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BK
SKYBACK fits a two-dimensional surface of degree up to 10
to the sky background of a map. For input, one can use the TV cursor-
box to define an arbitrary number of regions or one can input just one
area manually. Provision is made for ignoring edited areas (zero values)
or applying a weighting file. The mean or the most probable value can
be used when using the TV cursor box. For output, there are three
choices: one may compute the best fit to the sky values in the map and
produce a new map of the best fitted surface (one may subtract the average
sky from this if desired); one may produce a new map
with the surface subtracted from the original map and the average
sky added to it; or one may do both.
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Enter an option: 7-NOV-2000 20:04:40.20
OPTION=BK
SKYBACK, Version 4
Open the file to be fitted
Enter the filename: (<CR> for default)
FILE=sky
There is one map in the file
Reading from the file
150 rows of 150 pixels in R4 format
Open the output file
Enter the filename: (<CR> for default)
OUTPUT_FILE=SKY2
Writing to an existing file
There is one map in the file
Enter the map number: (default = one after the last map)
MAP=1
250 rows of 250 pixels in R4 format
Enter a command:
F = Produces a fit to the sky background and writes it to
the output file (default). The average of the fit may be
subtracted if desired.
S = Produces a fit to the sky background, subtracts it from the original
data, adds the average of the fit, and writes it to the output file
B = Does both commands F and S (requires opening a second output file)
COMMAND=
F
Do you want to subtract the average of the fit from
the sky output file? (default = N)
SUBTRACT=
F
Enter the degree of the fit: 1 = plane (default),
2 = paraboloid, etc.; 10 = maximum
DEGREE=2
Enter an input method:
AS = Position from cursor; SAOimage already loaded
S = Position from cursor; need to load SAOimage
M = Manual input of boundaries of only one rectangle (default)
from which a fit will be obtained
INPUT_METHOD=S
Select a frame buffer size:
1 = 512 X 512 (default)
2 = 800 X 800
3 = 1024 X 1024
4 = 1600 X 1600
5 = 2048 X 2048
6 = 4096 X 4096
7 = 4096 X 1024
8 = 1024 X 4096
9 = 1144 X 880
10 = 1144 X 764
11 = 128 X 128
12 = 256 X 256
13 = 90 X 90
FRAME_BUFFER=
1
Enter start-column end-column start-row end-row: (default = entire map)
BOUNDARIES=
1
150
1
150
The upper left corner of the frame buffer is (0, 0)
Enter the starting location of the lower left corner
of the map boundary in the frame buffer:)
(default = map centered in frame buffer)
LOWER_LEFT=
181
330
Enter the minimum and maximum intensities: (defaults = 0 1000)
MINIMUM_MAXIMUM=100 300
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 372 417
X, Y: in frame = 187.500 326.500
X, Y: in map = 7.500 5.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 384 403
X, Y: in frame = 199.500 312.500
X, Y: in map = 19.500 19.500
Most probable value is being computed
Most probable value = 104.7919 , Mean error = 0.3145860
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 430 416
X, Y: in frame = 245.500 325.500
X, Y: in map = 65.500 6.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 442 404
X, Y: in frame = 257.500 313.500
X, Y: in map = 77.500 18.500
Most probable value is being computed
Most probable value = 107.4238 , Mean error = 0.3342307
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 375 391
X, Y: in frame = 190.500 300.500
X, Y: in map = 10.500 31.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 388 379
X, Y: in frame = 203.500 288.500
X, Y: in map = 23.500 43.500
Most probable value is being computed
Most probable value = 106.7709 , Mean error = 0.4963088
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 373 296
X, Y: in frame = 188.500 205.500
X, Y: in map = 8.500 126.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 390 278
X, Y: in frame = 205.500 187.500
X, Y: in map = 25.500 144.500
Most probable value is being computed
Most probable value = 105.0997 , Mean error = 0.4154976
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 430 290
X, Y: in frame = 245.500 199.500
X, Y: in map = 65.500 132.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 450 278
X, Y: in frame = 265.500 187.500
X, Y: in map = 85.500 144.500
Most probable value is being computed
Most probable value = 107.2519 , Mean error = 0.2116412
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 495 288
X, Y: in frame = 310.500 197.500
X, Y: in map = 130.500 134.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 508 277
X, Y: in frame = 323.500 186.500
X, Y: in map = 143.500 145.500
Most probable value is being computed
Most probable value = 104.8125 , Mean error = 0.3249300
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 492 358
X, Y: in frame = 307.500 267.500
X, Y: in map = 127.500 64.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 508 336
X, Y: in frame = 323.500 245.500
X, Y: in map = 143.500 86.500
Most probable value is being computed
Most probable value = 107.9783 , Mean error = 0.6838021
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 488 414
X, Y: in frame = 303.500 323.500
X, Y: in map = 123.500 8.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 503 397
X, Y: in frame = 318.500 306.500
X, Y: in map = 138.500 25.500
Most probable value is being computed
Most probable value = 105.4514 , Mean error = 0.4384751
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
Lower left: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 379 355
X, Y: in frame = 194.500 264.500
X, Y: in map = 14.500 67.500
Upper right: Cursor in image 1; file name = SKY2
X, Y: on TV desktop = 395 336
X, Y: in frame = 210.500 245.500
X, Y: in map = 30.500 86.500
Most probable value is being computed
Most probable value = 108.7861 , Mean error = 0.3564392
Be sure SAOimage has focus; position cursor at the lower left corner and
press <CR>; then position the cursor at the upper right corner and press <CR>
(or type 0 to continue, - to delete the last set of pixels)
The weighted average of the cursor box values of the sky = 106.463959
The two-dimensional fit has been completed
The mean error for an observation of average weight = 1.97768
Please wait ... ! This can be a long time for high degrees
The average sky for the entire output map = 101.898
TERM COEFFICIENT
X**0Y**0 104.722 +- 6.84823
X**1Y**0 0.795727E-01 +- 10.2947
X**2Y**0 -0.597745E-03 +- 5.28115
X**0Y**1 0.164388E-01 +- 13.3588
X**1Y**1 0.783934E-04 +- 4.02087
X**0Y**2 -0.168991E-03 +- 7.57133
Enter an option: 7-NOV-2000 20:05:30.58
OPTION=
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