1. 1 National Center for Atmospheric Research Boulder, CO October 21, 2005 Andy Stern Consulting Meteorologist Mitretek Systems Metadata for RWIS

2. 2 What is Metadata? Metadata is defined as “data about data” Metadata is a necessary component for observations to be included in data collecting networks (such as MADIS) Some portions of metadata can change frequently, so it is important for end users to understand the circumstances under which the data were collected

3. 3 What is Metadata used for? Metadata can describe almost any quality about an observation. Some examples include: –Platform location & elevation –The types & makes of sensors –Calibration records –Maintenance records –Site exposure

4. 4 Minimum Metadata for ESS From a MADIS data table: –|MN001|Twin Lakes I-35 Mile Post 1 –|371.1000|43.50833|-93.35406|GMT| Station Name/Identifier (5 characters) Long Name String (35 characters) Station Latitude/Longitude (to 5 digits) Station Elevation (to 4 digits) Time Basis (Greenwich Mean Time)

5. 5 State DOTs Providing Data to MADIS

6. 6 Expanded Metadata - Identification Platform ID/Site Number Plain Text Location Latitude/Longitude/Elevation Access Directions Datum RPU Make Nearest AWOS/ASOS Site Advanced Traffic Management Systems ID

7. 7 Metadata - Instrumentation Type & Model of each instrument Number of road sensors Puck layout diagram Location of sub-grade temperature probe Sensors in bridge decks/ramps Maintenance/Calibration Records

8. 8 Graphical Metadata RWIS I-80 EB Puck Layout Diagram

9. 9 Metadata – Site Exposure Digital Image of Site Digital Panoramic View of Site Distance to center of road Obstructions (direction & distance) Landscape Features Four Quadrant Site Layout Terrain Slope (degrees & direction) Base Height Above/Below the Roadway

10. 10 Example of Digital Panorama Interstate 80 @ Wahsatch, Utah

11. 11 Metadata value to the community Other communities (such as weather, energy, CVO, agriculture) can use metadata to determine if the observations are: –representative for their task –have appropriate exposure –have a robust maintenance policy –have an established climate record

12. 12 Additional Information New Publication from FHWA –“Road Weather Information System Environmental Sensor Station Siting Guidelines” –Partnership between FHWA, Aurora Pooled Fund Program and the AASHTO Snow and Ice Cooperative Program –Available from http://ops.fhwa.dot.gov/publications/ess05/