The detection of a phenological event (the brown wave-vegetation senescence) for specific forest and crop types using ERTS-1 imagery is described. Data handling techniques included computer analysis and photo interpretation procedures. Computer analysis of ERTS-1 multispectral scanner digital tapes in all bands was used to give the relative changes of spectral reflectance with time of forests and specified crops. These data were obtained for a number of the study's twenty-four sites located within four north-south corridors across the United States. Analysis of ground observation photography and ERTS-1 imagery for sites in the Appalachian Corridor and Mississippi Valley Corridor indicates that the recession of vegetation development can be detected very well. Tentative conclusions are that specific phenological events such as crop maturity or leaf fall can be mapped for specific sites and possibly for entire regions

Ashley, M. D.

Blair, B.

Dethier, B. E.

Hopp, R. J.

English

NASA Technical Reports Server

Paper A 19 
PHENOLOGY SATELLITE  EXPERIMENT^ 
Bernard E. Dethier, Marshall D. Ashley, Byron Blair and Richard J. tiopp2 
ABSTRACT 
The detection of a phenological event ( the  brown .gave-vegetation 
senescence) f o r  s p e c i f i c  fo res t  and crop types using ERl'S-1 imagery is  
described. Data handling techniques included computer analys is  and 
photo in te rp re ta t ion  procedures. Computer: ana!.ysis of ERTS-1 multi- 
spec t ra l  scanner d i g i t a l  tapes i n  a l l  bands was used t o  give the 
r e l a t i v e  changes of spec t ra l  ref lec tance  with time of f o r e s t s  and 
specified crops. These da ta  were obtained f o r  a number of the study's 
twqty-f our s i t e s  located within four north-south corridors across the  
Unites States.  
Analynis of ground observation photography and ERTS-1 imagery 
for s i t e s  i n  the  Appalachian Corridor and Mississippi  Valley Sorridor 
indicates  t h a t  the  recession of vegetat ion development can be detected 
very w e l l .  Tentative cm:lusions a r e  t h a t  s p e c i f i c  phenological events 
such a s  crop maturity or  I r a t  L'all can be mpped f o r  s p e c i f i c  s i t e s  and 
possibly f o r  e n t i r e  regions. 
Preliminary analys is  besed on a number of samples i n  mixed 
deciduous hardwood stands indicate  t h a t  as senescence proceeds both the  
r a t e  of change and di f fereuces  in color  hnollg epo,cies can be detected. 
T h t s  w i l l  permit timber surveys by s p e c ~ e s  ove; i a rge  areas  and the 
determination of c o n d i t i m s  of wi ld l i f e  habi ta ts .  
The ro les  of the Sta te  Agricul tars l  Experiment Sta t ion and the  
cooperative s t a t e  extension agent and s p e c i a l i s t  i n  d i s s c d n a t i n g  
methods of applying ERTS data  t o  agr icu l tu ra l ,  fo res t ry  and w i l d l i f e  
management pract ices  a r e  riLso discussed. 
'project cc-investigators: J. A. Asleson, Montana S t a t e  Unlv.; M. F. 
Baumgardner, Purdue Univ.; N. L. S a f i e l d ,  NOAA; J. M. Caprio, 
Montana S ta te  Univ.; W. C. Kennard, Univ. of Conn.; M. D. Magnuson, 
NOM; J. W. b s e ,  Jr., Ter. A & H Univ.; aod M. T. Vittm, Geneva 
Erp. Sta., Geueva, N.Y. 
2 ~ t o a p h e r i c  Sciezicefi, Cornall Univ. , I t h u r ,  N.Y. ; F m e i ~ t  Reaourca~ ,
Univ. of Maine, Orano, Bb. ; Ag~:onomy, Purdue Univ., Lafayette,  Ind. ; 
and Plant and So i l  Science, Univ. of Vermont, Burlingtan, V t .  
https://ntrs.nasa.gov/search.jsp?R=19730019494 2020-03-17T09:03:47+00:00Z
I. INTRODUCTION 
The term "phenolcgy" appears t o  'time been f i r s t  applied i n  1853 
by t h e  SeTpian bo tan i s t ,  Charles Morren, t o  t ha t  branch of sc ience  which 
s tud ie s  pe.r .odic phenomena i n  the  plant  2-2 aii:nr;ri r j i j r ld  insofar  a s  they 
depend vgon the c i imate  of any l o c a l i t y .  The word phenology i t s e l f  is  
derived from rile Creek word "phaino", meaning t o  show. P lan t s  can be 
used a s  i n d i c . ~ t o r s  of  c l ima t i c  d i f f e r e n c ~ s  because the  times cf occur- 
rence of phenological events  of many p l an t s  i s  t o  a l a r p e  degree cun- 
t r o l l e d  by the  weather. Thus, phenology r ep resen t s  a m e r g i n ~  of t h e  
meteorol.ogica1 and b io logica l  sciences,  each c o n t r i b u t i r ~ g  something t o  
tht.  o ther .  
S c i e n t i s t s  hrvc known fo r  many de.-sdes t h a t  p lant  s p t c i e s  a r e  
exce l len t  i nd ica to r s  of envi ronment~l  condit ions.  Some phenological 
indica tor  p l an t s  r e f l e c t  c l ima t l c  c o n t r a s t s  between loca t ions  through 
t h c i r  d i f f e r e n t i a l  r a t e  of seasonal development; o ther  spec ies  i nd ica t e  
s o i l  moisture condit ions.  depth t o  water t a b l e ,  p r ?  ~ u t r i e n t  s t a t u s  of 
s o i l s .  Two phenoiogiral sequences a r e  observed i n  the  Phenolog: ; s t e l -  
l l t e  Experiment: 
1. The Green Wave: A record of t h e  gzographical 
progression with time of f o l i a g e  development 
over wide areae.  Phis  is t h e  f i r s t  s t e p  t h a t  
must be taken toward a real time inventory of 
t h e  y i e ld  p o t e n t i a l ,  y i e ld  r e a l i z a t i o n  and crop 
management over extended crop and t i m b e  produc- 
ing a r e a s  of t h e  nat ion.  
2. The Brown Wave: A record of t h e  geographical 
progression wi th  time of vegeta t ion  Renescence 
(maturation of crops,  l e a f  colorat iot l ,  and leaf  
absc iss ion) .  Ii piaye t h e  analogoar rcle i n  
t h e  autumn a s  t h e  Green Wave phenomenon does i n  
t h e  spr ing  i n  tenas  of phenological p red ic to r s  
f o r  vegeta t ion  management. 
This  repor t  descr ibes  t h e  phenological changes during t h e  f a l l  
season (Brcwn Wave) de t ec t ab le  through s a t e l l i t e  scanner svetema. 
The research was conducted a t  24 site8 wi th in  four co r r ido r s :  
(1) t h e  Appalachian Corridor from l h i n e  t o  North Carolina,  (2) t h e  
Miss is r ippi  Valley Corridor from Michigan t o  Texae, (3) t h e  Rocky 
b u n t a i n  Corridor fro= Montana t o  Arieoria, and (43 t h e  Columbia Valley 
Corridor i n  Warhington and Oregon (Fig. 1). Multirrpectral scanner 
da t a  from re l ec t ed  refpants In each co r r ido r  were analyzed and c o r r b  
l a t e d  with ground r t te  photography from corresponding megents .  
I 
a m -  
I--** 
F ~ C M  1. A - hppmkhka Emador, D - mbmlu ipp i  V d l a y  Cotridor, 
C - rocky Hamtab Corridor, II - alubi* Pallmy Cwridmr. 
The photographic ana lys i s  of khe Rocky Mountain and Cel?rmhla 
Val1 ey CorrLdors is being perforreti by Dr. Joseph Caprio, Montara Sta te  
Cniversity. 3r. John Touse, Texas A & M, i s  proceseLng t h c  MSS data 
F9r these  corrfdars and correlating sinilar data f r ~ m  la sites in R 
Great Plains Corridor for an asscciatcd ERTS-L project .  
The ERTG sr t e l l i t  5 ptnv ides  the only reasonable meane of making 
sgncptic ~ h e n o l o ~ i c a l  measurements over the interregional- areas 
described :n a t i m e  frame wW=h w t l l  a l l c w  oyeratienal ttse of the  
zesillts. The results described here are d:tiv,-d frsrl analysis o f  MSS 
s a a  from the Appalachian rind M i s s l s s j p p t  Co+rfders. 
11. DATA ZlUHLES AND METYIODS OF ANALYSTS 
IE:~~;cTY fro% a1 1 roux- nu1 tisprct~;t rrcannes (tlSS) bands f s being 
crralrinted. :?.taiid~i;-c! product3 used are 70 m t l  lirneter and 9x9 inch 
positl.ve transparenr l e a ,  9 ~ 9  Inch color infrared composf te  tranapar- 
enciee froa bands I r ,  5 ,  urrd 7 ,  and ccmyte:: earnpatable raper: kl-o.n a l l  
b.zn.lo. On-slte phot3:rarihb 02 the forest, crop, and rznge r i i tes  i s  
befng taken on a s i x  cia;* cyeZc ht each a i t c  eo that the  tiate of w::ery 
third st-t of pitoras c ~ i . ~ = P d ? s  with an ERTS overpnsa. Tilts  photography 
provides a h a s h  f o r  com~arlsun in t5e  ERTS d a t ~  enalyniii. 
C~rr.p!~tcr analysis aad photo Interpretation pzoeedurea are being 
.:94 t o  determine phenological chn~.ges.  Computer prnyi-nnn have heat 
written 3 y  ttlt: Laharstory For P p p l  icat :on% a €  Rmu t~ Smsf ng (LARS) , 
P ~ r d u c  Unlver%.fty, and the Renote Smelag C+nter (RSC), Texas A & Fl 
IttJ.vetsf.ty, to  express tho rt-lctivo refJ.*-.:.tnnce jn c ~ e ? l  baado 
Analysis of dnta from a l l  34 s i t e s  (Phcn:>lop,y S a t e l l i t c  Esperinent 
project  and 10 s i t e s  Great Pla ins  Corridor p ru jec t )  f o r  the Fa!? 
s;.ason i s  continuing. A t  t he  present tirue, sequent ia l  a n a l y s i s  of 
dzta  from the  Vermont, North Carolina, aud Indiana s i t e s  iz co5tplete. 
The average and d i s t r i b a t i o n  of the ref lec tance  i n  each band for a 
given dn te  have been plot ted  graphicel.1y t o  show the  spec t ra l  chsngcs 
with time. 
Photo in te rp re ta t io?  methods a r c  used t o  consizruct s imi lar  time 
sequences. Gray tone changes on the  black and white products a r e  
being evaluated a s  an indicator  of phenological change. E U S  imagery 
of the  V e m n t  t e s t  s-ite was examined f o r  t h i s  pa r t  of the  study. As 
more data  becomes avai lable ,  t b e  l apse  sequences showing the  coinci- 
dent chacges i n  vegetat ion on the  imagery and t h e  ground observation 
photography w t l l  be assembled. 
Another type of phenological time lapse  sequence is cur ren t ly  
being collected.  This sequence c o n s i s t s  of the  changzs i n  the  anount 
of fo res t  cover a s  measured from t h e  grocnd photography, using a 
Digicol model 4010-3Vensi ty  s l i c e r .  The Digicol has an e lec t ronic  
planimeter attachmes t which evaluates the  percent a rea  of d if f crent  
densi ty  l e v e l s  (e.g. sky versus fo l i age )  witt.in a photo. The changing 
Flzcentages between s e t s  of pitotography of t h e  same scene r e s u l t  from 
-3liage devdopment o r  recession. 
111. RESULTS AND DLSCUSSiON 
The r e l a t i v e  d i f ferences  i n  r e f l ec tances  f o r  an Indiana fo res t  
s i t e  a r e  i l l -us t ra ted  I n  Figure 2A. Reflectance i n  both bands 6 and 7 
decreased with each succeeding overpass. Tne ground observation 
photography a l s o  shows a s ign i f i can t  change during t h i s  e ight  week 
period. The .l.ecives i n  mid-September were f u l l y  developed and green 
whjle by the  October 19 overpass f a l l  colora t ion was well under way. 
Leaf f a l l  w a s  complete by November 24. !. s i a i l a r  ana lys i s  fur  two 
silccessive passes over the  Yorth Carolina s i t e  before l ea f  sencsclnce 
had s t a r t e d  shows, a s  would be expected, l i t t l e  chnr~ae i n  r e f l ec tance  
(Fig.2B). These cor re la t i cns  ind ica te  tha t  phenoiozical changca (Brown 
Wave) can be r e a d i l y  detected r'rom ERTS-1 data.  
The photo in te rp re ta t ion  ana lys i s  a l s o  has shown substant ive  
resu l t s .  On site -3qtography has docume.. ed the  f n l l  phenological 
changes a t  the  car 'ors '  s i t e s .  By evaluating t h e  coinplete s e t s  of 
photos, t h e  t i w p  TI cop davelopment and maturi ty,  l ea f  coloratiorr, and 
leaf  f a l l  can be determined f o r  t h e  d i f f e r a n t  geographical locations.  
Digicol measurements quantify these  w e n t s .  
The timing of vegetation senescancs t s  not s t r i c t l y  a function of 
l a t j  tude. I n  the  Appalachian corr idor  t h e  R O T ~ ~ I L J ~ I ~  h a r d w ~ d  leaves  a t  
the  Vermont site,  44'25'24 l a t .  (Nov. 4)  f e l l  before thoire at t h e  Orono, 
Figure 2. Histogram of the  coiz?ar&tiva upoc t r s l  rRsponsa of f o r e s t  t e s t  
s i t e s ,  (A) Laf ryo t ta ,  Indiana; (8) Raleigh, Nr ~ t h  Carolina. 
3bine ~ l t e ,  44.55'N lrt. (Nov. 12). I n  t h e  Mirs ior ippi  Corridor, or!: 
l t a v e r  I n  Mirrourl ,  38'46'N lrt. complotd  colorat ion (Nov. i 5 )  before 
tho le  a t  Lafayet ts ,  Indiana, 40°26'N l a t .  (Nov. 24). Elevation,  s o i l  
type, moiuturs, and o ther  enviromontal  f a c t o r s  a l s o  inflrienca tho 
timing oi phenological c-mate. 
ERTS-1 imagery used i n  conjunction with t h e  ground obsorv3tion 
photography sequences providcm evidence of the geogrvphical prugre.~sioa 
of vege t s t ion  develo~an,nt .  Figatas 3 and 4 show how sone pheno.logica1 
changes i n  crops and forest appear when corre la ted I n  t h i a  way. EFTS 
frames E-1079-15063 (October 10) and E-1096-15115 (October 27) i n  bands 
5 and 7 a r e  presented along with ground observation photography cf t h c  
t c s t  site near Richwnd, Vermont. The ground photos were takon on 
OcLo. ~r 1 0  and dovexber 4 ,  1972, the dates neares t  ERTS-1 overposees. 
Tho t e r r e s t r i a l  photos on October 10 a r e  of standing mature corn and a 
forested area containing north- hardi~ood species. The f o r e s t  1eaveu 
+.-rere near t h e  height of f a l l  colorat ion.  The l a t e r  set: of ground photon 
showls t h a t  t h e  corn hes heim harvaeted with only s tubble  ranmining i n  
t h e  f i o l d e  end the  leavcs a t  t h e  f o r e s t  rite have near ly  u l l  fa l len .  
Exminat ion of ;he corn f i e l d  and t h o  foror tcd nite on t h e  imagery 
verlf 16s these  events. 
Thh phertological p togression e.=n be detected usiug ef ther kanil 5 
or 7. 1aieil compared v i t h  the October 10 ir,az~ry (7ig. 3 )  the corn f1el.d 
appears ltghtcr in tone on the October 27 (Fig. 4 3 Lnagery in t h e  rod 
band and about the same tone or a l i t t l e  darker IF the infrared Sand, 
Perhaps t h i a  can be e x p i a l ~ e d  by the s o i l  RFA ~ t ~ t i b l e  hkvfnq relatively 
higher ref 1 eccanee f.n the. rer! wavelength than staqdj ng mature corn, 
whilu the j.a?rarcd i-eflsctancs remained about: the sume er was slightly 
Irrss for the  ~tubble and so i l .  The rr,d band olcrb ellows a ganeral 
inctcnsc in re El %craw 2 chtxtghcur t hc Vlnooski Rfver V R ~ ~ P . Y  and hnrd- 
wood forest areas. T t t ~  rhanee is nclt a@ pronounced i n  band 7 imagery. 
While the eufdenee from. a t a l y a i s  of band 7 is not conclusive, t h ~  
s n ~ l y s i s  of band 5 dees indlrate a rrlaf ionsnip between vegetative 
c ~ v a r ,  reflectance, and phenological chmge. The depletion oi chlorn- 
phyl L in the vegetative cover due to  lest fall and senascrnce of lower 
uec"ation results in 4 hisher reflectance of solar energ  in the red 
voye lenzths. The vot.p.ntial fur napping such cilangas over large arrnrl 
is evldcnt. 
I V .  APPLICATIONS 
Preliminary computer t e s t s  and a photo in te rp lc tn t ion  study of 
ixagery i n  bands 5 and 7 fo r  October 10 and 27 ind icz te  t h a t  such 
events a s  crop harvest  and leaf  f a l l  can be mapped f o r  spec i f i c  a reas  
and possibly f o r  e n t i r e  regions. Comparison imagery taken before and 
a f t e r  l ea f  f a l l  can be used t o  nap softwood and hardwood areas.  For 
example, a land use  ? ~ d  fo res t  c l a s s i f i c a t i o n  study was made using the  
October 27 MSS-5 imagery of the  area  around the  Richnond, \'ermcjnt t e s t  
s i t e .  O ~ l y  t h a t  a rea  which could be compared with a USGS topographic 
sheet  was mapped. The resul t i i lg  Cats is  shown i n  Table 1. 
Table 1. Forest and Land Use Class i f i ca t ion  
RicFacnd, Vermont t e s t  s i t e .  
Forest. 
Sof twood 
# ixeclwood 
Hardwood 
Area (Acres) Percent of T o g  
1883 34 
41 5 7 
532 10  
Other 
-.- 
Fields,  farms, urban 2483 4 5 
Water - 210 - 4 
5523 Acres 100 Percent 
These f igures  were obtained by t r ac ing  t h e  gray tone boundaries of cne 
land uses a s  seen from a projection of t h e  ERTS frame onto a base map 
( sca le  1:125,000) and then using a dot  gr id  t o  ge t  the  areas  i n  each 
c lass .  Only 20 t o  30 minutes were required t o  c l a s s i f y  t h e  5500 acres.  
This time can be considerably reduced through the  use  of computer 
techniques. 
Another appl ica t ion of t h e  Brown Wave ( leaf  f a l l )  is i n  *.he study 
of w i l d l i f e  h a b i t a t  condit ions and a v a i l a b i l i t y .  
Results  t o  d a t e  from t h e  phenology S a t e l l i t e  Experiment clhows the 
f e a s i b i l i t y  of t h e  development and re f  ineinent of phenoclimatic models 
s imi lar  t o  t h e  one i l l u s t r a t e d  i n  Figure 5 .  
The model presented is a world map shoring i s o l i n e s  f o r  t h e  green- 
ing of g rass  i n  spr ing i x ?  t he  northern hemisphere. The l i n e s  a r e  based 
on a number of refzrence  points  a.nd d a t a  ca lcula ted  from a mathematical 
model. 
L a t e l l i t e  da ta ,  such a s  t h a t  received from ERTS-1, w i l l  make world- 
wide phenol.ogica1 monitoring possible.  This is necessary t o  develop 
universa l ly  appl icable  phenocl.imatic models. 
Figure 5. Average da te  of the  Green Wave (greening of grass)  passage 
i n  the  northern hemosphere. 
For countr ies  with highly developed agr icu l tu re ,  such information 
would be useful  i n  charac te r i za t ion  of crop s t a t u s ,  y ie ld  predic t ton,  
and management planning. Phenological da ta  i n  less-developed countr ies  
cauld be useful  f o r  a g r i c u l t u r a l  land use  planning and f o r  determin-ing 
site s u i t a b i l i t y .  
I n  t h e  f i n a l  analys is ,  t h e  success of Earth Resources Technology 
S a t e l l - L ~ e c  v i l l  depend on t h e  u l t imate  use  of in terpre ted data. In t h e  
agricu' i u r a l ,  ro res t ry ,  and r e l a t e d  segments of t h e  econany these  d a t a  
w i l l  contr ibute  t o  decision-making of econoaic s ignif icance  i n  a n a g e -  
ment, prov5.de more accurate  es t imates  of acreage and y i e l d  fo recas t s  of 
many cormnodities. The means of disseminating the  in terpre ted dzta  to  
t h e  user is avai lable  through Cooperative S t a t e  Extension Service. 
Working wfth the  s c i e n t i s t s  from t h e  S t a t e  Agricul tcra l  Experiment 
Sta t ions ,  extensio:~ a p e c i d i s t v  could be tvained t o  incoi-porate satel- 
l t t e  derived inf ormat. ion Jn;o titei r s t a t e  advisory programs. 


Phenology satellite experiment

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server