PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = " " OBJECT = INSTRUMENT INSTRUMENT_HOST_ID = AMTN INSTRUMENT_ID = CCD OBJECT = INSTRUMENT_INFORMATION INSTRUMENT_NAME = " CHARGE COUPLED DETECTOR" INSTRUMENT_TYPE = "CAMERA" INSTRUMENT_DESC = " " Instrument Overview ================ The data used in this study were collected at the Tortugas Mountain Station of the New Mexico State University Observatory, which is located approximately four kilometers east of Las Cruces, New Mexico at an elevation of 1505 meters (300 meters above the local terrain). The observatory's 61 cm Cassegrain planetary camera was used with a CCD detector illuminated at the f/40 focus. The detector and its support electronics have been loaned to the observatory from the Jet Propulsion Laboratory in Pasadena, California. Scientific Objective =============== The goal of this study was to monitor the episodic nature of convective activity in Jupiter's and Saturn's atmospheres. Instrument Calibration ================= Flat fields were obtained and the data was cleaned and stored along with data of selected reference stars. For detailed calibration at a later date. Operational Considerations ===================== Data was impacted by local observing conditions. Both seeing (the degree of spread of a point source due to small scale atmospheric turbulence) ,excursion of the point source on the detector and transparency of the atmosphere determines the effective resolution of an image. Detectors ========= The detector used was a P8603B manufactured by EEV/GEC, Ltd., one of the earlier versions of CCD's used in astronomical applications. The nominal size of each pixel was about 23 ?m and the entire light sensitive area of the detector consisted of a 385 x 578 array. Only the most defect-free 256 x 256 pixel subsection of the CCD array was retrieved. Filters ======= A wide variety of filters were available for this study. The filters and their spectral characteristics are listed below. The primary filters consisted of a set of narrow-band filters with peak wavelengths centered in and just outside of the three strongest visible/near infrared methane absorption bands. Other filters that were available for this project were duplicates of those filters aboard the Galileo spacecraft. To provide a connection to photographic images taken in the past at the Tortugas Observatory and to the Voyager spacecrafts' blue filter, an additional broad-band blue filter was used (Schott BG-28). FILTER CHARACTERISTICS Wavelength(nm) FWHM (nm) Transmission Notes 450 100 90 1 660 65 90 2 727 18 77 2 755 18 95 2 889 18 79 2 968 Low-Pass 90 2 604 5 71 3 618 2 82 3 727 2 66 3 829 5 63 3 893 12 28 3 Notes: 1. Schott BG-28 from NMSU 2. From Galileo Mission filter set 3. Methane filter set END_OBJECT = INSTRUMENT_INFORMATION OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "Kuehn, 1990" REFERENCE_DESC =" Kuehn, D.M. (1990) A Study of Temporal Behavior of the Vertical Structure of Jupiter's Atmosphere, PhD Dissertation , New Mexico State " END_OBJECT = INSTRUMENT_REFERENCE_INFO END_OBJECT = INSTRUMENT END PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "Lyle Huber, 2008-02-13" OBJECT = DATA_SET DATA_SET_ID = "EAR-J/S-AMTN-2/4-JUP-SAT-MONITORING-V1.0" OBJECT = DATA_SET_INFORMATION DATA_SET_NAME = "Jupiter and Saturn Atmospheric Activity Monitoring - Groundbased" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_OBJECT_TYPE = IMAGE START_TIME = 1988-08-24T10:04:47 STOP_TIME = 1997-06-12T11:48:06 DATA_SET_RELEASE_DATE = 2008-02-15 PRODUCER_FULL_NAME = " David Kuehn and Arthur S Murrell " DETAILED_CATALOG_FLAG = "N" DATA_SET_DESC = " Data Set Overview =========== Jupiter was imaged at high spatial resolution and in several spectral band passes during the period from Aug 1988 to June 1997. In addition, defocused standard stars (See published spectrophotometric standard star data (Taylor, 1984)). were observed at these same wavelengths to allow for the possibility of calculating losses attributable to absorption and scattering processes in the earth's atmosphere. The data used in this study were collected at the Tortugas Mountain Station of the New Mexico State University Observatory, which is located on "A Mountain", approximately four kilometers east of Las Cruces, New Mexico at an elevation of 1505 meters (300 meters above the local terrain). The observatory's 61 cm Cassegrain planetary camera was used with a CCD detector illuminated at the f/40 focus, resulting in a plate scale = 9.381 x 10**-7 rad/pixel. Each image was corrected for the spatially inhomogeneous response of the detector. A portion of this data has been reduced and were included in Kuehn's dissertation (Kuehn, 1990). The data files consist of 256 x256 arrays of unsigned 8 bit integers, scaled as indicated in the headers, with detached labels. The observer's and solar latitudes and longitudes are expressed in planetocentric latitude and System III west longitude. And example of the label content given below. PDS_VERSION_ID          = PDS3   RECORD_TYPE             = FIXED_LENGTH RECORD_BYTES            = 256 FILE_RECORDS            = 256 IMAGE = C0003930.IMG   DATA_SET_ID             = EAR-J/S-AMTN-2/4-JUP-SAT-MONITORING-V1.0 INSTRUMENT_NAME         = EEV/GEC P8603B CCD TARGET_NAME             = JUPITER START_TIME              = 1990-01-08T06:34:44 STOP_TIME               = 1990-01-08T06:34:46   COORDINATE_SYSTEM_CENTER_NAME = PLANET'S CENTER COORDINATE_SYSTEM_ID          = -JUPSYS3 COORDINATE_SYSTEM_NAME        = PLANETOCENTRIC   OBJECT                     = IMAGE   NAME                     = C0003930   LINES                    = 256   LINE_SAMPLES             = 256   SAMPLE_TYPE              = UNSIGNED_INTEGER   SAMPLE_BITS              = 8   EXPOSURE_DURATION        = 2.00    FILTER_NAME              = 604   SUB_SPACECRAFT_LATITUDE  =    2.0   SUB_SPACECRAFT_LONGITUDE =   87.3   SUB_SOLAR_LATITUDE       =    2.0   SUB_SOLAR_LONGITUDE      =   84.8   TARGET_CENTER_DISTANCE   = 6.271E+008   NORTH_AZIMUTH            =  267.2   SCALING_FACTOR           = 2.618E-003 /* I/F = SCALING_FACTOR * DN */   OFFSET                   = 0.0   SLOPE_FILE_NAME          = C0003950.FLT It should be noted that the signal that is measured by the CCD electronics has many sources, only one of which is the signal generated by the photons from the object being observed. Moreover, each pixel is not identical in its sensitivity to light or in its charge transfer efficiency. This leads to an output image that may have pixels or entire columns that are nonresponsive to light. The various contributions to the measured signal can be written in the following form for each row and column: Crc = Rrc*Src + Drc + Trc where for each pixel Crc = measured signal, Rrc = linear response coefficient, Drc = dark readout noise, Trc = thermal noise, and Src = actual signal, r, c = row and column of each pixel. In the case of short exposures, the thermal noise contribution is negligible because the CCD is cooled with liquid nitrogen to 135 K and there isn't enough time for charge to build up. This additive term was ignored. Several dark frames were read out in rapid succession and added. It was found that when only the most significant eight bits of the intensity information were stored, the readout noise of the CCD was not measurable. Therefore, the dark frame component was ignored. The remaining term is due to interpixel differences in the response to light. This results from irregularly sized electrodes and is fixed with time. Additional sources of nonuniform response across the CCD are due to filter inhomogeneities and dust present near the focal plane of the telescope. These effects are not constant with wavelength. To compensate for the nonuniform response, the telescope's optics were trained on a uniformly illuminated white screen on the inside of the observatory dome. Images were taken of this "flat field" of view through each of the filters on every night of observation. The flat field images were divided (pixel by pixel) into each image of the target objects (e.g., Jupiter and the calibration stars). This operation then leaves only the signal Src remaining. Following this operation, the detector's nonresponsive pixels and columns were corrected by interpolation on neighboring pixels or columns. In summary: Each image has been corrected for interpixel differences by dividing them by flat-field images. The image scale was found by imaging stars with calibrated separations. The orientation of the camera on the sky was determined by imaging star trails. The center of each image of Jupiter was found through limb fitting and An ephemeris was used to derive the corresponding viewing geometry. " END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = JUPITER END_OBJECT = DATA_SET_TARGET END_OBJECT = DATA_SET END OBJECT = DATA_SET_REFERENCE_INFO REFERENCE_KEY_ID = "Taylor, B.J. (1984) An Augmented system of Secondary Standards for Bright-Star Spectrophotometry, Ap. J. Suppl.54" END_OBJECT = DATA_SET_REFERENCE_INFO OBJECT = = DATA_SET_REFERENCE_INFO REFERENCE_KEY_ID = "Kuehn, 1990" REFERENCE_DESC =" Kuehn, D.M. (1990) A Study of Temporal Behavior of the Vertical Structure of Jupiter's Atmosphere, PhD Dissertation , New Mexico State " END_OBJECT = = DATA_SET_REFERENCE_INFO END_OBJECT = INSTRUMENT END The data has been cleaned and, although the headers have not yet been converted to PDS labels, the xxx.HDR files are human readable and this version can be browsed to look for episodic recurrences of Jovian phenomena. A catalogue will be added as time permits. The data consist of 256 x256 arrays of unsigned 8 bit integers, scaled as indicated in the headers, with detached labels. The observer's and solar latitudes and longitudes are expressed in Planetocentric Latitude and System III West Longitude. And example of the label content is given below. PDS_VERSION_ID          = PDS3   RECORD_TYPE             = FIXED_LENGTH RECORD_BYTES            = 256 FILE_RECORDS            = 256 File Name = C0003930.IMG   DATA_SET_ID             = EAR-J/S-AMTN-2/4-JUP-SAT-MONITORING-V1.0 INSTRUMENT_NAME         = EEV/GEC P8603B CCD TARGET_NAME             = JUPITER START_TIME              = 1990-01-08T06:34:44 STOP_TIME               = 1990-01-08T06:34:46   COORDINATE_SYSTEM_CENTER_NAME = PLANET'S CENTER COORDINATE_SYSTEM_ID          = -JUPSYS3 COORDINATE_SYSTEM_NAME        = PLANETOCENTRIC   OBJECT                     = IMAGE   NAME                     = C0003930   LINES                    = 256   LINE_SAMPLES             = 256   SAMPLE_TYPE              = UNSIGNED_INTEGER   SAMPLE_BITS              = 8   EXPOSURE_DURATION        = 2.00    FILTER_NAME              = 604   SUB_SPACECRAFT_LATITUDE  =    2.0   SUB_SPACECRAFT_LONGITUDE =   87.3   SUB_SOLAR_LATITUDE       =    2.0   SUB_SOLAR_LONGITUDE      =   84.8   TARGET_CENTER_DISTANCE   = 6.271E+008   NORTH_AZIMUTH            =  267.2   SCALING_FACTOR           = 2.618E-003 /* I/F = SCALING_FACTOR * DN */   OFFSET                   = 0.0   SLOPE_FILE_NAME          = C0003950.FLT The data has been cleaned and this version can be browsed to look for episodic recurrences of Jovian phenomena. It should be noted that the signal that is measured by the CCD electronics has many sources, only one of which is the signal generated by the photons from the object being observed. Moreover, each pixel is not identical in its sensitivity to light or in its charge transfer efficiency. This leads to an output image that may have pixels or entire columns that are nonresponsive to light. The various contributions to the measured signal can be written in the following form for each row and column: Crc = Rrc*Src + Drc + Trc where for each pixel Crc = measured signal, Rrc = linear response coefficient, Drc = dark readout noise, Trc = thermal noise, and Src = actual signal, r, c = row and column of each pixel. In the case of short exposures, the thermal noise contribution is negligible because the CCD is cooled with liquid nitrogen to 135 K and there isn't enough time for charge to build up. This additive term was ignored. Several dark frames were read out in rapid succession and added. It was found that when only the most significant eight bits of the intensity information were stored, the readout noise of the CCD was not measurable. Therefore, the dark frame component was ignored. The remaining term is due to interpixel differences in the response to light. This results from irregularly sized electrodes and is fixed with time. Additional sources of nonuniform response across the CCD are due to filter inhomogeneities and dust present near the focal plane of the telescope. These effects are not constant with wavelength. To compensate for the nonuniform response, the telescope's optics were trained on a uniformly illuminated white screen on the inside of the observatory dome. Images were taken of this "flat field" of view through each of the filters on every night of observation. The flat field images were divided (pixel by pixel) into each image of the target objects (e.g., Jupiter and the calibration stars). This operation then leaves only the signal Src remaining. Following this operation, the detector's nonresponsive pixels and columns were corrected by interpolation on neighboring pixels or columns. In summary, each image has been corrected for interpixel differences by dividing them by flat-field images. The image scale was found by imaging stars with calibrated separations. The orientation of the camera on the sky was determined by imaging star trails. The center of each image of Jupiter was found through limb fitting and an ephemeris was used to derive the corresponding viewing geometry. " END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = JUPITER END_OBJECT = DATA_SET_TARGET END_OBJECT = DATA_SET END OBJECT = DATA_SET_REFERENCE_INFO REFERENCE_KEY_ID = "Taylor, B.J. (1984) An Augmented system of Secondary Standards for Bright-Star Spectrophotometry, Ap. J. Suppl.54" REFERENCE_DESC ="Hapke, Bruce (1981) Surface Reflectance, Jour. Of Geophysical Research, Vol 86, p3039-3054" END_OBJECT = DATA_SET_REFERENCE_INFO OBJECT = = DATA_SET_REFERENCE_INFO REFERENCE_KEY_ID = "Kuehn, 1990" REFERENCE_DESC =" Kuehn, D.M. (1990) A Study of Temporal Behavior of the Vertical Structure of Jupiter's Atmosphere, PhD Dissertation , New Mexico State " END_OBJECT = = DATA_SET_REFERENCE_INFO END_OBJECT = INSTRUMENT END