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1"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Metrics((
Peter(Yoachim(University(of(Washington(
(Cadence(Workshop(August(11=15,(2014(
2"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
LSST"Era"Astronomy"
− Over"10"years,"LSST"will"make"around"2.5"million"visits"
− Need"a"tool"to"analyze"~300"log"books"
3"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
The"OperaNons"Simulator"(OpSim)"and"Metrics"Analysis"Framework"(MAF)"
− OpSim"generates"realisNc"10;year"LSST"poinNng"histories"
– 2.5"million"visits"
– For"each"visit,"record"Nme,"airmass,"ra,"dec,"seeing,"sky"brightness,"filter,"etc."
− MAF"provides"a"framework"for"visualizing"and"analyzing"the"
scienNfic"usefulness"of"a"survey"
4"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Simple"Metrics"
− Combine:"
– Single"columns"from"OpSim"like:"
airmass,"seeing,"sky"brightness"
– Simple"algorithms"like:"Mean,"Median,"Coadded"depth,"RMS,"etc"
5"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Median"Airmass"
6"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Max"Airmass"
7"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Median"Sky"Brightness"
8"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Coadded"depth"
9"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Number"of"Visits"
10"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Just"a"reminder"that"all"these"maps"come"with"histograms"and"power"spectra"
11"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Single"Visit"Depths"
12"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
New"Cadence"Metrics"
− Astrometry"
− Supernova"− Availability"of"templates"
− Uniformity"
13"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Proper"MoNon"Metric"
Time"
PosiNon"
Error"bar"determined"by"seeing,"image"depth,"
systemaNc"limit"
If"there"are"no"degeneracies"in"the"astrometric"fit,"the"uncertainty"in"the"proper"moNon"is"a"funcNon"of"
the"measurement"uncertainNes"and"the"observaNon"Nmes."
σ1"="FWHM/SNR"σ2"="0.01"arcsec"
14"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Proper"MoNon"Precision"
Assuming"a"20th"mag,"flat"SED"star"and"a"systemaNc"centroiding"limit"of"10"mas"
beDer( worse(
15"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Compare"to"an"“opNmized”"survey"PosiNon"
PosiNon"
Compare"the"observed"precision"to"the"
precision"obtained"by"moving"all"the"
observaNons"to"1st"and"last"day."""
16"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Proper"MoNon"RelaNve"to"“opNmal”"
More(OpGmized(
Less(OpGmized(
17"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Parallax"
PosiNon"
Again,"assume"a"20th"mag"flat"SED"star.""No"proper"moNon"or"degeneracies"in"the"parallax"fit"(not"true"for"1st"6"months"at"least!)"
RA"and"Dec"parallax"precision"calculated"independently,"then"combined."
Time"
18"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Parallax"Precision"
beDer( worse(
19"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Compare"to"an"opNmized"parallax"survey"PosiNon"
PosiNon"
Compare"to"a"survey"where"all"observaNons"are"taken"at"
maximum"parallax"factor"
20"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Parallax"Precision"compared"to"“opNmized”"
90"degrees"away"from"eclipNc,"scheduling"doesn’t"majer"much"(always"at"full"parallax"amplitude).""On"eclipNc,"
scheduling"important"
More(OpGmized(
Less(OpGmized(
21"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Blink"for"fun"
22"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
“opNmized”"
PosiNon"
PosiNon"
Note"that"the"“opNmized”"
comparison"only"moves"observaNons"in"
Nme,"and"does"not"consider"things"like"
filter"distribuNon,"
moon"phase,"etc."
23"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Temporal"Uniformity"
CumulaNve"DistribuNon"FuncNon"
Time" 10"years"0"
uniform"
Observed"
Dmax"
0"
100%"
24"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Temporal"Uniformity"
Value"of"zero"is"perfectly"uniform,"value"of"1"would"mean"all"the"observaNons"were"taken"on"a"single"day."
More"uniform" Less"uniform"
25"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
FracNon"of"ObservaNons"with"Good"Templates"
For"image"differencing,"we"need"a"pre;exisNng"image"taken"in"similar"or"bejer"seeing."
26"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Supernova"Metric"
− Say"a"SN"goes"off"every"5"days."− Check"if"the"SN"is"“well"observed”"(criteria"from"Science"Book)"
– ObservaNons"in"least"2"filters"near"peak"– Max"gap"of"15"days"near"peak"
– At"least"1"early"observaNon"– At"least"1"late"observaNon"– At"least"7"total"observaNons"– Only"use"filters"between"300"and"900"nm"in"SN"resnrame"
– Signal"to"noise"criteria"(not"implemented)"
27"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
SN"Light"Curve"
≥2"observaNons"≥2"filters"No"gap"of">15"days"
≥1"obs"
≥1"obs"
≥7"observaNons"
+Only"resnrame"opNcal"filters"
28"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
That’s"a"lot"of"if;statements"
for i,index in enumerate(ind): if i <= right_side: pass else: visits = dataSlice[left[i]:right[i]] t = time[left[i]:right[i]] t = t-finetime[index]+self.Tmin if np.size(np.where(t < self.Tless)[0]) > self.Nless: if np.size(np.where(t > self.Tmore)[0]) > self.Nmore: if np.size(t) > self.Nbetween: ufilters = np.unique(visits[self.filterCol]) if np.size(ufilters) >= self.Nfilt: #XXX need to add snr cut here filtersBrightEnough = 0 nearPeak = np.where((t > self.Tless) & (t < self.Tmore)) ufilters = np.unique(visits[self.filterCol][nearPeak]) for f in ufilters: if np.max(visits[self.m5Col][nearPeak] [np.where(visits[self.filterCol][nearPeak] == f)]) \ > self.singleDepthLimit: filtersBrightEnough += 1 if filtersBrightEnough >= self.Nfilt: if np.size(nearPeak) >= 2: gaps = t[nearPeak][1:]-np.roll(t[nearPeak],1)[1:] else: gaps = self.peakGap+1e6 if np.max(gaps) < self.peakGap: result += 1 if self.uniqueBlocks: right_side = right[i] maxGap.append(np.max(gaps)) Nobs.append(np.size(t))"
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29"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Supernova"Light"Curve"Sampling"
A"new"z=0"SN"goes"off"every"5"days"at"each"healpixel.""How"many"are"“well"observed”?""(max"possible"~700,"we"get"200;300"in"the"WFD"area)"
30"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Supernova"
For"those"well"sampled"SN,"the"median"number"of"observaNons"per"light"curve."
31"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
For"well"sampled"SN,"the"median"gap"in"days"near"maximum"light."(max"possible"is"15)"
All"of"these"maps"also"include"histograms,"power"
spectra,"and"any"summary"stats."
32"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Conclusions"
− We"have"lots"of"metrics"
− We’d"like"more"
33"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Solar"System"
TBD"
34"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"
Gaps"in"Observing"
35"LSST"Cadence"Workshop"•"Phoenix"•"August"11;15,"2014"