Lead Scientist | P. Black |
AXBT Scientists | E. Uhlhorn/C. Valde |
Radar scientist | M. Black |
GPS Dropsonde | M. Black |
HRD Workstation | M. Black |
Scripps laser altimeter | P. Matusov |
Scripps sonobuoy | P. Matusov |
Scripps digital imager | P. Matusov |
FRD BAT probe | S. White |
SCR | not operating |
PMS/CIP probes | not installed |
Mission Briefing:
This mission was designed to inter-compare aircraft flight level
instrumentation between the two NOAA aircraft, to flight test new
CBLAST instrumentation, to test the hurricane planetary boundary
layer (PBL) flight pattern and to execute BAT probe calibration
maneuvers.
Mission Synopsis
Detailed mission briefings were held with AOC flight directors
the day before the flight to discuss any problems with the
calibration flight segments being planned. A detailed briefing on
CBLAST, air sea and ocean winds hurricane flight patterns
followed with AOC flight crew. Two hours prior to the flight, a
second briefing with the flight crew was held to discuss the
flight profile.
The flight, delayed for two days by a defective prop hub,
departed AOC at MacDill AFB at 1400 UTC, Aug 23 and landed at
MacDill AFB at 19:45 UTC, Aug 23, a duration of 5.75 hours.
Flight altitudes were 10,000, 5,000 and 1,000 ft for formation
flying during the two-aircraft inter-comparison portion of the
flight. The aircraft flew 5-6 min legs outbound and inbound from
NDBC buoy 42003 in the east-central Gulf at two values of the
indicated airspeed: 220 kt (penetration airspeed) and 190 kt
(ocean probe deployment airspeed). The aircraft then descended to
600 ft during the cross wind flight legs of the PBL flight
pattern followed by legs at 3,500, 2,000, 1,000, 600, 400 and
200 ft during the along wind portion of the PBL pattern. The
flight altitude for the BAT wind circle and box calibration
maneuvers was 2,000 ft.
There were scattered cumulus congestus clouds in the area during
the mission. The surface wind was 5 kt from 110 deg.
Following the first downwind leg, 43RF departed the area to fly
through rain cells about 50-100 nm away. However, their mission
had to be cut short following failure of the UMASS IWRAP system.
Two problems were encountered: 1) a failed motor for rotating the
antenna systems and 2) a failure of the communications between
the processor and data recording systems.
The formation flying portion of the flight was executed
flawlessly. The aircraft approached to within about 100 ft of
each other with 42 just below and trailing 43 for the first two
altitudes and then switched positions for the final altitude. The
formation was held even in turns- a very impressive performance.
The boundary layer pattern was also executed extremely well.
However, one premature altitude change pointed to the need to
more clearly lay out the flight altitude and probe deployment
sequence. The aircraft coordination was carried out flawlessly as
was the sequence of GPS sonde, AXBT and sonobuoy deployments.
This included coordinating channel numbers for both AXBTs and
GPS sondes to prevent any probe transmission interference.
The main CBLAST instruments being tested on this flight were the
NOAA FRD BAT probe and IRGA systems for turbulence measurement
and the Scripps suite of instruments: the laser altimeter, the
downward digital camera system and the sonobuoy receiver. The BAT
probe and IRGA performed perfectly as did the Scripps systems.
The digital camera system was impressive to watch as it captured
images at a nominal 10 hz at the higher levels and at 20 hz at
the lower levels. All cad-launched and internal free-fall
launched sonobuoys functioned for the duration of the flight
following deployment. This was a pleasant surprise as previous
AOML users of the Navy surplus units had reported 70% failure.
This may have been due to improper hand-launching from a ship.
The Scripps data will be analyzed for any problems the coming
week. The BAT and IRGA data were written to a zip disc and will
be sent to Jeff French in Australia and Ed Dumas in Oak Ridge for
analysis.
The HRD SFMR still appeared to exhibit biases in near-zero wind
brightness temperatures. However, Pro Sensing had not yet
provided calibration updates from the previous weeks initial
test. Empirical biases were applied that will be used in high
wind environments as a default.
The real-time transmission of AXBT ocean temperature profiles and
computed ocean heat content were transmitted to NHC for the first
time. The system of real time despiking, smoothing and
significant level computation will continue to be tested this
season in high wind environments.
Problems:
All aircraft systems performed flawlessly, including expendable
probe deployment and processing systems. The HRD workstation
failed to communicate with AVAPS dropsonde system, AXBT system or
radar systems despite having done so during pre-flight checks.
This problem will be addressed on Monday or Tuesday following
arrival of HRD computer personnel.
The SRA system for directional ocean wave spectra, surface
elevation (storm surge) and low rain rates was not operated
despite intermittent data dropouts due to flawed automatic
frequency control (AFC). Ed Walsh had to return to base in
Boulder before the twice-delayed flight could be conducted.
The PMS and CIP particle measurement probes were not installed.
All are awaiting completion of the new wing pylon to mount the
probes. All electronics is installed and also awaiting pylon
completion and installation, now expected about Sept 15.
As mentioned above, the IWRAP system on NOAA42 failed. UMASS
engineers will continue working on the system during the coming
week.
One miscommunication resulted in a premature climb in the flight
pattern. Format and content of flight leg and expendable probe
deployment sequences will be revised to clarify these maneuvers.
Return to Mission page.