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CLEM LWIR Calibrated Data (RDR)

Calibrated Data (RDR – Reduced Data Record)

PDS Data Set ID: CLEM1-L-LWIR-3-RDR-V1.0DOI: 10.17189/1519517

PDS4 Bundle:urn:nasa:pds:clementine_lwir_btDOI: 10.17189/52v5-ks05

For more information about LWIR Calibrated RDR products, see the Data Set Catalog File.

The Long Wavelength Infrared camera (LWIR) Calibrated (RDR) data products are images where the observed radiance has been converted to brightness temperature, which provides information on various physical properties of the lunar surface.

The LWIR camera has a single passband of width 1.5 microns centered at a wavelength of 8.75 microns. The LWIR spatial resolution ranged from 200 m/pixel near the poles to 55 m/pixel at the equator. Contiguous pole to pole imaging strips were obtained with approximately 10% overlap between adjacent frames. However, significant longitude gaps exist between successive orbit passes. During the systematic mapping phase of the Clementine mission, approximately 220,000 thermal-infrared images of the lunar surface were obtained.

RDR processing contained 6 steps:

  1. Converting measured data number (DN) values to radiance values

  2. Identifying and eliminating bad pixels

  3. Correcting for pixel response variation across the detector array

  4. Determining the zero-flux background of the instrument

  5. Comparing LWIR measured radiance of the Apollo 17 landing site to in situ temperature measurements in order to derive absolute calibration adjustments

  6. Converting measured radiance values to brightness temperatures via the Planck function (see Lawson et al., 2000, doi:10.1029/1999JE001047)

LWIR RDR image products have the following file names:

BTxxxxynnn.IMG

where:

BT = file type = Brightness Temperature image

xxxx = frame sequence number

y = latitude bin; this character gives a latitude range on the lunar surface where the observation was made; the center latitude defines the character (see the table below)

nnn = revolution number

LWIR RDR calibration image products have the following file names:

ttnnnyy.IMG

where:

ff = file type

FF = Flat Field image

BP = Bad Pixel image

nnn = revolution number

yy = letter code of first and last latitude bin that applies to the image

In ODE, RDR products have one of the following product IDs:

BTXXXXYNNN.IMG

TTNNNYY.IMG

Latitude bin for lunar mapping observations:

Character

Definition

A

-90 to -80

B

-80 to -70

C

-70 to -60

D

-60 to -50

E

-50 to -40

F

-40 to -30

G

-30 to -20

H

-20 to -10

I

-10 to 0

J

0 to 10

K

10 to 20

L

20 to 30

M

30 to 40

N

40 to 50

O

50 to 60

P

60 to 70

Q

70 to 80

R

80 to 90

S

“unknown” targets

T

Earth observations prior to systematic mapping

U

Sky observations prior to systematic mapping

V

Lunar observations prior to systematic mapping

W

Sky observations after systematic mapping

Y

Earth observations after systematic mapping

Z

Lunar observations after systematic mapping