Data Record

0

cone_angle
cone angle
The apex angle of the
conical scan of aatsr, in
radians. This is the angle
between the line of sight
and the scan axis.

radians 
1 
fl 
4 byte(s) 
1

mir_off
mirror offset
angle The
azimuthal offset of the scan
from its nominal position,
in radians. This is the
angle between the nominal
and actual mirror
positions a the start of the scan.

radians 
1 
fl 
4 byte(s) 
2

x_misalign_corr
x misalignment
correction One of
the three angles that define
the misalignment between the
instrument and the
spacecraft. The misalignment
is specified by
the angular rotations about
three orthogonal axes
required to bring the
instrument into nominal
alignment with the
spacecraft
platform. This is the
rotation about the x axis,
in radians.

radians 
1 
fl 
4 byte(s) 
3

y_misalign_corr
y misalignment
correction One of
the three angles that define
the misalignment between the
instrument and the
spacecraft. The misalignment
is specified by
the angular rotations about
three orthogonal axes
required to bring the
instrument into nominal
alignment with the
spacecraft
platform. This is the
rotation about the x axis,
in radians.

radians 
1 
fl 
4 byte(s) 
4

z_misalign_corr
z misalignment
correction One of
the three angles that define
the misalignment between the
instrument and the
spacecraft. The misalignment
is specified by
the angular rotations about
three orthogonal axes
required to bring the
instrument into nominal
alignment with the
spacecraft
platform. This is the
rotation about the x axis,
in radians.

radians 
1 
fl 
4 byte(s) 
5

aocs_cx
AOCS parameter
Cx The AOCS
rotation amplitude in pitch.
This defines the rotation in
pitch applied by the ENVISAT
attitude control system in
yaw steering mode,
according to the formulae
set out in the Mission
Conventions Document (GS0561).

deg. 
1 
db 
8 byte(s) 
6

aocs_cy
AOCS parameter
Cy The AOCS
rotation amplitude in roll.
This defines the rotation in
roll applied by the ENVISAT
attitude control system in
yaw steering mode,
according to the formulae
set out in the Mission
Conventions Document (GS0561).

deg. 
1 
db 
8 byte(s) 
7

aocs_cz
AOCS parameter
Cz The AOCS
rotation amplitude in yaw.
This defines the rotation in
yaw applied by the ENVISAT
attitude control system in
yaw steering mode,
according to the formulae
set out in the Mission
Conventions Document (GS0561).

deg. 
1 
db 
8 byte(s) 
8

aocs_pitch_mis
AOCS pitch
mispointing The
constant component of pitch
error (if any) of the
ENVISAT attitude control
system in yaw steering mode.
This is applied as a
correction during geolocation.

deg. 
1 
db 
8 byte(s) 
9

aocs_roll_mis
AOCS roll
mispointing The
constant component of roll
error (if any) of the
ENVISAT attitude control
system in yaw steering mode.
This is applied as a
correction during geolocation.

deg. 
1 
db 
8 byte(s) 
10

aocs_yaw_mis
AOCS yaw
mispointing The
constant component of yaw
error (if any) of the
ENVISAT attitude control
system in yaw steering mode.
This is applied as a
correction during geolocation.

deg. 
1 
db 
8 byte(s) 
11

earth_maj_axis
EARTH_MAJOR_AXIS
The semimajor axis of
the geodetic reference
ellipsoid used for AATSR
image geolocation. For the
WGS 84 ellipsoid it is
6378.137 km.

km 
1 
db 
8 byte(s) 
12

atrk_samp_int
Alongtrack
sampling interval
Redundant parameter, no
longer used.

km 
1 
db 
8 byte(s) 
13

uni_time
Uniform time
step The time
interval corresponding to 1
granule, or 32 scans. This
is 32 times the scan
interval, or 32 times 150
ms, expressed in
days. It defines the
internal sampling interval
used by the geolocation algorithm.

days 
1 
db 
8 byte(s) 
14

img_row
Number of image
rows per granule
This parameter defines
the length of the product
granule in image rows; the
adopted value is 32.

 
1 
sl 
4 byte(s) 
15

grid_row
Number of grid
rows This is an
upper limit on the number of
product granules in an
orbit, used internally by
the Operational Processor to
determine the
range of times to be used to
derive geolocation tables.

 
1 
sl 
4 byte(s) 
16

disp_tabl
Displacement of
table start before ascending
node Because the
forward view of the AATSR
instrument is displaced by
approximately 900 km from
the nadir view, the data
processing for an
orbit must start with
instrument scans measured
when the satellite is still
some 900 km south of the
equator, before the
ascending node,
and the internal lookup
tables used by the
geolocation algorithm must
allow for this. This
parameter defines the number
of granules prior
to the ascending node
crossing that must be
catered for by the internal
tables to permit forward
view data on the
equator to be geolocated.
The current adopted value is 30.

 
1 
sl 
4 byte(s) 
17

ecc_ellip
eccentricity of
ellipsoid The
eccentricity of the geodetic
reference ellipsoid used for
AATSR image geolocation. For
the WGS 84 ellipsoid it is 0.0818191908426.

 
1 
db 
8 byte(s) 
18

geo_para
Geodetic
parameter (square of
��second
eccentricity��)
The square of the
geodetic parameter known as
the ��second
eccentricity��
of the adopted reference
ellipsoid. For the WGS 84
ellipsoid it is 0.00673949674227.

 
1 
db 
8 byte(s) 
19

spare_1
Spare 
 
1 
SpareField 
8 byte(s) 
20

fst_nad_pix
FIRST_NADIR_PIXEL_NUMBER
Absolute pixel index
corresponding to the first
element of the internal
pixel arrays for nadir view.
This index is internal to
the Operational
Processor; it is not fixed
by the actual pixel
selection map, and does not
impact on the format or
scientific contents of
the AATSR products.

 
1 
sl 
4 byte(s) 
21

fst_for_pix
FIRST_FORWARD_PIXEL_NUMBER
Absolute pixel index
corresponding to the first
element of the internal
pixel arrays for forward
view. This index is internal
to the Operational
Processor; it is not fixed
by the actual pixel
selection map, and does not
impact on the format or
scientific
contents of the AATSR products.

 
1 
sl 
4 byte(s) 
22

est_scan_pos_nad
Estimate of
relative scan position, nadir
scan The time
interval (expressed in days)
corresponding to the along
track displacement of the
nadir instrument scan at the
swath edge from
the subsatellite point. (It
is, in other words, the
linear displacement divided
by the satellite velocity.)
This parameter is
internal to the Operational
Processor; it is used to
initialise an iteration
within the geolocation
algorithm, and the output
product should be
independent of the actual
value of this parameter.

days 
1 
db 
8 byte(s) 
23

est_scan_pos_for
Estimate of
relative scan position, forward
scan The time
interval (expressed in days)
corresponding to the along
track displacement of the
nadir instrument scan at the
swath edge from
the subsatellite point. (It
is, in other words, the
linear displacement divided
by the satellite velocity.)
This parameter is
internal to the Operational
Processor; it is used to
initialise an iteration
within the geolocation
algorithm, and the output
product should be
independent of the actual
value of this parameter.

days 
1 
db 
8 byte(s) 
24

algtrk_ip_int
Alongtrack
interpolation interval
The alongtrack
separation of tie points
used internally for geolocation.

 
1 
ss 
2 byte(s) 
25

acrtrk_ip_it
Acrosstrack
interpolation interval
The acrosstrack
separation of tie points
used internally for geolocation

 
1 
ss 
2 byte(s) 
26

eps_x
Regridding
perturbation (eps_x)
An acrosstrack tolerance
used internally by the
regridding algorithm (qv.)
The value is set to optimise
the efficiency of the
regridding algorithm.

m 
1 
ss 
2 byte(s) 
27

eps_y
Regridding
perturbation (eps_y)
An alongtrack tolerance
used internally by the
regridding algorithm (qv.)
The value is set to optimise
the efficiency of the
regridding algorithm.

m 
1 
ss 
2 byte(s) 
28

long_off_flag
Longitude offset
flag (0=no offset)
This flag is provided for
system integration testing,
and will be set to zero
(off) in normal operational processing.

flag 
1 
sl 
4 byte(s) 
29

long_off
Longitude offset
(for system testing)
This parameter is an
offset applied to the
landsea mask if the
longitude offset flag is
nonzero. This parameter is
provided only for
use in system integration
testing, and is not relevant
to operational product generation.

(1e6) degrees 
1 
GeoCoordinate 
4 byte(s) 
30

spare_2
Spare 
 
1 
SpareField 
8 byte(s) 