GlSch: Obse a ion Schedule o he GLORIA Telescope
Ne wo k
Ca men L´opez-Casadoa, Ca los J. P´e ez del Pulga a, V´ıc o F. Mu˜noza, and Albe o
Cas o-Ti adob
aDepa amen o de Ingenie a de Sis emas y Au om ica, Uni e sidad de Mlaga. Campus de
Excelencia In e nacional Andaluca Tech.
bDepa amen o de Fsica Es ela , Ins i u o de As o sica de Andaluca,
ABSTRACT
This pape p oposes he design and de elopmen o a schedule o he GLORIA elescope ne wo k. This ne wo k,
which main objec i e is o make as onomy close o ci izens in gene al, is o med by 18 elescopes sp ead o e
ou con inen s and bo h hemisphe es. Pa o he managemen o his ne wo k is made by he ne wo k schedule .
I ecei es he obse a ion eques s made by he GLORIA use s and hen sends i o he mos sui able elescope.
A key module o he ne wo k schedule is he elescope decision algo i hm ha makes possible o choose he bes
elescope, and hus a oiding o e ing an obse a ion o a elescope ha canno execu e i . This pape shows wo
di e en elescope decision algo i hms: he i s one is only based on wea he o ecas , meanwhile he second one
uses uzzy logic and in o ma ion om each ne wo k elescope. Bo h algo i hms we e deployed in he GLORIA
ne wo k. The achie ed esul s coupled wi h a compa a i e o hei pe o mance is shown. Mo eo e , he ne wo k
schedule a chi ec u e, based on a hyb id dis ibu ed-cen alized schema, is de ailed.
Keywo ds: As onomy, elescope ne wo k, schedule algo i hm, uzzy logic, so wa e
1. INTRODUCTION
O e he las decades, he e has been an inc ease in elescope ne wo k implemen a ions. The e is a huge
in e es in making as onomy close o s uden s and ci izens in gene al [1,2]; p o iding easy- o-use web ools o
awake hei in e es . On he o he hand, elescope ne wo ks ocused on p o essional as onome s ha e also been
de eloped [3,4].
Main pa o hese ne wo ks is based on a coo dina o o schedule ha manages all he eques s. These
eques s will include in o ma ion abou he a ge o obse e and also how o obse e i , i.e. he cons ain s.
Depending on his da a, he schedule will p opose he obse a ion o a speci ic elescope and a e wa ds, i will
execu e he obse a ion i sel . The design and implemen a ion o he schedule in he ne wo k can be dis ibu ed
o ully cen alized. The dis ibu ed a chi ec u e [5] usually includes a cen al node ha decide he elescope
and local nodes ha schedule all he ecei ed obse a ions. On he o he hand, cen alized sys ems [6] schedule
all he elescope obse a ions in he cen al node. The elescope only ac s as a sequence , ecei ing ins uc ions
and gene a ing da a.
In he las e m o 2014, he GLORIA ne wo k [1] was launched wi h he aim o c ea e a wo ld-wide elescope
ne wo k whe e use s could esea ch in as onomy using obo ic elescopes, and/o analyzing da a which o he
use s ha e acqui ed. I in eg a es elescopes ha ha e been wo king in a ious scien i ic ields and dissemina ion
issues, c ea ing a he e ogeneous elescope ne wo k. As a pa o his ne wo k, a schedule has been designed
and i is being implemen ed and deployed. This schedule manages all he obse a ion eques s and decide he
elescope ha will be o e ed he obse a ion. This decision is made h ough a elescope decision algo i hm.
This pape de ails he GLORIA ne wo k in sec ion 2, as well as he a chi ec u e o he schedule in sec ion
3. The di e en elescope decision algo i hms a e explained in sec ion 4. Nex , he s a is ic esul s o e he
ne wo k usage a e shown in sec ion 5. Finally, conclusions a e in sec ion 6.
2. THE GLORIA TELESCOPE NETWORK
The GLORIA ne wo k in eg a es 18 elescopes wo ldwide (Figu e 1) ha had been wo king in a ious scien i ic
ields and dissemina ion issues, c ea ing a he e ogeneous ne wo k whe e elescopes ime is sha ed be ween owne s
and he GLORIA ne wo k.
Figu e 1. Geog aphic loca ion o he GLORIA elescopes.
The unde lying idea in GLORIA is ha he mo e eyes we would pu on he sky he mo e and g ea e he
scien i ic disco e ies ha will be achie ed. Taking ad an age o collec i e in elligence [7] he huge amoun o
as onomical da a can be analyzed by bo h p o essional and ama eu as onome s. Thus, in o de o y o
imp o e he way o doing as onomy esea ch, use s will be guided h ough he di e en asks he esea ch
equi es. Each kind o esea ch has been called expe imen . The e a e wo kinds o expe imen s: hose ha
equi e a elescope, which ha e been called on-line expe imen s and o -line expe imen s which wo k on da a
p oduced by he GLORIA ne wo k. The a ailable o -line expe imen s a e: Pe sonal Space, whe e you choose an
impo an e en in you li e and see he sky ha was di ec ly o e head a ha exac momen ; o Sola Ac i i y,
whe e you can con ibu e o he measu emen o sola ac i i y; and Va iable S a s ha allows he analysis o
he ligh cu es o he s a s.
On he o he side, on-line expe imen s a e also di ided in o wo ca ego ies: eleope a ion and ba ch. The
i s one is used o di ec ly con ol he elescope a a speci ic da e and ime, which is chosen by he use . A ha
da e, use will be able o con ol he elescope moun o poin a a speci ic a ge , selec he il e , ocus and se
he exposu e ime o ake an image ha can be inally downloaded. On he o he hand, in ba ch mode, use s do
no con ol he elescope; ins ead, a eques o obse e a a ge is submi ed o he ne wo k and he schedule
will manage he obse a ions.
3. GLSCH: OBSERVATION SCHEDULER
Mos o he elescope ne wo ks ha a e cu en ly in use o ha a e being de eloped ha e a common cha ac e is ic:
hei elescopes a e only used by he ne wo k and hey ha e he same con ol sys em. Howe e , one o he key
ac o s o he GLORIA ne wo k is ha he elescope usage in he ne wo k is sha ed wi h he elescope owne ; he
idea is o o e , a leas , he elescope idle ime o he GLORIA communi y. This p i a e and public coexis ence
make manda o y he use o he elescope own con ol sys em and he local schedule p o ided wi h i . This ac
makes he GLORIA ne wo k o be he e ogeneous no only because i s elescopes ha e di e en ea u es, bu also
because he e a e di e en con ol sys ems o manage hem (RTS2 [8], ACP [9] ...). Mo eo e , o combine he
exis ence o a ne wo k schedule o manage he en i e use eques s, and also keep he elescope au onomy, he
elescope local schedule has o belong o he GLORIA schedule a chi ec u e.
The GLORIA schedule manages all he use eques s, aking in o accoun he cons ain s o be sa is ied and
deciding o which elescope he obse a ion will be o e ed. Then, he own elescope schedule will include he
obse a ion wi hin he nigh plan which has o be execu ed. The igu e 2shows he schedule hyb id dis ibu ed-
cen alised a chi ec u e. I is based on 3 laye s: he uppe one o med by a unique node he Cen al Node. The
middle laye whe e he e is a Local Node o each elescope in he ne wo k and inally he lowe laye whe e he
elescopes hemsel es a e loca ed.
Figu e 2. GlSch a chi ec u e.
3.1 Obse a ion managemen p ocess
The i s s ep o he obse a ion managemen p ocess is made by he Cen al Node, once he use has submi ed
he obse a ion i has o assu e ha he eques is complian wi h he eques schema. Then a cons ain
analysis is made. The cons ain s a e di ided in o ime cons ain s, ha d cons ain s and isibili y cons ain s.
The analysis o he i s wo ones is made by he Cen al Node. Time cons ain s de ine a ime window whe e he
obse a ion has o be pe o med. I his window is wi hin he ma gins he schedule is p ocessing, he eques
analysis will con inue; i no , i will be schedule la e . Nex cons ain s o be checked a e he ha d ones; hese
a e cons an o can be conside ed as cons an om he poin o iew o he elescope/obse a o y. The isibili y
cons ain s depend on he exac ime he a ge will be obse ed, e.g. a ge al i ude. The Cen al Node will
communica e wi h he local nodes o p o ide hem all he in o ma ion needed o make a isibili y s udy and
decide i he a ge can be obse ed o no . Finally, he Cen al Node, h ough he decision algo i hm, will
choose he elescope ha will be o e ed he obse a ion.
The Local Node, associa ed o he chosen elescope, no i ies he obse a ion o he elescope local schedule .
The ways o submi ing a new obse a ion o he hi d-pa y schedule s includes om c ea ing and uploading a
new ile (ACP) o use an speci ic in e ace o c ea e and hen schedule a a ge (RTS2, some cus om sys ems).
Then he elescope schedule manages he obse a ion including i in o i s nigh plan. The esul o his p ocess
can be posi i e when he obse a ion images ha e been aken; o nega i e, when he obse a ion has no been
execu ed. I local elescope schedule comple es he obse a ion, he local node e ches he images and a no i-
ica ion is sen o he cen al node which upda es he eques s a e. On he o he hand, when no images ha e
been aken, a ealloca ion p ocess, o choose ano he elescope, is s a ed.
4. TELESCOPE DECISION ALGORITHM
The di e ence in he a chi ec u e and usage o he ne wo k makes he schedule main goal o be also di e en .
While minimizing he ime pe obse a ion is he main objec i e in mos o he elescope ne wo k, he p incipal
GLORIA objec i e is o maximize he numbe o comple ed obse a ions. As each GLORIA elescope has i s
own con ol sys em wi h i s own local schedule , he obse a ion ime canno be con olled. Each GLORIA
eques will be included in he elescope nigh plan and GLORIA does no ha e any con ol abou he execu ion
ime slo . To a oid o e ing an obse a ion o a elescope ha canno execu e i and hen making he o e all
p ocess longe , he elescope decision algo i hm is c ucial.
Nex , he wo elescope decision algo i hm ha has been designed and implemen ed a e explained.
(a) Accep ance Ra e (b) Realloca ion s eps
Figu e 3. Algo i hm pe o mance compa a i e
4.1 Wea he o ecas algo i hm
This elescope decision algo i hm is based on wea he o ecas . This in o ma ion has been aken om 7 ime [10],
a ee p ojec ha p o ides speci ic in o ma ion o as onomy. The elescope decision algo i hm ecei es he
wea he o ecas o e e y elescope ha passed he cons ain s. Fo each o hem, a sco e is compu ed aking
in o accoun he wea he condi ion in i s nigh hou s, he pa ame e s conside ed a e he wea he o ecas (cloud
co e and p ecipi a ion ype) and he seeing.
4.2 Fuzzy logic algo i hm
This elescope decision algo i hm uses a uzzy logic model o sco e each a ailable elescope. The uzzy model uses
di e en kind o inpu pa ame e s: as onomical wea he in o ma ion, a ge quali y obse a ion and elescope
ne wo k eedback.
The as onomical wea he pa ame e s in o ms abou he wea he condi ion a he obse a o y loca ion:
wea he o ecas and seeing as hey we e used in he wea he o ecas algo i hm. The pa ame e used o measu e
he a ge quali y a he obse a o y loca ion is he Ta ge T ansi Al i ude. Finally, he e a e wo elescope
ne wo k eedback pa ame e s o include in o ma ion abou he p e ious pe o mance o he elescopes. The
Use Sco e, once an obse a ion is comple ed, GLORIA use s sco e he image aken by he elescope. And he
Telescope Accep ance Ra e, he pe cen age o execu ed obse a ions o e he o al o e ed ones.
5. RESULTS
The schedule ha has been desc ibed coupled wi h he de ailed decision algo i hms we e deployed and es ed
in o he GLORIA ne wo k. The expe imen consis ed o analyzing he in o ma ion p oduced by he ne wo k
du ing wo pe iods. In he i s one, he wea he o ecas algo i hm was used, meanwhile in he second pe iod
he uzzy logic one was ac i e.
Figu e 3a e eals ha he accep ance a e o bo h ype o algo i hm a e qui e simila : 37,96% when he
wea he o ecas algo i hm was in used and 43,58% when he uzzy logic one was ac i e. Howe e , a deepe
analysis on comple ed obse a ion (Figu e 3b), speci ically in he numbe o ealloca ion s eps, shows ha when
uzzy logic algo i hm is used he 77% o he comple ed obse a ion we e made by he i s elescope he algo i hm
chose e sus he 56% associa ed o he wea he based algo i hm. Tha means ha he o e all obse a ion ime
we e educe when using he uzzy logic algo i hm, exac ly i was mo ed om 41 hou s o less ha 28.
6. CONCLUSIONS
This pape has desc ibed he hyb id dis ibu ed-cen alised a chi ec u e o he GLORIA schedule , as well as
he wo di e en elescope decision algo i hms ha has been implemen ed and es ed in he GLORIA ne wo k.
A compa a i e be ween bo h algo i hms has been made and shows ha he uzzy logic algo i hm educes he
ealloca ion p ocess and hus he o e all ime o comple e he obse a ion.
ACKNOWLEDGMENTS
This wo k has been pa ially suppo ed by he GLORIA p ojec . GLObal Robo ic elescopes In elligen A ay
o e-Science (GLORIA) is a p ojec unded by he Eu opean Union Se en h F amewo k P og amme (FP7/2007-
2012) unde g an ag eemen numbe 283783.
REFERENCES
[1] Cas o-Ti ado, A. J., S´anchez Mo eno, F. M., P´e ez del Pulga , C., Az´oca , D., Beskin, G., Cabello,
J., Cedazo, R., Cues a, L., Cunni e, R., Gonz´alez, E., Gonz´alez-Rod ´ıguez, A., Go osabel, J., Hanlon,
L., Hudec, R., Jakubek, M., Janecek, P., Jel´ınek, M., La a-Gil, O., Lin o , C., L´opez-Casado, M. C.,
Malaspina, M., Mankiewicz, L., Mau ei a, E.; Maza, J., Mu˜noz-Ma ´ınez, V. F., Nicas o, L., OBoyle, E.,
Palazzi, E., P´a a, P., Pio, M. A., P ouza, M., Se ena, F., Se a-Rica , M., Simpson, R., Sp imon , P.,
S obl, J., Topinka, M., Vi ek, S., and Za necki, A. F., “The GLObal Robo ic elescopes In elligen A ay
o E-Science (GLORIA),” Re is a Mexicana de As onom´ıa y As o ´ısica 45, 104–109 (2014).
[2] G esham, K. C., Palma, C., Polsg o e, D. E., Chun, F. K., Della-Rose, D. J., and Tippe s, R. D., “Educa ion
and ou each using he alcon elescope ne wo k,” Ac a As onau ica 129, 130–134 (2016).
[3] Bakos, G. and Gaspa , “Finding and Cha ac e izing a La ge and Di e se Popula ion o T ansi ing Exoplane s
wi h HATSou h in Suppo o NASA Space Missions,” NASA P oposal #16-XRP16-70 (2016).
[4] Bigongia i, C. and Conso ium, C., “The Che enko Telescope A ay,” Nuclea and Pa icle Physics P o-
ceedings 279, 174–181 (2016).
[5] Race o, E., Oca˜na, F., and Ponz, D., “Towa ds an au onomous elescope sys em: he Tes -Bed Telescope
p ojec ,” Highligh s o Spanish As ophysics , 828–833 (2015).
[6] Saunde s, E. S., Lampoudi, S., Lis e , T. A., No bu y, M., and Walke , Z., “No el scheduling app oaches
in he e a o mul i- elescope ne wo ks,” in [SPIE As onomical Telescopes+ Ins umen a ion], 91490E (8
2014).
[7] Wang, F., Deng, H., Guo, L., and Ji, K., “A Su ey on Scien i ic-Wo k low Techniques o E-science in
As onomy,” in [2010 In e na ional Fo um on In o ma ion Technology and Applica ions], 417–420, IEEE
(7 2010).
[8] Kub´anek, P., “S a us, upg ades, and ad ances o RTS2: he open sou ce as onomical obse a o y man-
age ,” in [SPIE As onomical Telescopes+ Ins umen a ion], 99132U, In e na ional Socie y o Op ics and
Pho onics (7 2016).
[9] Denny, R., “A Web-Remo e/Robo ic/Scheduled As onomical Da a Acquisi ion Sys em,” in [Telescopes
om A a Con e ence], 47 (2011).
[10] Ye, Q.-Z., “Fo ecas ing Cloud Co e and A mosphe ic Seeing o As onomical Obse ing: Applica ion and
E alua ion o he Global Fo ecas Sys em,” Publica ions o he As onomical Socie y o he Paci ic 123, 113
(2011).