Multi-Agency Profiler (CAP) Dataset
DescriptionWind profilers are Doppler radars used to measure vertical profiles of atmospheric winds directly above the profiler site. Typical operation of a wind profiler results in a vertical stack of winds every 30 minutes or hour. With the addition of an optional Radio Acoustic Sounding System (RASS), virtual temperature profiles can also be obtained. There are basically three types of radar wind profilers:
The MADIS Multi-Agency Profiler (MAP) dataset consists of data from a variety of these observing systems, which are collected from many different "providers" and integrated into a single dataset. Many of the MAP stations additionally report surface data which are available in the MADIS Meteorological Surface dataset. See the "Current Station Table" link below to see which stations have surface data.
- Boundary layer profilers (BLP) are small, relatively low-cost UHF Doppler radars used primarily to measure vertical profiles of horizontal winds. The BLPs have a minimum range of about 100 m above ground level (AGL), with range resolutions selectable from 60 m to 400 m. Depending on the configuration of the radar, and the atmospheric conditions, BLPs are capable of measuring wind up to about 3 km AGL. With the RASS addition, virtual temperature profiles up to about 1 km can also be obtained.
- Lower-tropospheric profilers typically measure winds from near the earth's surface to above the tropopause. RASS measurements can generally be obtained to 4-6 km AGL.
- Upper-tropospheric profilers, such as the ones operated by ESRL's Physical Sciences Division (PSD) in the Pacific Ocean, can measure profiles up to about 20 km AGL.
Geographic CoverageMost of the MAP stations are located in the United States and Canada, although there are several stations from NOAA's Aeronomy Laboratory that operate in the South Pacific, and a large network of stations are available from Japan.
Data ScheduleIncoming data are processed every 15 minutes. The data are segmented into half-hourly files, with the file for hour HH minute 00 containing data for HH-1:31-HH:00, and the file for hour HH minute 30 has reports for HH:01-HH:30 (e.g., the 1200 file has data from 11:31-12:00, and the 1230 file has data from 12:01-12:30). Some reports arrive late, so each hour's data is reprocessed a number of times. The most complete data for a given hour is available about 2-3 hours after the observation times. Using hour 00 as the example, the 0000 and 0030 files are generally processed and available at 00:19, 00:36, 00:53, 01:31, 01:42, 02:00, and 03:05.
VolumeTypical daily volume for all MADIS datasets can be seen here.
RestrictionsNo restrictions. All observations are publicly accessible.
Last updated 8 September 2017