of data from April 2 to May 20, 2021, showed that commercial RO profiles were found to agree well with ground-based measurements, other satellite observations, and model predictions. The initial data assimilation test, comparing forecasts with and without the commercial data, showed mixed results, implying a neutral to slightly positive impact with only very small amplitude changes, as anticipated given the relatively small quantity of data. Larger quantities of RO data are expected to have more significant impacts on the forecast models.”

Further, “The DO-2 commercial data were acquired for approximately one-quarter to half of the COSMIC2 price.”

Delivery Order 3

In August 2021, NOAA awarded DO-3 to Spire Global – a six-month contract that demanded a minimum of 3000 globally distributed ROs/day, with each profile meeting or exceeding data quality and latency requirements. The contract marked NOAA’s largest purchase of RO data under the Commercial Weather Data Buy Program, showing an increasingly high level of trust in commercial space data capabilities. All RO profiles met data specifications and data latency requirements upon delivery.

Delivery Order 4

On February 10, 2022, NOAA awarded DO-4 to Spire Global – a 308-day contract that increased Spire’s delivery capacity from 3000 to 5500 ROs/day. The award is valued at just over $8 million, making it the single largest US government purchase of commercial RO data to date. RO data delivery will begin on March 16, 2022, and run until January 18, 2023.