1
SILVA FENNICA
Sil a Fennica ol. 52 no. 3 a icle id 9986
Ca ego y: esea ch no e
h ps://doi.o g/10.14214/s .9986
h p://www.sil a ennica. i
Licenced CC BY-SA 4.0
ISSN-L 0037-5330 | ISSN 2242-4075 (Online)
The Finnish Socie y o Fo es Science
Ninni Saa inen1,2, Joanne C. Whi e1,3, Michael A. Wulde  3, Annika Kangas 4,
Saka i Tuominen 5, Ville Kanka e1, Ma kus Holopainen1, Juha Hyyppä 6 and
Mikko Vas a an a 2
Landsa a chi e holdings o Finland: oppo uni ies
o o es moni o ing
Saa inen N., Whi e J.C., Wulde M.A., Kangas A., Tuominen S., Kanka e V., Holopainen M.,
Hyyppä J., Vas a an a M. (2018). Landsa a chi e holdings o Finland: oppo uni ies o o es
moni o ing. Sil a Fennica ol. 52 no. 3 a icle id 9986. 11 p. h ps://doi.o g/10.14214/s .9986
Highligh s
• The 45-yea Landsa a chi e con ained 30 076 images o Finland by Decembe 31, 2017.
• 16.3% o hese we e acqui ed wi hin ±30 days o Augus 1 (no he n hemisphe e summe ),
ha e <70% cloud co e , and a 30 m spa ial esolu ion.
• Using ime se ies analyses, hese da a p o ide unique in o ma ion ha complemen s o he
da ase s a ailable o o es moni o ing and assessmen in Finland.
Abs ac
The e is g owing in e es in he use o Landsa da a o enable o es moni o ing o e la ge
a eas. F ee and open da a access combined wi h high pe o mance compu ing ha e enabled new
app oaches o Landsa da a analysis ha use he bes obse a ion o any gi en pixel o gene a e
an annual, cloud- ee, gap- ee, su ace e lec ance image composi e. Finland has a long his o y o
inco po a ing Landsa da a in o i s Na ional Fo es In en o y o p oduce o es in o ma ion in he
o m o hema ic maps and small a ea s a is ics on a a ie y o o es a ibu es. He ein we explo e
he spa ial and empo al cha ac e is ics o he Landsa a chi e in he con ex o o es moni o ing
in Finland. The Uni ed S a es Geological Su ey Landsa a chi e holds a o al o 30 076 images
(1972–2017) o 66 scenes (each 185 km by 185 km in size) ep esen ing he e es ial a ea o
Finland, o which 93.6% we e acqui ed since 1984 wi h a spa ial esolu ion o 30 m. App oxima ely
16.3% o he a chi ed images ha e desi ed composi ing cha ac e is ics (acqui ed wi hin Augus 1
±30 days, <70% cloud co e , 30 m spa ial esolu ion). Da a om he Landsa a chi e can aug-
men o es moni o ing e o s in Finland, p o ide new in o ma ion o science and applica ions,
and enable e ospec i e, sys ema ic analyses o cha ac e ize he de elopmen o Finnish o es s
o e he pas h ee decades. The capaci y o moni o ends based upon his mul i-decadal eco d
wi h he addi ion o new measu emen s is o bene i o mul isou ce in en o ies and o e s na ion-
ally comp ehensi e spa ially-explici da ase s o a wide ange o s akeholde s and applica ions.
Keywo ds Landsa ime se ies; sa elli e; na ional o es in en o y
Add esses 1 Depa men o Fo es Sciences, Uni e si y o Helsinki, P.O. Box 27, FI-00014
Uni e si y o Helsinki, Finland; 2 School o Fo es Sciences, Uni e si y o Eas e n Finland,
P.O. Box 111, FI-80101 Joensuu, Finland; 3 Canadian Fo es Se ice, (Paci ic Fo es y Cen e ),
Na u al Resou ces Canada, 506 Wes Bu nside Road, Vic o ia, BC, V8Z 1M5, Canada; 4 Na u al
Resou ces Ins i u e Finland (Luke), Bioeconomy and en i onmen , Yliopis oka u 6, FI-80100
Joensuu, Finland; 5 Na u al Resou ces Ins i u e Finland (Luke), Bioeconomy and en i onmen ,
2
Sil a Fennica ol. 52 no. 3 a icle id 9986 · Saa inen e al. · Landsa a chi e holdings o Finland: oppo uni ies…
La oka anonkaa i 9, FI-00790 Helsinki, Finland; 6 Depa men o Remo e Sensing and Pho og am-
me y, Finnish Geospa ial Resea ch Ins i u e, Na ional Land Su ey o Finland, Geodee in inne
2, FI-02431 Masala, Finland
E-mail [email p o ec ed]
Recei ed 28 Ma ch 2018 Re ised 12 June 2018 Accep ed 13 June 2018
1 In oduc ion
The Landsa p og am has been acqui ing da a o he Ea h’s su ace since 1972, and since 1982 he
da a has been acqui ed a a spa ial esolu ion o 30 m. The Landsa p og am hi he o u ilized h ee
30-m senso s: Landsa Thema ic Mappe (TM; Landsa s 4 and 5), Enhanced Thema ic Mappe Plus
(ETM+; Landsa 7), and Ope a ional Land Image (OLI; Landsa 8). Da a om he Mul i-Spec al
Scanne (MSS) senso is a ailable wi h a 60 m spa ial esolu ion. In 2008, all newly acqui ed and
a chi ed Landsa images in he Uni ed S a es Geological Su ey (USGS) a chi e we e made eely
and openly a ailable (Woodcock e al. 2008), ad ancing he accessibili y o all coun ies o use
Landsa da a o gene a e in o ma ion ele an o science, policy, and epo ing needs (Wulde
e al. 2012). The spec al and spa ial p ope ies o Landsa make i pa icula ly use ul o o es
moni o ing (Cohen and Gowa d 2005) and he ad en o ime se ies analyses has u he s eng h-
ened his capaci y (Bansko a e al. 2014). The spa ial and empo al na u e o he Landsa a chi e
is no uni o m globally, and no all acqui ed da a is ound wi hin he cen al a chi e. Th ough he
Landsa Global A chi e Consolida ion ini ia i e, he USGS and In e na ional Coope a o s ha e
combined o ensu e all p e iously acqui ed da a, downloaded and s o ed egionally, a e added o
he cen al a chi e (Wulde e al. 2016).
The gene a ion o image composi es wi h Landsa ime se ies (LTS) has become inc eas-
ingly common (Hansen and Lo eland 2012). Composi ing app oaches use a ule-based app oach o
selec om a ailable obse a ion o any gi en pixel, gene ally de e mined om wi hin a desi ed
empo al window o add ess seasonali y and o mee speci ied in o ma ion needs (G i i hs e al.
2013; Whi e e al. 2014). These bes -a ailable-pixel (BAP) composi es o e come issues esul ing
om clouds, haze, and ela ed shadows, which can o he wise p e en assembly o an annually
ep esen a i e co e age o image y. Mo eo e , a equen LTS da a allows o he gene a ion o
p oxy pixel alues in yea s when he e is no bes obse a ion o a gi en pixel (i.e. illing da a
gaps; He mosilla e al. 2015). The esul is a cloud- ee, gap- ee, wall- o-wall, annual su ace
e lec ance BAP composi e. Consecu i ely, a s ack o hese annual BAP composi es, ep esen ing
se e al decades, may be used o ime se ies analyses (Zhu 2017), suppo ing he cha ac e iza ion
o o es dis u bance and eco e y o e as a eas (Sen e al. 2017; Whi e e al. 2017).
In e na ional o es moni o ing p og ams and ag eemen s ela ed o clima e change equi e
na ional-le el in o ma ion abou o es esou ces. The Finnish Na ional Fo es In en o y (NFI) has
been p o iding in o ma ion on Finland’s o es s since he 1920s (Tomppo e al. 2010; Kangas e
al. 2018). The NFI is based on s a is ical sampling o ield measu emen s including cha ac e is ics
ela ed o o es heal h and biodi e si y, along wi h adi ional o es in en o y a ibu es. In o ma-
ion p o ided by he NFI is used as he basis o na ional and egional-le el s a egic o es -planning
scena ios o imbe p ocu emen , ha es s, and sil icul u al ea men s, as well as o es ima ing
o es ca bon budge s and assessing he sus ainabili y o o es managemen .
Based on he need o ob ain eliable o es esou ce in o ma ion o a eas smalle han would
be achie able wi h NFI ield da a only, he de elopmen o mul isou ce-NFI (MS-NFI) s a ed in
1989. In he MS-NFI, Landsa da a (also Sen inel and SPOT image y) a e used oge he wi h digi al
maps and measu emen s om NFI ield plo s o p oducing wall- o-wall hema ic maps o o es
a ibu es and municipal-le el o es s a is ics. Al hough es ima es o he MS-NFI and NFI (based
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on ield plo s only) a e simila a he egional le el, he p edic ion e o a he le el o indi idual
pixel is gene ally ela i ely high (Tomppo e al. 2014; Tuominen e al. 2017). As he me hods used
o gene a e he MS-NFI a e unde con inuous de elopmen (Tomppo e al. 2008) and he a ibu es
ha e no been p edic ed using consis en app oach, he compa abili y be ween hema ic maps a
pixel o s and le el om di e en MS-NFIs can be challenging.
De ailed spa ial and empo al analyses o he Landsa a chi e o speci ic applica ions a e
uncommon, pa icula ly o a eas ou side No h Ame ica (Whi e and Wulde 2013). Mo eo e ,
he capaci y o he Landsa a chi e o e ospec i ely suppo he de elopmen o a his o ic eco d
o o es change and analyses in he con ex o o es moni o ing in o ma ion needs in no he n
Eu opean bo eal o es s has he e o o e no been documen ed. To be e unde s and he de elopmen
and impac s o na u al dis u bances and managemen ac i i ies on Finnish o es s h ough ime,
spa ially-explici o es change in o ma ion is equi ed. The Landsa p og am p o ides a aluable
long- e m eco d o science and applica ions. Howe e , he comp ehensi eness o he Landsa
a chi e o Finland has no ye been documen ed and he po en ial o LTS o spa ially-explici
o es moni o ing in Finland emains o be de e mined. The e o e, he aim o his s udy was o
in es iga e he spa ial and empo al ex ensi eness o he USGS Landsa a chi e o he suppo o
long- e m o es moni o ing in Finland.
2 Da a and me hods
Me ada a o all images acqui ed since he beginning o he Landsa p og am in 1972 un il
Decembe 31, 2017 and held in he USGS Landsa a chi e we e downloaded. Me ada a we e
p o ided sepa a ely o Landsa s 1–3 (MSS), Landsa s 4–5 (MSS and TM), Landsa 7 (ETM+),
and Landsa 8 (OLI). All Landsa me ada a o Landsa 4–5 TM, Landsa 7 ETM+, Landsa 8
OLI and P e-Collec ion me ada a o Landsa 1–5 MSS a e a ailable a h ps://landsa .usgs.go /
landsa -bulk-me ada a-se ice. In his analysis, we included he unique scene iden i ica ion numbe ,
senso , acquisi ion da e, Wo ldwide Re e ence Sys em (WRS) pa h and ow, as well as pe cen
cloud co e age om he me ada a. The WRS is he e e ence sys em used o pa i ion he Ea h in o
Landsa scenes, each wi h dimensions o 185 km × 185 km; Landsa s 1–3 used WRS-1 whe eas
Landsa 4 and subsequen Landsa sa elli es ha e used WRS-2. The numbe o images acqui ed is
analogous o he numbe o obse a ions o each scene.
Landsa image y acqui ed wi hin ±30 days o Augus 1 (no he n hemisphe e summe ; Julian
da e 213) has been conside ed sui able o BAP composi ing and o es moni o ing (G i i hs e
al. 2013; Whi e and Wulde 2013; Whi e e al. 2014; He mosilla e al. 2015). Based upon simila
seasonali y and expec a ion o peak pho osyn hesis mid-summe , he empo al dis ibu ion o images
was analyzed wi hin his ime window o cha ac e ize he po en ial o he Landsa a chi e holdings
o o es moni o ing pu poses. Fu he mo e, MSS e a images we e excluded om hese analyses
because o he cu en challenges in inco po a ing he di e en spa ial and spec al p ope ies o
hese da a in o ime se ies analyses (P lugmache e al. 2012; B aa en e al. 2015). Thus, we ha e
only included he images acqui ed om 1984 onwa ds o o es moni o ing pu poses. Addi ionally,
a h eshold o cloud co e was se o 70% based on p e ious s udies (G i i hs e al. 2013; Whi e
and Wulde 2013). The 70% maximum cloud co e is selec ed o ensu e some minimum le el o
clea pixels and su icien g ound isibili y o aid in geome ic ec i ica ion p ocedu es (Whi e e
al. 2014). Ou analyses also inco po a ed he egional a iabili y o he Landsa a chi e sui able
o BAP composi ing and o es moni o ing (i.e. a composi ing window o Augus 1 ±30 days
and cloud co e <70%), by cha ac e izing a chi e holdings o he 13 Public Se ice Uni s o he
Finnish Fo es Cen e.
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We calcula ed he a e age numbe o images pe scene and pe yea cu en ly in he a chi e
(as o Decembe 31, 2017) mee ing he BAP composi ing c i e ia. These numbe s we e hen summed
in he o e lapping a eas be ween scenes, o demons a e he heo e ical impac on obse a ion
yield esul ing om Landsa scene o e lap. To demons a e he ealized po en ial o he a chi e o
image composi ing, we c ea ed annual BAP composi es o a 5.3 Mha a ea ( ep esen ing 11 unique
WRS-2 pa h/ ows) in sou he n Finland o 1984–2017 ollowing he app oach desc ibed in Whi e
e al. (2014) and He mosilla e al. (2016). We hen calcula ed he o al numbe o obse a ions
(i.e. he numbe o yea s wi h clea pixels used in he composi es). As a esul , we demons a e he
heo e ical impac o Landsa scene o e lap on he gene a ion o BAP image composi es in Finland.
3 Resul s
As o Decembe 31, 2017, he e we e a o al o 30 076 images in he Landsa da a a chi e o Finland.
Mos o he images we e acqui ed wi h he TM (42.8%) and ETM+ (31.8%) senso s (combined
74.6%), ollowed by OLI (19.1%) and MSS (6.4%) (Fig. 1). The dis ibu ion o a ailable da a
h ough ime is no consis en : he numbe o images is limi ed p io o 1984 and o 1991–1993,
and 1995–1997. Mo e han wo- hi ds (68.5%) o he a chi ed images we e acqui ed a e he
launch o Landsa -7 ETM+, enabled by a sys ema ic long- e m acquisi ion plan (A idson e al.
2001). Image acquisi ions inc eased ma kedly wi h he launch o Landsa 8 (OLI) in Feb ua y
2013; a e only 5 yea s o ope a ion, OLI da a ep esen 20% o he a chi ed holdings o Finland.
Mo eo e , he annual a e a which OLI has acc ued da a in he a chi e since 2013 is mo e han
double ha o TM and ETM+ (Fig. 1).
Fig.1. To al numbe o a chi ed Landsa images acqui ed o Finland, by yea and senso . MSS = Mul i-Spec al Scan-
ne , TM = Thema ic Mappe , ETM+ = Enhanced Thema ic Mappe Plus, and OLI = Ope a ional Land Image .
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Fig. 2. Pe cen age o all a chi ed Landsa images acqui ed o Finland and hei acquisi ion day o yea (A) as
well as numbe o a chi ed Landsa images acqui ed o Finland wi hin ±30 days om he a ge day o yea
(Augus 1) and wi h cloud co e < 70%, by yea and senso (B). MSS = Mul i-Spec al Scanne , TM = The-
ma ic Mappe , ETM+ = Enhanced Thema ic Mappe Plus, and OLI = Ope a ional Land Image ..

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The o al numbe o a chi ed Landsa images o Finland acqui ed wi hin ±30 days o Augus
1 (Julian da e 213) was 8901, o which 8121 images (o 27.0% o he o al a chi e holdings) we e
acqui ed wi h a senso o he han MSS (Fig. 2A). Fo he BAP composi ing scena io (i.e. Augus 1
±30 days wi h <70% cloud co e ) he e we e 4897 images om TM, ETM+, and OLI, ep esen ing
16.3% o he o al a chi e holdings (Fig. 2B).
All he Public Se ice Uni s o he Finnish Fo es Cen e, wi h excep ion o Lapland, ha e
a minimum o 76 images pe Landsa scene acqui ed since 1984 mee ing he BAP composi ing
c i e ia, co esponding 72.3% o he land a ea o Finland (Fig. 3). The Sou hwes Finland and Åland
egions ha e he g ea es numbe o a chi ed Landsa images pe scene (>100).
The mean numbe o a chi ed images pe yea was g ea e in o e lap a eas be ween adjacen
scenes (Fig. 4A). Inc eased obse a ional densi y in o e lap a eas u he enables BAP composi -
ing app oaches, as hese a eas will ha e mo e po en ial obse a ions o BAP composi ing. This
po en ial o inc ease obse a ions is ealized when composi es a e gene a ed, as shown in Fig. 4B
ep esen ing annual BAP composi es gene a ed o 1984–2017. O e lap a eas ha e mo e images
pe yea and mo e yea s wi h obse a ions in he inal BAP composi es.
Fig. 3. To al numbe o images (1984–2017) o WRS-2 Landsa scenes co -
e ing Finland ha we e acqui ed wi hin ±30 days om he a ge day o yea
(Augus 1) and <70% cloud co e , by Public Se ice Uni s o he Finnish Fo es
Cen e.
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4 Discussion
LTS o e a unique oppo uni y o long- e m o es moni o ing. Al hough he a chi e holdings o
Finland a e no as ex ensi e as o No h Ame ica (Wulde e al. 2016), hey do p o ide possibili-
ies o inc easing knowledge abou de elopmen o Finnish o es s bo h spa ially and empo ally.
The NFI has p o ided s a is ics abou Finnish o es s since he 1920s, and MS-NFI om he ea ly
1990s. Howe e , he hema ic maps be ween di e en MS-NFIs a e no compa able hus, di ec
change de ec ion using hem is challenging. U iliza ion o LTS could he e o e enhance spa ially-
explici and e ospec i e analyses o explo a ions o changes in land use (i.e. o es ed a ea) o
suppo g eenhouse gas epo ing, o example. Howe e , i de ailed in o ma ion abou he amoun
o emo ed wood is o in e es , da a om ield measu emen s would be equi ed.
The 1980s and 1990s ep esen ed a pe iod o ins abili y in he Landsa p og am, wi h
Landsa da a p iced o cos eco e y by NOAA, and p og amma ic con ol o Landsa s 4 and 5
(and de elopmen o Landsa 6) ans e ed om he Uni ed S a es go e nmen (NOAA) o he
p i a e sec o (EOSAT) om 1985 un il 2001. Simul aneously, cos s o Landsa da a inc eased
d ama ically and demand ell. The Landsa a chi e holdings su e ed mos signi ican ly du ing
his ime. In he absence o a long- e m acquisi ion plan, and aced wi h subs an ial da a downlink
cos s, acquisi ions became inc easingly US-cen ic and we e demand-d i en (Gowa d e al. 2017).
Al hough In e na ional Coope a o s con inued o downlink da a, hey we e also applying he same
Fig. 4. Mean numbe o images (1984–2017) pe yea o WRS-2 Landsa scenes co e ing Finland ha we e
acqui ed wi hin ±30 days om he a ge day o yea (Augus 1) and wi h <70% cloud co e (A). Realized num-
be o obse a ions (i.e. numbe o yea s wi h clea pixels o composi ing) om bes -a ailable pixel (BAP)
composi es (1984–2017) o a sample a ea in sou he n Finland (B).
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cos - eco e y model as EOSAT, wi h a simila da a p icing s uc u e. Faced wi h signi ican unding
sho alls om he US Go e nmen , EOSAT ceased p ocessing Landsa da a by he end o 1992
and did no esume p ocessing un il 1994. The MS-NFI was i s in oduced du ing he eigh h NFI
(ca ied ou be ween 1986 and 1994). Concu en ly, he co e age o he Landsa a chi e in Finland
is e y limi ed, pa icula ly o 1991–1997 (excep o 1994).
Despi e spa ial gaps in a chi e holdings, o e lap be ween adjacen scenes ensu es adequa e
spa ial and empo al co e age o enable BAP composi ing (G i i hs e al. 2013; Whi e e al. 2014).
Fu he mo e, app oaches o change de ec ion, among o he s (He mosilla e al. 2016; Zhu 2017),
enable a spa ially-explici his o ic eco d o o es change o be cons uc ed om he LTS, which
can enhance he cha ac e iza ion o he de elopmen o Finnish o es s o e ime. Consequen ly,
es ima es o ha es ed o bu ned a eas can be iden i ied as well as when land use class om o es
has changed. In addi ion o he cap u e and documen a ion o o es dis u bances, LTS su ace
e lec ance alues ha e demons a ed u ili y o moni o ing and quan i ica ion o ege a ion eco e y
ollowing i e and ha es (Whi e e al. 2017). As assessmen s o o es eco e y using ield plo s
a e ypically spa ially and empo ally cons ained (Ba els e al. 2016), he capaci y o assess bo h
dis u bance and eco e y o e la ge a eas wi h LTS da a can augmen plo -based analyses wi h
bo h empo ally and spa ially exhaus i e in o ma ion on eco e y.
The “always on” s a us o OLI has esul ed in an inc ease in he numbe and seasonal dis-
ibu ion o images o Finland. This inc eased da a collec ion o e s enhanced possibili ies o
he u u e o o es moni o ing (i.e. om annual o wi hin yea BAPs). Mo eo e , he ela i ely
sho u na ound ime be ween acquisi ion and a ailabili y o he images in he Landsa a chi e as
analysis eady da a enables he de elopmen o nea - eal ime applica ions (Zhu and Woodcock
2014). Howe e , he s eng h o LTS is long- e m o es moni o ing wi h he unique ime ame
o obse a ions.
In combina ion wi h Sen inel-2 sa elli es, acqui ing da a wi h simila cha ac e is ics o OLI
da a and a e being made openly and eely a ailable (Li and Roy 2017), composi ing algo i hms
can become mo e obus , bu essing he complemen a y ole o op ical sa elli e image y o expand
suppo Finnish o es moni o ing ac i i ies. Due o spa ial and spec al complemen a i y be ween
Landsa and Sen inel-2 (D usch e al. 2012), and gi en p og ess owa ds c oss-calib a ion o hese
da a (Zhang e al. 2018), Landsa a chi al image y can p o ide a baseline agains which ends
de i ed om Sen inel-2 obse a ions can be compa ed (Wulde e al. 2015, 2018). Mo eo e , syn-
e gies be ween Landsa and Sen inel-2 p o ide oppo uni ies o sho e e isi imes and imp o e
he likelihood o cloud- ee obse a ions o suppo composi ing app oaches (Li and Roy 2017).
5 Conclusions
Global co e age o Landsa da a has luc ua ed o e ime due o logis ical and p og amma ic ac-
o s. The USGS Landsa a chi e holdings o Finland ep esen mo e han h ee-decades o da a
acqui ed since 1984 wi h a 30 m spa ial esolu ion. These a chi e holdings a e su icien ly dense o
suppo he de elopmen o annual image composi es ha can consecu i ely be used o long- e m
o es moni o ing. Re ospec i ely, hese da a p o ide a use ul sou ce o baseline in o ma ion o
o es moni o ing in he con ex o clima e change, and mo eo e , could suppo a b oad sui e o
in o ma ion needs and scien i ic applica ions, such as spa ially-explici in es iga ions o changes
in o es connec i i y and composi ion o e ime, and a ia ion in egional ends in o es eco -
e y. These da a complemen he dense ne wo k o NFI ield plo s and p o ide new in o ma ion o
o es moni o ing a egional and na ional le els.
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Acknowledgemen s
This esea ch was unde aken wi h suppo om he Academy o Finland h ough he Cen e o
Excellence in Lase Scanning Resea ch (p ojec numbe 272195) and he ‘Ea h Obse a ion o
In o m Canada’s Clima e Change Agenda (EO3C)’ p ojec join ly unded by he Canadian Space
Agency (CSA), Go e nmen Rela ed Ini ia i es (GRI) p og am, and he Canadian Fo es Se ice
(CFS) o Na u al Resou ces Canada. T. He mosilla and G. Hoba a e hanked o acqui ing he
Landsa da a and p ocessing he annual bes -a ailable pixel and p oxy (BAP) image composi es
used in he example shown in Fig. 4B.
Re e ences
A idson T., Gasch J., Gowa d S.N. (2001). Landsa 7’s long- e m acquisi ion plan – an inno a i e
app oach o building a global image y a chi e. Remo e Sensing o En i onmen 78(1–2):
13–26. h ps://doi.o g/10.1016/S0034-4257(01)00263-2.
Bansko a A., Kayas ha N., Falkowski M.J., Wulde M.A., F oese R.E., Whi e J.C. (2014). Fo es
moni o ing using Landsa ime se ies da a: a e iew. Canadian Jou nal o Remo e Sensing
40(5): 362–384. h ps://doi.o g/10.1080/07038992.2014.987376.
Ba els S.F., Chen H.Y.H., Wulde M.A., Whi e J.C. (2016). T ends in pos -dis u bance eco e y
a es o Canada’s o es s ollowing wild i e and ha es . Fo es Ecology and Managemen
361: 194–207. h ps://doi.o g/10.1016/j. o eco.2015.11.015.
B aa en J.D., Cohen W.B., Yang Z. (2015). Au oma ed cloud and cloud shadow iden i ica ion
in Landsa MSS image y o empe a e ecosys ems. Remo e Sensing o En i onmen 169:
128–138. h ps://doi.o g/10.1016/j. se.2015.08.006.
Cohen W.B., Gowa d S.N. (2004). Landsa ’s ole in ecological applica ions o emo e sens-
ing. BioScience 54(6): 535–545. h ps://doi.o g/10.1641/0006-3568(2004)054[0535:L-
RIEAO]2.0.CO;2.
D usch M., Del Bello U., Ca lie S., Colin O., Fe nandez V., Gascon F., Hoe sch B., Isola C.,
Labe in i P., Ma imo P. (2012). Sen inel-2: ESA’s op ical high- esolu ion mission o GMES
ope a ional se ices. Remo e Sensing o En i onmen 120: 25–36. h ps://doi.o g/10.1016/j.
se.2011.11.026.
Gowa d S.M., Williams D.L., A idson T., Rochchio L.E.P., I ons J.R., Russel C.A., Johns on
S.S. (2017). Landsa ’s endu ing legacy: pionee ing global land obse a ions om space.
Ame ican Socie y o Pho og amme y and Remo e Sensing, Be hesda, Ma yland. 586 p.
ISBN 1-57083-101-7.
G i i hs P., an de Linden S., Kuemme le T., Hos e P. (2013). A pixel-based Landsa com-
posi ing algo i hm o la ge a ea land co e moni o ing. IEEE Jou nal o Selec ed Topics in
Applied Ea h Obse a ions and Remo e Sensing 6(5): 2088–2101. h ps://doi.o g/10.1109/
JSTARS.2012.2228167.
Hansen M.C., Lo eland T.R. (2012). A e iew o la ge a ea moni o ing o land co e change
using Landsa da a. Remo e Sensing o En i onmen 122: 66–74. h ps://doi.o g/10.1016/j.
se.2011.08.024.
He mosilla T., Wulde M.A., Whi e J.C., Coops N.C., Hoba G.W. (2015). Regional de ec ion,
cha ac e iza ion, and a ibu ion o annual o es change om 1984 o 2012 using Land-
sa -de i ed ime-se ies me ics. Remo e Sensing o En i onmen 170: 121–132. h ps://doi.
o g/10.1016/j. se.2015.09.004.
He mosilla T., Wulde M.A., Whi e J.C., Coops N.C., Hoba G.W., Campbell L.B. (2016). Mass