8/14/2019 07-99-honduras

1/275 4 J u l y 1 9 9 9 PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING

C O L U M N

G r i d s & D a t u m s

THE REPUB LI C OF HONDURAS

The contents of this column reflect the views of the au-

thor, who is responsible for the f acts and accuracy of the

data presented herein. The contents do not necessarily re-flect the official views or policies of the American Society

for Photogrammetry and Remote Sensing and/ or the Uni-

versity of New Orleans.

Maya set t l ement a t Copn in

wes tern Honduras i s ev ident f rom

1000 BC. Columbus fi rs t set foot on

the American main land a t Tru j i l lo

i n n o r t h e rn Ho n d u ras i n 1 5 0 2 , an d

n am ed t h e co u n t ry a f te r t h e d eep

water off the Car ibbean coas t .

( Ho n d o m ean s d ep t h s i n S p an -

i sh . ) Comayagua was es tab l i shed as

the capi ta l in the cool h ighlands of

cen t r a l Ho n d u ras i n 1 5 3 7 , an d r e -

mained the pol i t i ca l and re l ig ious

center of the count ry unt i l Teg-

ucigalpa (Lempi ra Indian language

for s i lver mountain) became the

capi ta l in 1880. Honduras gained

i n d ep en d en ce f rom S p a i n i n 1 8 2 1.

I t was br ief ly par t o f independent

M ex ico , b u t t h en d ec l a red i n d ep en -

d en ce a s a s ep a ra t e n a t i on i n 1 8 3 8.

I t shares borders w i th Guatemala , El

Salvador , and Nicaragua.The north ern coast is on the Carib-

bean Sea and the coun trys only exi t

to the Pacific Ocean to the south is

through th e Gulf of Fonseca, a condo-

minium w ater body shared wi th El

Salvador and Nicaragua. The Nicara-

gua-Honduras border crosses the

Central American is thmus at i ts wid-

est part and is 917 km (573 miles)

long . Cont inuing d i sputes between

t h e t wo n a t i o n s l ed t o t h e s u b m i s -

s ion of the problem to the King of

Spain for arb i t ra t ion in 1906. The

mat ter was temporar i ly reso lved ,

but no surveying or mapping of the

b o rd e r was p e r fo rm ed a t t h a t t i m e .

Th e o l d es t k n o wn m ap , ca l l ed

Mapa Espaol Ofic ia l (Off ic ia l

S p an i s h M ap ) , was co m p i l ed i n

1527 by Fernando Coln , the son of

Admiral Chr i s topher Columbus .

P ro m i n en t f eat u res were m ap p ed o n

the nor thern coas t , bu t l i t t l e deta i l

of the count rys in ter ior was shown.

Th e f i r st co m p l e t e m ap o f Hon d u ras

was by Professor Jesus Agui lar Paz,a pharmacis t and car tographer . In

1915, he under took the labor to pro-

d u ce an ad eq u a t e m ap for u s e i n t h e

coun t rys schools w i thout offic ia l

s u p p o r t . Th e m ap was co m p i l ed a t a

scale of 1 :500,000, and i s ex t raord i -

n a r i l y ex ac t wh en t h e m e t h o d o f

compi la t ion (no geodet ic cont ro l ) i s

taken in to cons iderat ion . The pro-

fes s o r p u b l i s h ed h i s m ap i n 1 9 3 3 .

Th e Gu a t em al a -Ho n d u ras b o u n d ary

is 256 km (160 mi les ) long and ex-

tends between the Car ibbean Sea

and the t r i -poin t wi th El Salvador

on Cerro Monte Cr i s to (mou ntain) .

Th a t t r i -p o i n t i n Ho n d u ras i s i n t h e

Depar tamento de Ocotepeque (s ta te

or province) . Boundary d i sputes be-

t ween Ho n d u ras an d Gu a t em al a b e -

gan shor t ly af ter the d i sso lu t ion of

the Federat ion of Cent ra l America

i n 1 8 4 3 . In acco rd an ce w i t h t h e

terms of the Treaty of Arbitrat ion

that was s igned in Washington in

1 9 3 0 , t h e d i s p u t ed l i n e was s u b m i t -ted to th e Chief Jus t ice of the

Uni ted S ta tes for a deci s ion on the

del imi ta t ion of the boundary . Be-

cause avai lab le topographic data

were i n ad eq u a t e fo r t h e b o u n d ary

wo rk i n m an y o f t h e d i s p u t ed a reas,

the Tr ibunal d i rected the making of

an aer ia l photogrammetr ic survey .

Chief Jus t ice Hughes appoin ted

Sidney H. Bi rdseye of the U.S .

Coast & Geodetic Survey (USC&GS)

as Chief of the boundary demarca-

t ion comm iss ion af ter Mr. Bi rdseye

co m p l e t ed t h e p h o t o g ram m et r i c

map pin g of the area . B i rdseyes

commiss ion erected 1 ,028 p i l l ars

an d co m p l e t ed i t s wo rk b e t ween

1933 and 1936. The award of the

Specia l Boundary Tr ibunal was

b as ed o n t h e p r i n c i p l e o f u t i pos -

s ide t i s as of 1821. Thu s , the award

referred to the t er r i tory under the

adminis t ra t ive cont ro l of Guatemala

an d Ho n d u ras a t t h e t i m e o f t h e i r

i n d ep en d en ce f rom S p a i n . F u r t h e r -

more, El Salvador , Guatem ala , andHo n d u ras s i g n ed a p ro t o co l o n 2 6

March 1936 accept in g Cerro Monte

Cri s to as the t r i -poin t of the bound-

ar ies of the three s ta tes . A fascinat -

ing aspect of the Guatemala-Hondu-

ras boundary i s that par t o f the

b o u n d ary i s es t ab l is h ed o n t h e

r ight banks of the Tin to and

Motagua r ivers a t mean h igh water

mark , and in the event of changes

i n t h es e s t r eam s i n t h e co u r s e o f

t i m e , wh e t h e r d u e t o acc re ti o n , e ro -

s i o n o r av u l s i o n , t h e b o u n d ary s h a l l

fol l o w t h e m ean h i g h wa t e r m ark

u p o n t h e ac t u a l r i gh t ban ks o f

both r iv ers . (Emphas i s added) .

Bo u n d ar i e s co m m o n l y d o n o t

change wi th avuls ions . Apparent ly ,

t h i s was i n t en d ed t o av o id fu t u re

s q u ab b l es .

The Ocotepequ e Datum of 1935

was establ ished at Base Norte wh ere

fo

= 14 26 20.168 Nort h, lo

= 89

11 33.964 West of Greenwich, and

H o = 806.99 meters above mean sealevel . The defining geodetic azimuth

to Base Sur is: ao

= 235 54 21.790,

and the el l ipsoid of reference is the

Clarke 1866 where a = 6,378,206.4

meters and 1/f

= 294.9786982. The

corresponding astronomic observa-

t ions at that mountainous locat ion

are: Fo

= 14 26 13.73 North

(0.07), Lo

= 89 11 39.67 West

(0.045), and the d efining astro-

nomic azimu th to Base Sur is : ao

= 235 54 20.37 (0.28). The dif-

ference between these two set s of

coord inates i s due to the local

gravimet r ic def lect ion of the ver t i -

cal . There was no Grid sys tem asso-

cia ted wi th th i s Datum, a l though

that s not su rpr i s ing s ince Mr.

Birdseye was with the USC&GS.

Th e i r cu s t o m was t o co m p u t e t h e i r

chains of quadr i la tera l s in geodet ic

co o rd i n a t es .

C L I F F O R D J . M U G N I E R

8/14/2019 07-99-honduras

2/2PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING J u l y 1 9 9 9 7 55

C O L U M N

G r i d s & D a t u m s

No t h i n g m u ch h ap p en ed (geo d e t i cal l y ) an y wh ere i n

Cent ra l America d ur in g World War I I . Af ter the war , the

U.S . Army Map Serv ice (AMS) estab l i shed th e In ter

American Geodet ic Survey ( IAGS) headquar tered in the

U.S . Canal Zon e of Panam . Co-operat ive agreemen ts

negot ia ted wi th mos t count r ies in Lat in America in-

cluded the Republ ic of Honduras . In November of 1946,

the Comis in Geogrfica Nacion al (CGN) was es tab-

l i shed under the Secretary of War to sa t i s fy the condi -

t ions of agreement wi th the IAGS. The p revious geo-

det ic bou nd ary work of the USC&GS was in tegrated in to

the new IAGS observat ions a long wi th the chains of

quadr i la tera l s observed in Guatemala (wi th the IAGS).

Wi th connect ions to the c lass ical t r i angulat ion in

Mexico , the North American Datum of 1927 (NAD 27)

was ev en t u a l l y i n t ro d u ced t o t h e R ep u b l i c o f Ho n d u ras .

Of par t i cu lar convenience was the fact that the Ocote-

peque Datum of 1935 was referenced to the same el l ip-soid ! (That was cou rtesy of the USC&GS.)

The IAGS method of comput ing chains of quadr i la ter -

a l s was the Army way of doing th ings . That way was

di f ferent f rom the USC&GS because AMS w as concern ed

wi th uni fy ing the mish-mash of Datums in pos t -war Eu-

ro p e . Th e p l an n i n g an d d es i gn fo r t h a t s p ec t acu l a r co m -

pu tat ional ch ore in Europe was u l t imately accompl i shed

wi th a conformal pro ject ion and Grid . The complexi ty

of ex i s t ing sys tems in the Americas was much s impler ,

but the Topographic Engineers of AMS were t ra ined ac-

cord ing to the Army way. That way cons i s ted of com-

put ing c lass ical t r i angulat ion on a conformal Grid . Cen-

t ra l American count r ies , wi th the except ion of Bel ize ,

are greater in eas t -wes t ex ten t than in nor th-south ex-

ten t . Therefore , the Lamber t Conformal Conic pro ject ion

was u sed as th e bas i s of a l l IAGS-developed Grid sys -

tems in Cent ra l America for t r i angulat ion computat ions

and the publ i shed Tr ig Lis t s of coord inates .

The Hond uras Lambert Conformal Grid (1946 - present)

on the Ocotepeque Datum of 1935 covers two secant

zones , Nor te and Sud. Both zones use the same Cent ra l

Meridian (lo) = 86 10 00 West of Greenwich and False

Easting of 500 km. Zone Norte has a Latitude of Origin (fo)

= 15 30 North, the False Northing = 296,917.439 meters,

and the scale factor at origin (m o) = 0.999932730. ZoneSud has a Lat i tude of Orig in (f

o) = 13 47 North, the

False North ing = 296,215.903 meters , and the scale fac-

tor at origin (mo) = 0.999951400.

In 1960, the Nicaragua-Honduras border d i spute was

final ly set t led by the Internat ional Court of Just ice (ICJ).

The determinat ion was that the 1906 Award of the King

o f S p a in s h o u l d b e ca r r i ed o u t b as ed o n t h e l i n e o f u ti

possidet is . In 1969, El Salvador and Honduras went to

war o v e r an o t h e r b o rd e r d i s p u t e . Th i s war i n v o l v ed s i x

contes ted bolsones (pockets ) of l and encompass ing a

to ta l area of 436 .9 square k i lometers , tw o i s lands

(Meanguera and El Tigre) in th e Gul f of Fonseca, and

the r ight of passage for Hondu ras to the Paci f ic Ocean

from i t s southern coas t . A peace t reaty was s igned in

1980, an arb i t ra t ion agreement was s igned in 1986, and

the en t i re mat ter was reso lved in 1993 af ter an ICJ ru l -

ing the previous year .

Mi l i t ary mapp ing of Hond uras a t 1 :50 ,000 scale

(100% coverage) and smal ler i s on the NAD 27 and uses

the UTM Grid exclu s ively. An es t imate of the t ransfor-

m a t i o n p a ram et e r s am o n g t h e ac t iv e d a t u m s i n Ho n d u -

ras can be g leaned f rom those per t inent to nearby Cos ta

Rica. For example , ( in Cos ta Rica) f rom Ocotepequ e

1935 to WGS 72: DX = 193.798 m, DY = 37.807 m, DZ

= +84.843 m. Fur th ermore, ( in Cos ta Rica) from Ocote-

peque 1935 to NAD1927: DX = +205.435 m, DY = 29.099

m , DZ= 292.202 m.

In Costa Rica, the fit of Ocotepeque Datum 1935 to

WGS 72 is better th an 3 m ; the fit of NAD27 to WGS 72is bet ter than 6 m . Considerin g the qual i ty of classical

geodetic work don e by the IAGS, the accuracy of these

identical t ransformation parameters applied in Honduras

would probably be less than double these values.

.. . . . . . . . . . .