HTC
Tech Note E15
FEB 1988
R. W. Johnson
UC SAN DIEGO LIBRARY
The material contained in this note is to be considered
proprietary in nature and is not authorized for distribution
without the prior consent of the Marine Physical Laboratory
and the Air Force Geophysics Laboratory
PRELIMINARY OPERATIONS MANUAL
(1 Feb 88)
Prepared for
Air Force Geophysics Laboratory, Air Force Systems Command
United States Air Force, Hanscom AFB, Massachusetts 01731
WHOLE SKY IMAGER
(E/O Camera System 5)
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OCEANOGRAPHY MARINE PHYSICAL LAB San Diego, CA 92152-6400
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WHOLE SKY IMAGER
(E/O Camera System 5)
PRELIMINARY OPERATIONS MANUAL
(1 Feb 88)
This preliminary manual summarizes the basic support procedures required for the
normal operation of the Whole Sky Imager. It is intended as a checklist operational guide
for the use of on-site host personnel in performing their periodic inspection and assessment
of the system's performance.
System maintenance and trouble shooting instructions are not included in this
summary note, but are available under separate cover.
UCSD/MPL POINTS OF CONTACT
1. Richard W. Johnson, (619) 534-1772, AV 553-5800
2. John S. Fox, (619) 534-1770, AV 553-5800
3. Jack R. Varah, (619) 534-1768, AV 553-5800
150
...
....
.
.....
.
.
WHOLE SKY IMAGER
(E/O Camera System 5)
Table of Contents
1. System Description
2. Host Personnel Responsibilities
3. WSI Operational Checklists
a.
b.
c.
Daily Visual Inspections
Data Tape Replacements
Solar Attenuator Arm Replacement
List of Illustrations
HEEE
au AWNA
WSI Camera Assembly without shroud
WSI Control Console Assembly
WSI Camera Schematic
WSI System Block Diagram
E/O Camera Pedestal (Typical)
Solar Attenuator, Arm Change Schedule
Fig. 5
Fig. 6
Table A
Table B
WSI Data Site: Host Support Notes
Solar Attenuator, Arm Change Schedule
Page 1
WHOLE SKY IMAGER
..
..
.
(E/O Camera System 5)
1.
System Description
The basic Whole Sky Imager (
WSI) system is contained in two mechanical
assemblies. These assemblies are illustrated photographically in Figs 1 & 2, and as block
diagrams in Figs 3 & 4. The external and internal assemblies (Figs 1 & 2) are normally
interconnected by a set of 100 foot control cables which provide system power,
synchronization and data logging capability.
In its most basic form, each of these WSI systems consists of a computer controlled
solid-state video camera that provides calibrated, multi-spectral imagery suitable for the
automatic extraction of local contrast transmission and cloud cover information. Imbedded
within the control computer are prototype and proprietary extraction algorithms necessary
to provide these numerical products. In addition to radiometrically calibrated imagery,
advanced algorithms are available to provide near real-time products of the data acquisition,
processing and display sub-systems in the form of continuously updated digital
presentations of selected operational quantities. For the WSI task of generating cloud field
statistics, these algorithms are withheld from the field systems, and they are used only
during post-archival processing, thus each field system is operated in automatic data
acquisition and archival modes only.
An auxiliary mounting pedestal illustrated in Fig. 5 is associated with the WSI system
to provide a standardized base for the camera, and to provide some measure of
environmental control. The 2 ft X 2 ft insulated pedestal is 4 feet high and contains a 1500
watt, 5120 Btuh electric heater with built-in fan, and a 5000 Btuh air conditioner for
summer cooling. These heating and cooling units are automatically controlled by 115VAC
in-line thermostats which are mounted within the pedestal adjacent to the camera baseplate.

WHOLE SKY IMAGER
(E/O Camera System 5)
Page 2
340
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Fig. 1 WSI Camera Assembly, W/O Shroud

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(E/O Camera System 5)
WHOLE SKY IMAGER
Page 3
Fig. 2 WSI Control Console Assembly
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 4

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E/O CAMERA SYSTEM FOR
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Image Acquisition & Analysis System
Hardware Block Diagram E/O System 5
SONY PVM 1271 Q
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EXTERIOR SENSOR
INSTALLATION
INTERIOR CONTROLLER
INSTALLATION
(E/O Camera System 5)
WHOLE SKY IMAGER
Page 5

Fig. 4 WSI System Block Diagram
E/O CAMERA., W/ SHBRUD-
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....................
.......
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Fig. 5 E/O Camera Pedestal (Typical)
(E/O Camera System 5)
WHOLE SKY IMAGER
Page 6

.
;
.
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 7
Host Personnel Responsibilities
.
.
.
..
.
...
......
.....
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. 2..
The WSI system is designed to operate in automatic data acquisition and archival
modes with a minimum of operator interaction. Thus, once the system has been installed and
initialized by UCSD/MPL technical staff, it requires only those services outlined in Table A,..
"WSI Data Site: Host Support Notes.”.
.
....
.
The six tasks outlined in Table A can be further summarized into the several items
listed below.
1. Visually inspect control console video display DAILY. Report abnormalities.
II. Remove data tapes & replace whenever indicated on monitor.
a. On WEEKLY schedule if operation is normal.
b. As indicated in the event of system fault or power failure.
III. Weekly removal, cleaning and replacement of external computer air filter.
IV. Periodically substitute solar attenuator arms.
a. Change arms in accordance with schedule illustrated in Fig. 6.
V. Periodically inspect sensor housing and mounting pedestal. Report abnormali-
ties.
a. Open box to check thermostat settings and verify heater & A/C operation.
b. Note instrument purge pressure (optimum camera housing pressure is 2 - 3
psi.
c. General visual inspection of dome, occulter/attenuator and housing.
Checklists to assist in conducting the tasks listed above are provided in the follow-
ing section.
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 8
TABLE A
......
...
...
..04I
I
WSI DATA SITE: HOST SUPPORT NOTES
DURING DATA COLLECTION INTERVAL (ESTIMATED 2 YRS)
1.
Provide daily visual inspection of camera assembly. Wipe or brush optical dome
lightly if required to remove snow, heavy dew, thick dust, etc.
2. Provide daily visual inspection of console assembly. Observe video monitor to
determine normal image quality and solar attenuator position.
3. Provide weekly unloading and replacement of data cassette with subsequent mailing to
UCSD/MPL. (Cassettes provided by UCSD/MPL as well as procedural training).
4.
Provide periodic substitution of solar attenuator arms to compensate for seasonal
declination changes. (Change schedule and appropriate arms provided by
UCSD/MPL. Normal change cycle is at two week intervals, extending to twelve
weeks twice a year).
Provide telephone contact with UCSD/MPL in the event of system malfunction, and
assist in preliminary fault assessment.
6. Permit intermittent access to site by UCSD/MPL personnel to effect system
repair/replacement as required.
NOTE:
UCSD/MPL will provide written instruction manuals as required to assist host
personnel in accomplishing items listed above.
Page 9
WHOLE SKY IMAGER
(E/O Camera System 5)

Fig. 6 Attenuator Arm Change Schedule
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WHOLE SKY IMAGER
(E/O Camera System 5)
Page 10
TABLE B
SOLAR ATTENUATOR
Arm Change Schedule

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2 Feb
22 Feb
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WHOLE SKY IMAGER
(E/O Camera System 5)
Page 11
3. WSI OPERATIONAL CHECKLISTS (REF. TABLE A)
A. DAILY VISUAL INSPECTIONS
1. Camera Assembly
a. Wipe or brush optical dome lightly, if required.
b. Clear occultor drive of debris, if required.
C. Check pedestal stability & alignment.
2. Console Assembly
a. Check monitor for normal image quality.
b. Check monitor image for solar attenuator position, i.e., sun's image
within attenuator boundary.
c.
Check monitor for normal image cycle, i.e., four frame sequence and
stable standby.
d.
Check standby image for correct annotation, i.e., time/date and filter
ident.
Check solar attenuator position at LAN, i.e., support rod vertical,
solar image on vertical center line.
with
3. Accessory Control Panel
a. Indicator lights cycling normally.
b. Attenuator & Iris readouts changing normally
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 12
3.
cont ... WSI OPERATIONAL CHECKLIST (REF. TABLE A)
B. DATA TAPE REPLACEMENTS
The 8 mm tape cassette that is used in the EXB-8200 streaming tape drive is
designed to hold approximately 2.2 Gigabytes of data. This is in excess of the
amount normally expected from a continuous seven day data collection cycle.
Thus the normal operating procedure is to change data tapes every seven days
during the normal evening reset cycle.
In the event of an EXB-8200 write failure, or a total system power failure, the
corrective action is to remove and replace the data tape as instructed on the
monitor. This will initiate the automatic re-boot sequence and the system will
return to normal operation.
1. Normal WEEKLY (7 day) reloading sequence.
After seven continuous days of operation, the system will automatically
STOP, EJECT THE TAPE, and CUE the screen.
a. Remove data tape from tape drive.
b. Insert NEW data tape into tape drive.
C. Close the tape drive door.
The system will now automatically stand-by and resume data collection at the
next occurring “TEN MINUTE” data set (in approximately 10 - 20 min.)
2. Abnormal FAULT or POWER LOSS reloading sequence.
If a tape write fault, or a system power interruption occurs, the system will
automatically STOP, EJECT THE TAPE, and CUE the screen. Operator
response is as in the normal WEEKLY sequence.
a. Remove data tape from tape drive.
(Partially filled tapes will NOT be reused.)
b. Insert NEW data tape into tape drive.
C. Close the tape drive door.
....
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was
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 13
cont .... WSI OPERATIONAL CHECKLIST (REF. TABLE A)
The system will now automatically re-boot and proceed through its self test
routine. Upon satisfactory completion of self test the system will automati-
cally STOP, EJECT THE TAPE, and CUE the screen.
a. Close the tape drive door.
The system will now automatically stand-by and resume data collection at the
next occurring “TEN MINUTE” data set (in approximately 10 - 20 min.)
Note that after a FAULT or POWER loss restart as in item 2 above, less than seven
days may remain before the normal WEEKLY reloading day occurs. In this event,
the normal WEEKLY schedule should be re-initiated by operator intervention at the
end of the normally designated 7th day. This re-initiation is most easily accomplished
by inducing a POWER LOSS restart sequence. i.e., Turn off system power momen-
tarily. Turn power back on and proceed as in item 2.
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 14
3.
cont....WSI OPERATIONAL CHECKLISTS (REF. TABLE A)
SOLAR ATTENUATOR ARM REPLACEMENT
The solar attenuator is an equatorially driven device that is designed to prevent
direct solar illumination from falling upon the camera fisheye lens. This
shadowing of the lens prevents undesirable stray light from entering the optical
system and biasing the imagery collected by the camera.
The attenuator is designed to track the sun's position automatically from sunrise
to sunset, and then during the evening hours, reset itself to the next mornings
start position.
There is no automatic adjustment to compensate for the systematic drift that
naturally occurs in solar declination with changes in the season. This necessary
adjustment is accomplished manually by periodically replacing the occultor
support arm.
The required seven support arms, each of slightly different length are provided
by UCSD/MPL as is the Solar Attenuator Arm Change Schedule, See Fig. 6.
Two Attenuator Frame assemblies with glass filters are provided to facilitate
arm changeover procedures.
The arm change procedure is to be accomplished during the evening reset
interval on the dates indicated in Fig. 6.
1. Loosen the three retaining screws on the small external shroud panel,
and remove panel.
2.
Insert 3/32" allen wrench (UCSD/MPL provided) into each of two
10-32 X 3/8" attenuator arm retaining set screws, and loosen each
about one turn.
3.
Lift arm from slotted drive disc.
* 4. Remove square attenuator frame from arm by loosening two 4-40 FH
Nylok attachment screws.
* 5.
Attach square attenuator frame to newly selected attenuator arm.
Assure that arm and frame mate flat-to-flat. Tighten 4-40 screws
securely.
WHOLE SKY IMAGER
(E/O Camera System 5)
Page 15
Insert newly selected attenuator arm into slotted drive disc, and tighten
both 10-32 allen retaining set screws.
Inspect installation for secure attachment of Frame-to-Arm, and Arm-
to-Disc.
* Steps 4 & 5 are accomplished, using alternate Attenuator Frame, in
office environment prior to visiting rooftop camera location.
Weatherproof Lens Housing
Dwg. No. E03-3600-01
Model III Filter Changer
Dwg. No. E03-1200-01
Weatherproof Camera Housing
Dwg. No. E03-3500-01

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Equatorial Drive Assembly
Dwg. No. E03-2102-01
Page 72
Heathkit
OPERATION
OPERATING CHARACTERISTICS
SIGNAL STRENGTH
INITIAL SETTING OF THE CLOCK
The length of time it takes for the GC-1000 Clock
to initially set and update (correct the time) itself
is entirely dependent on how strong the WWV sig-
nals are. The factors which effect the WWV signals
are:
The distance from the WWV transmitter.
The greater the distance, the weaker the
signal strength will be.
The GC-1000 Clock decodes the WWV time codes
(described in the “Theory Of Operation"). This
coded information contains the time, date, UTC cor-
rection factor, and daylight-saving time information.
It takes one minute to decode one complete frame
of data (since that is the rate at which it is sent).
However, due to signal fading conditions, the use
of only one frame of data could cause an erroneous
time to be used to set the clock. To minimize this
possiblilty, the GC-1000 Clock decodes and com-
pares three frames of data. This data must agree be-
fore the time can be set. Once the time is set, the
clock will continue to keep time using its own 3.6
MHz crystal oscillator as a time base.
Weather conditions. When weather condi-
tions are poor, the signals are usually
weaker than normal.
Winter reception is better than summer re-
ception.
When the WWV signal is clear and strong, the clock
will typically set itself in from four to thirty minutes.
Strong WWV signals are characterized by:
•
Loud, clear audible tones.
lonospheric conditions, the time of day, the
season, and sunspot activity. These factors
tend to effect the individual WWV bands.
For example, the best reception generally
occurs on the 5 MHz band at night, 15 MHz
band during the daytime, and the 10 MHz
band near dusk and dawn.
•
Clear voice announcements.
The Capture LED being lit.
Obstacles that block the signals. Moun-
tains, tall buildings, and metal walls are a
few examples.
A flashing Data LED (regular and rhythmic)
each second.
•
A rare WWV band scan.
Other RF signals of sufficient strength to
interfere with good reception.
Some of these factors change and can cause dramatic
differences in signal strength over a time period of
a few minutes to several weeks. However, fixed ob-
stacles and long distances from the transmitter often
dictate the use of an external antenna for accurate
operation of your Clock.
The weaker the WWV signals are, the more the Clock
will deviate from these characteristics and the longer
it will take for the Clock to set itself. NOTE: From
the time you first apply power to your Clock until
it sets itself, you may see "ghosting" of the displays.
This means that the digits will be random and dimly
lit, or they may go out completely. This is normal.
.
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W
Page 73
Heathkit
pe
UPDATING THE CLOCK
often the Clock is updated, the better its accuracy
during periods of the day when the WWV signal is
too weak to be used.
While the Clock is running, it continues to decode
the WWV time code. When the Clock decodes two
frames which agree with the displayed time, the
Clock will update and turn the Hi Spec LED on for
approximately 10 minutes. This updating will cause
the displayed time to be resynchronized to the WWV
time if the error is greater than .005 seconds. Other-
wise, the Clock will automatically adjust (trim) its
3.6 MHz time base oscillator, and cause it to run
even more accurately than before. Thus, the more
Generally, the Hi Spec LED will be lit more than
half the time when WWV reception is strong, and
will be off nearly all the time when WWV reception
is weak. NOTE: If the Clock does not update itself
each day, the . 1 second digit may dim until the Clock
updates, or until ten days have elapsed. If this oc-
curs, it generally means that you need a better an-
tenna system.
FUNCTIONS
Refer to Pictorial 8-1 (Illustration Booklet, Page 13)
for the remaining section.
FRONT WINDOW
mine which channel has the best signal, each
LED alternately illuminates for approximately
3 seconds (while the receiver samples this
channel). When the receiver determines
which channel has the best signal, it will lock
on the signal for approximately 16 seconds,
and the appropriate LED will stay lit to indi-
cate the channel it is monitoring.
.
. .
Display Switch (S101) — The display switch
is located on the left side of the case. When
you slide this switch towards the front of the
case, the LED indicators and 7-digit readouts
are turned on (provided the Clock has set it-
self). When the switch is toward the back of
the case, the indicators and readouts are
turned off to conserve power, (as with 12 VDC
battery operation).
5.
.
.
.
.
.
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.
AM/PM LED Indicators — These indicators
will illuminate only if you select the 12 hr
mode of operation and once the clock has
been set by WWV. They will be out in the
24 hr mode.
Capture LED Indicator - Whenever the re-
ceiver detects the WWV 1000 Hz (800 ms)
tone burst, it will illuminate the capture LED
indicator. If the microprocessor determines
that the WWV information is unclear or mis-
sing, it will then turn off the capture LED and
proceed to the channel that is the clearest and
strongest. If there is no strong signal, it will
scan the channels once more to the highest
frequency for 16 seconds, then repeat the scan
until it finds an acceptable channel. As soon
as another 1000 Hz tone burst is received, the
capture LED will again be illuminated.
6.
Hrs - Mins - Secs LED Indicators — With
the TEST switch (S501) in the NORMal posi-
tion, these digits will be blank (except for the
decimal point) when the clock is initially
powered up, and will stay off until the clock
is set by WWV signals. With the TEST switch
in TEST, the digits and all the LEDs (except
the Data LED) will be lit. The tenths (.1) of
second digit may dim if the Clock does not
update itself each day.
Data LED Indicator – When WWV is being
received, this LED will flash once every sec-
ond (except for the first second of each min-
ute). Each second will vary from short (binary
"O"), to medium (binary "1"), to long (a 10
second marker). NOTE: This flash lags the
seconds update by .2 seconds.
Hi Spec LED Indicator — This LED will il-
luminate for approximately 10 minutes each
time the complete WWV information is re-
ceived and the clock is within 10 mil-
liseconds of the WWV time.

5, 10, 15 MHz LED Indicators - These LEDs
indicate which WWV channel the receiver is
tuned to. While the receiver scans to deter-
will vi mwWwwWwWw
.