Kavaya-1

Proposal for 2008 Version of the Wind Measurement Requirements

Michael J. KavayaNASA Langley Research Center

michael.j.kavaya@nasa.gov

Working Group on Space-Based Lidar WindsMonterey, California USA

5 – 8 February 2008

Kavaya-2

WMO 1996 Wind Measurement Requirements

Sensing Depth 0-20 km

Wind Speed Error21

100 to 5 hPaSurface to 100 hPa m/s

Wind Direction Error2.5 deg5 deg

Speed > 15 m/sSpeed < 15 m/s

deg

0

100

200

300

400

500

600

700

800

900

1000

1100

0

1000200030004000500060007000800090001000011000120001300014000150001600017000180001900020000210002200023000240002500026000270002800029000300003100032000330003400035000

Altitude (m)

Pressure (hPa)

Kavaya-3

NPOESS/IPO 28 June 1996 Wind Measurement Requirements

Threshold Objective

Sensing Depth 0-20 0-20 km

Vertical Sampling IntervalIn any clouds & for PBL, aerosol

returns0.1

km

Horizontal Resolution 200 50 km

Velocity Error, Vector 2 0.5 m/s

Temporal Resolution 12 1 hour

+

++

+

Kavaya-4

NASA/NOAA GTWS Wind Measurement Requirements (Partial List)Posted on Web on 16 Oct. 2001

Threshold Objective

Vertical Depth of Regard (DOR) 0-20 0-30 km

Vertical Resolution: Tropopause To Top of DOR Top of BL To Tropopause Surface To Top of BL (~2 km)

N/A1

0.5

20.5

0.25

kmkmkm

Horizontal ResolutionA 350 100 km

Number of HorizontalA Wind TracksB 4 12 -

Number of Collocated LOS Wind Measurements for HorizontalA Wind Calculation

2 = pair 2 = pair -

Velocity ErrorC Above BL In BL

33

21

m/sm/s

Temporal Resolution 12 6 hour

Minimum Wind Measurement Success RateD 50 50 %A Horizontal winds are not actually calculated; rather two LOS winds with appropriate angle spacing and collocation are measured for an “effective” horizontal wind measurement. The two LOS winds are reported to the user. B The 4 cross-track measurements do not have to occur at the same along-track coordinate; staggering is OK. C Error = 1 LOS wind random error, projected to a horizontal plane; from all lidar, geometry, pointing, atmosphere, and signal processing effects. The true wind is defined as the linear average, over a 100 x 100 km box centered on the LOS wind location, of the true 3-D wind projected onto the lidar beam direction provided with the data. DScored per vertical layer per LOS measurement not counting thick clouds

++

+

+

Kavaya-5

NASA/NOAA GTWS Wind Measurement Requirements (Partial List)Posted on Web on 16 Oct. 2001 – Errata Added Later

Threshold Objective

Minimum Vertical Depth of Regard (DOR) 0-20 0-30 km

Maximum Vertical Resolution: Tropopause to Top of DOR Top of BL to Tropopause (~12 km) Surface to Top of BL (~2 km)

N/A1

0.5

20.5

0.25

kmkmkm

Maximum Horizontal ResolutionA 350 100 km

Minimum Number of HorizontalA Wind TracksB 4 12 -

Minimum Number of Collocated LOS Wind Measurements for HorizontalA Wind Calculation

2 = pair 2 = pair -

Maximum Velocity ErrorC Above BL In BL

32

21

m/sm/s

Maximum Temporal Resolution (N/A for Single S/C) 12 6 hour

Minimum Wind Measurement Success RateD 50 50 %A Horizontal winds are not actually calculated; rather two LOS winds with appropriate angle spacing and collocation are measured for an “effective” horizontal wind measurement. The two LOS winds are reported to the user. B The 4 cross-track measurements do not have to occur at the same along-track coordinate; staggering is OK. C Error = 1 LOS wind random error, projected to a horizontal plane; from all lidar, geometry, pointing, atmosphere, signal processing, and sampling effects. The true wind is defined as the linear average, over a 100 x 100 km box centered on the LOS wind location, of the true 3-D wind projected onto the lidar beam direction provided with the data. DScored per vertical layer per LOS measurement not counting thick clouds

+

Kavaya-6

NASA/NOAA GTWS Wind Measurement Requirements (Partial List)Modified in 2005-2006 during NASA Lidar Technologies WG

Demo Threshold Objective

Minimum Vertical Depth of Regard (DOR) 0-20 0-20 0-30 km

Maximum Vertical Resolution: Tropopause to Top of DOR Top of BL to Tropopause (~12 km) Surface to Top of BL (~2 km)

N/A21

N/A1

0.5

20.5

0.25

kmkmkm

Maximum Horizontal ResolutionA 350 350 100 km

Minimum Number of HorizontalA Wind TracksB 2 4 12 -

Minimum Number of Collocated LOS Wind Measurements for HorizontalA Wind Calculation

2 = pair 2 = pair 2 = pair -

Maximum Velocity ErrorC Above BL In BL

32

32

21

m/sm/s

Maximum Temporal Resolution (N/A for Single S/C) N/A 12 6 hour

Minimum Wind Measurement Success RateD 50 50 50 %A Horizontal winds are not actually calculated; rather two LOS winds with appropriate angle spacing and collocation are measured for an “effective” horizontal wind measurement. The two LOS winds are reported to the user. B The 4 cross-track measurements do not have to occur at the same along-track coordinate; staggering is OK. C Error = 1s LOS wind random error, projected to a horizontal plane; from all lidar, geometry, pointing, atmosphere, signal processing, and sampling effects. The true wind is defined as the linear average, over a 100 x 100 km box centered on the LOS wind location, of the true 3-D wind projected onto the lidar beam direction provided with the data. DScored per vertical layer per LOS measurement not counting thick clouds

+

Demo addition approved by NASA/NOAA GTWS SDT and by NASA HQ SMD ESD

Kavaya-7

Yet More Changes

• External Peer Review of Laser/Lidar Work at LaRC in Oct. 2007

• Criticized for not having technology path to all 3 sets of requirements

• Criticized for showing requirements with “old” date of 2001

• Criticized for N/A’s listed for vertical resolution

• Wayman Baker and others suggested sending Objective requirements to oblivion,

leaving Demo and Threshold

• Wayman Baker suggested 4 and 3 km for the vertical resolution requirement from 12 to

20 km for the Demo and Threshold missions, respectively

• The NRC Earth Science Decadal Survey was published in Jan. 2007. It recommended

two wind missions, “Demonstration” in 2016 and “Operational Demonstration”

in 2022.

• Wayman Baker and others suggested renaming the NASA/NOAA GTWS “Demo” to

“Science Demonstration”, and renaming “Threshold” to “Operational”

• May we have consensus on all these changes and call them the NASA/NOAA 2008

requirements?

Kavaya-8

NASA/NOAA Wind Measurement RequirementsPart 1 of 3

Science Demonstration

Operational

Minimum Vertical Depth of Regard (DOR) 0-20 0-20 km

Maximum Vertical Resolution: Tropopause to Top of DOR Top of BL to Tropopause (~12 km) Surface to Top of BL (~2 km)

421

31

0.5

kmkmkm

Maximum Horizontal ResolutionA 350 350 km

Minimum Number of HorizontalA Wind TracksB 2 4 -

Minimum Number of Collocated LOS Wind Measurements for HorizontalA Wind Calculation

2 = pair 2 = pair -

Maximum Velocity ErrorC Above BL In BL

32

32

m/sm/s

Minimum Wind Measurement Success RateD 50 50 %A Horizontal winds are not actually calculated; rather two LOS winds with appropriate angle spacing and collocation are measured for an “effective” horizontal wind measurement. The two LOS winds are reported to the user. B The 4 cross-track measurements do not have to occur at the same along-track coordinate; staggering is OK. C Error = 1 LOS wind random error, projected to a horizontal plane; from all lidar, geometry, pointing, atmosphere, signal processing, and sampling effects. The true wind is defined as the linear average, over a 100 x 100 km box centered on the LOS wind location, of the true 3-D wind projected onto the lidar beam direction provided with the data. DScored per vertical layer per LOS measurement not counting thick clouds

ObjectiveRequirements

Kavaya-9

BACKUP

Kavaya-10

NASA/NOAA 2008 Wind Measurement Requirements

ScienceDemonstration Mission

Operational Mission

Current Horizontal Wind Vertical Profile Observations

~23 km

• Global averages• If 2 measurements in a box, pick best one• Emphasis on wind profiles vs. height

Courtesy Dr. G. David EmmittNote different color key

2

20

0

100%0

12

50%

< 3 m/s, 3 km

< 2 m/s, 0.5 km

< 3 m/s, 1 km

≈

33%

Thick clouds

No Vector Wind Measurement

Required Minimum Success

Rate

Vector Wind Measurement Success Rate

Altitude (km)

Vector Wind Measurement Success Rate

Altitude (km)

2

20

0

100%0

12

50%

< 3 m/s, 2 km

< 3 m/s, 4 km

≈

33%

No Vector Wind MeasurementThick clouds

Required Minimum Success

Rate

< 2 m/s , 1 km

Kavaya-11

Pulsed Doppler Wind Lidar Concept

Science Mission Operational Mission

NRC 2007 Earth Science

Decadal Survey

Recommended

Demonstration “3-D Winds”

Mission in 2016

NRC 2007 Earth Science

Decadal Survey

Recommended

Operational “3-D Winds”

Mission in 2022