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H and D curva-See characteristic curve.
hachurlng—(JCS) A melhod of representing
def upon a map or chart by shading In shorf
diifmacfad fines drawn In the direction of lhe
sbpaa.
hack chronometer-A chronometer used for
ViSUel reference, and not usually for re~rd
purposes.
halatlorr-(photography) A spreading o! a
photograpffic image beyond Its proper
boundaries, due especially to reflection from the
side of the lifrn or plate support opposite to that
on which the emulsion is coated. Particularly
noticeable in phonographs of brighl objects
egainsf a darker background.
half merk-See Indax mark.
half model—The stereoscopic model iormed
by the ovariap of two adjacenf right- or left-hand
expesures of Wnvergenl photographs.
hall aectlon-Any two quarter seclions within
a secfion which have a common boundary:
uSU.Wlyidenlifiad as the north hatl, south hall,
east hail, or west haff of a panicular section.
half tide taval—See maan tide leVel.
haltfona scraen~JCS) A series of regularly
spaced opaque lines on glass, crossing a! righl
anglea, producing transparent apertures
between Intersections, Used in a process
camera to break up a solid or continuous tone
image lnlo a pattern of small dots. Also called
croaslfne glaes screan. See also contact
acrean; halltone,
helltone—(JCS) Any photomechanical prinling
sudace or the impression therefrom In which
detail and tone values are represented by a
series of evenly spaced dots of varying size and
shape, varying in direct proportion to the
intensity Of the tones they represent. See aiso
halftone screen: mlddletone.
HaM Mar projection—A variation, by E,
Hammer in 1892, on the zenithal equal-area
(Larnberf) projection, made by doubling the
hortzomal distances along each parallel from the
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central meridian. This transforms Ihe ckular
shape of the Lamberl into an elliise, slrnilar in
appearance to a Mollweide projacfion, but with
all parallels curved except the Equator, which IS
a straight Iina.
hand leval-A hand-held tnstrumanf for
approximate levating, If cmnsisfs of a sighting
tube with a splfi fie!U of view; a trorlzomal cross
hair in one-half of the fiakj biiacfa the Image of
a spirit Iavel in tha other haft when the
inatmment is held ievel. See also Abney Iavel.
hand proof-in offset ilthography, a proof of a
plata made on a hand proof press where
oparatiins are manual for inking, dampening,
and laking the impression.
hand templet—A lemplel made by tracing
the radials from the photograph onto a
transparent plastic medium. Hand templets are
iaid out and adjusted by hand to tomr the radial
triangulation.
hand-templet pioi—See bend-templet
Irianguiatlon.
bend-tempia! triangulation—A graphical
radial triangula!’bn using any form Ot hand
templel. Also called hand-ternplet pioi.
hanging levei—A spirit Iavel so mounted that,
when in use, its Ieval tube is lower in elevation
than is points ot support,
Harbor and ApprOaCh chars (HA)—A chatl
which provides delaiied porlrayal of
navigationally useful information supportive of
maneuvering In close quaner areas to
benh/anchor, channei keeping while
emering/exiling port or navQating in close
proximity 10 dangars associated with close
shore/harlmr approach areas. Produced from
1:10,000 to ?:100,000 scale.
harbor chart-A nautical chart intended for
navigation and anchorage in harimrs and
smaller waterways.
Hardcopy Exploitation Segment
[HE/S)—Segment of DMAS DiSital Pmducfkm
System which provides sottware upgrades for
~xisting DMA photogrammetric aquipmam and
#ill delivar a new computer for triangulation.