Boundary Layer Profilers also referred
to as BLPs 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 3-5 km AGL. With the addition
of an optional Radio Acoustic Sounding System (RASS), virtual
temperature profiles up to about 1 km can also be obtained.
Unlike the radars used in the NOAA Profiler Network, the CAPs sites are operated
in many different ways, are owned by about 30 different agencies, and are
optimized for different applications. Most BLPs report hourly winds,
although some may generate wind profiles as often as every 10 minutes.
The radars may be in fixed locations and operated continuously, or
they may be portable, and operated only during field campaigns.
Therefore, the list of profilers available via our Web displays will be
Normally, raw CAP data files are time-stamped using the starting time of their
acquisition period. Data time-stamps used for data displays on this site
are always the end-time of the acquisition period.
The winds displayed at each height are averaged over the preceding hour
(in the case of hourly winds), e.g., sub-hourly data processed between
1600-1700 UTC would be averaged and displayed with the time stamp of 1700 UTC.
The displayed winds have all "passed" our single-station quality control
requirements (continuity in height and time, and a requirement that good
vertical beam data is present) and typically represent high quality data.
RASS temperatures follow the same time stamp convention and have also passed
single-station quality control. BLP Web products are created based on
the reporting periods of a radars ranging from 1-hour to 10-minute cycles.
Generally hourly resolution data are available by 30 minutes past the hour,
and 30-minute resolution data are available 20 minutes past the end
of their cycle.