urn:nasa:pds:uranus_occ_u102a_irtf_320cm:data:2200nm_counts-v-time_rings_egress
1.0
Uranus Ring Egress Occultation of Star u102a (UCAC2 22794648) Observed from the IRTF 320cm Telescope
1.14.0.0
Product_Observational
French, Richard G.; McGhee-French, Colleen A.; Gordon, Mitchell K.
2020
uranus rings
uranus rings stellar occultation
uranus rings stellar occultation radial profile
Derived normalized signal vs. time from the egress ring occultation of star u102a (UCAC2 22794648) observed by the IRTF 320cm Telescope.
2021-04-05
1.0
Initial version
1992-07-08T10:31:17.1850Z
1992-07-08T10:57:21.4950Z
Science
Calibrated
This is the time series (normalized stellar flux vs. time) for the occultation of star u102a (UCAC2 22794648) by the rings of Uranus.
Infrared
Ring-Moon Systems
Ring Occultation Profile
Earth-based Observations of Uranus System Stellar Occultations
Observing Campaign
urn:nasa:pds:context:investigation:observing_campaign.earth-based-uranus-stellar-occultations
data_to_investigation
IRTF 320cm Telescope
Infra Red Telescope Facility-Maunakea
Host
urn:nasa:pds:context:facility:observatory.irtf-maunakea
is_facility
IRTF 3.2m
Telescope
urn:nasa:pds:context:telescope:irtf-maunakea.3m2
is_telescope
Generic InSb High Speed Photometer
Instrument
urn:nasa:pds:context:instrument:multi-host.generic_insp_hsp
is_instrument
Uranus Rings
Uranian Ring System
Ring
urn:nasa:pds:context:target:ring.uranus.rings
data_to_target
SPK
ura111.bsp
SPK
vgr2.ura111.bsp
SPK
earthstns_itrf93_040916.bsp
BPC
earth_720101_031229.bpc
LSK
naif0012.tls
These kernel files were used in the generation of the products in the parent bundle. Some or all of them may not have been used directly in the generation of this product.
stellar
both
egress
Y
poor
equator
UCAC2 22794648
1.75
0.5500
0.1500
0.020000000
double pole
0.12500
0.02500
1903.00000
2416.00000
1992-07-08T00:00:00.0000Z
37877.1850
39441.4950
-236136463.6311
-236134899.3211
1992-07-08T10:31:17.1850Z
1992-07-08T10:57:21.4950Z
30000.13214
69999.80750
165.7073
177.0143
145.8767
157.1837
-60.47479
29.52521
urn:nasa:pds:uranus_occ_support:document:earth-based-uranus-stellar-occultations-user-guide
data_to_document
The Users Guide for all of the Earth-based Uranus system occultations.
urn:nasa:pds:uranus_occ_u102a_irtf_320cm:data:2200nm_counts-v-time_occult
data_to_calibrated_product
Normalized counts vs. time for the entire occcultion.
urn:nasa:pds:uranus_occ_u102a_irtf_320cm:browse:2200nm_obs_geom
data_to_browse
Diagram of the Uranus system showing the occultation track.
urn:nasa:pds:uranus_occ_u102a_irtf_320cm:browse:2200nm_earth
data_to_browse
Diagram of the view of the Earth from Uranus at mid-occultation Time.
urn:nasa:pds:uranus_occ_u102a_irtf_320cm:browse:2200nm_alt
data_to_browse
Plot of the altitude (in degrees) of Uranus and the sun relative to the horizon over the duration of the occulation.
urn:nasa:pds:uranus_occ_u102a_irtf_320cm:browse:2200nm_counts-v-time_rings_egress
data_to_browse
Low resolution plot of the egress counts vs. time for the ring occcultion.
urn:nasa:pds:uranus_occ_u102a_irtf_320cm:browse:2200nm_counts-v-time_normalization
data_to_browse
Illustrates some of the processing steps involved in normalizing a time-series occultation light curve from counts per second to units of stellar flux.
urn:nasa:pds:uranus_occ_support
data_to_resource
The support bundle for all of the Earth-based Uranus system occultations.
urn:nasa:pds:uranus_occ_support:data:uranus_occultation_ring_fit_rfrench_20201201::1.0
data_to_resource
The fitted model of the ring system upon which the data are based.
u102a_irtf_320cm_2200nm_counts-v-time_rings_egress.tab
ring-data
2021-04-05T14:38:26Z
0
264
UTF-8 Text
Provides the column headers, separated by commas, for the data table.
264
156432
This is a calibrated time series of an occultation by the rings of Uranus
generated from an earth-based stellar occultation. The data are uniformly spaced in time,
normalized in units of stellar intensity, and include the equatorial ring plane radius
sampled at each time point, computed from an orbit model for the ring system.
Carriage-Return Line-Feed
15
0
212
Observed Event Time
1
1
ASCII_Real
16
second
The instant at which photons were received at the observer location. It is
represented in the Universal Coordinated Time system, as a number of elapsed
seconds since the time given by the reference_time_utc attribute specified in this file.
It refers to the middle of the bin.
Observed Event TDB
2
19
ASCII_Real
16
second
The instant at which photons were received at the observer location. It is represented
in the 'Barycentric Dynamical Time' system, as a number of elapsed seconds since the J2000 epoch.
Mean Signal
3
37
ASCII_Real
16
Mean counts received by the instrument during this time bin. The background
signal has not been subtracted. Refer to NOTE FLAG for guidance on validity of data.
999999999.999999
999999999.999999
Normalized Signal
4
55
ASCII_Real
10
Normalized signal during this time bin, in units of the unocculted stellar signal,
such that 1.0 corresponds to the full unocculted star signal and
0.0 corresponds to no counts from the star (a completely opaque ring).
NORMALIZED SIGNAL = (MEAN_SIGNAL - BACKGROUND_MODEL)/(UNOCCULTED STAR MODEL)
This is an approximate normalization, computed using regional polynomial fits.
For high-precision photometry of ring events, use locally computed normalization.
999.999999
999.999999
Sky-plane F
5
67
ASCII_Real
13
Kilometer
The east/west component of r sky (positive in the east direction), in km.
Sky-plane G
6
82
ASCII_Real
13
Kilometer
The north/south component of r sky (positive in the north direction), in km.
Sky-plane Radius
7
97
ASCII_Real
13
Kilometer
The length of the radius vector in the plane of the sky measured from the center of the occulting object to the position of the occulted star or spacecraft, in km.
Ring Radius
8
112
ASCII_Real
12
Kilometer
Radial distance of the occultation intercept point (middle of the bin) from
the center of the planet, in km. Distances are measured along the equator plane.
Ring Longitude
9
126
ASCII_Real
8
Degree
Inertial longitude on the ring plane corresponding to the midpoint of the bin.
Observed Ring Azimuth
10
136
ASCII_Real
9
Degree
Angle measured at a point in the ring plane, starting from the direction of
a photon heading to the observer, and ending at the direction of a local radial vector.
This angle is projected into the ring plane and measured in the prograde direction.
Ring Event TDB
11
147
ASCII_Real
16
second
The time at which photons left the ring plane. This time is earlier than the associated
OBSERVED EVENT TDB by an amount equal to the light travel time. It is represented in the
'Barycentric Dynamical Time' system, as a number of elapsed seconds since the J2000 epoch.
Unocculted Star Model
12
165
ASCII_Real
16
Model of the unocculted star signal as a function of ring plane radius. This is necessary
because of variations in atmospheric transparency and other time-dependent effects.
999999999.999999
999999999.999999
Background Model
13
183
ASCII_Real
16
Model of the non-stellar background signal (which may vary over the course of the
occultation) due to instrumental offsets applied during the recording and/or sky brightness
and contributions from reflected sunlight from the rings and planet.
999999999.999999
999999999.999999
Number Of Samples Per Bin
14
201
ASCII_Integer
4
The number of raw data points per bin.
Note Flag
15
207
ASCII_Integer
4
A numerical flag that associates
specific comments with individual data bins. When more than one
comment applies, the values are summed. The values and their
associated comments are:
0: radius and longitude are based on Uranus equatorial plane.
1: radius and longitude are based inclined ring plane model
referred to in metadata associated with file.
2: observed ring occultation event
4: telescope pointed to nearby sky for background level check
8: input signal from time source, not from photometer on telescope
16: line of sight intersects planet
32: dawn/dusk - rapid background level change;
no background or star intensity estimate.
64: unreliable data (e.g., clouds, telescope
guiding error, or instrument adjustment);
no background or star intensity estimate.