Land Survey terms "E" and Mapping terms A complete glossary A to Z

an image of a bronze Compass with Back Azimuth

LAND SURVEY TERMS

GLOSSARY OF U.S. BUREAU OF LAND MANAGEMENT SURVEYING AND MAPPING TERMS E

Land Survey Terms, A convenient source for our clients and website visitors

E

E (Land Status Records) – East.

EC STATION – 1) Extended control station. 2) Electronic control station.

ER-55 – See later in this section.

EDM – Electronic Distance Measurement.

EDP – Electronic Data Processing.

EFF (Land Status Records) – Effective.

E.G. – An abbreviation of “exampli gratia,” which means: For the sake of an example.

EHE (Land Status Records) – Enlarged homestead entry.

ELIM (Land Status Records) – Elimination.

ENLGMT (Land Status Records) – Enlargement.

EO (Land Status Records) – Executive Order.

ES (Land Status Records) – Exchange survey.

ESLO – Eastern States Land Office. The Eastern States Land Office is in Silver Springs, Maryland. (Now designated
Eastern States Office, ESO).

ESMT (Land Status Records) – Easement.

ET AL – An abbreviation of et alii, “and others,” or et alius, “and another.”

<img class=”alignleft wp-image-9816″ src=”https://haller-blanchard.com/wp-content/uploads/2021/12/the-safe-companies-contact-us.gif” alt=”” width=”38″ height=”38″ />Please feel free to <a href=”https://haller-blanchard.com/contact-land-survey-company//”>contact us</a> about Land Survey Terms or any other questions. We are here now and ready to answer.

ETC. – The common abbreviation for “et cetera.” And others; and other things; and others of like character; and others
of like kind; and the rest; and so on; and so forth.

ET CON. – An abbreviation meaning “and husband.”

ET SEQ. – An abbreviation for et sequentes or et sequentia, “and the following.” A reference to p. 3 et seq.” means
“page number 3 and the following pages.” It is also abbreviated “et sqq.,” in some works, when the reference is to
more than one following page.

ET UX. – An abbreviation for et uxor, “and his wife.”

EXCL (Land Status Records) – Excluding, excluded.

EXP (Land Status Records) – Expire(d).

EX REL – (See word listing below).

EXT (Land Status Records) – Extended, extension, extend.

ESNA – Electrical Survey Net Adjuster.

ECCENTRICITY – 1) The amount of deviation from a center. 2) Lack of coincidence of the
several centers of
rotation, circles, and indexes of an instrument. 3) Horizontal displacement of the instrument or
signal from the
station mark at the time an observation is made. 4) A measure of the relative shape of an ellipse
or an ellipsoid.
ECCENTRICITY CORRECTION – The correction that must be applied to an observation made
from an eccentric
setup (reduction to center) or to an eccentric signal to compensate for eccentricity. See
REDUCTION TO
CENTER and SWING.
ECCENTRIC SIGNAL – A signal (target) which is not in the same vertical line with the station
which it
represents.EDGE ENHANCEMENT – Image alternation which intensifies the changes between adjacent
areas.
EDITING – Checking a map in its stages of preparation to insure correct interpretation of the
sources used and
precise reproduction.

Please feel free to contact us about Land Survey Terms or any other questions. We are here now and ready to answer.
Phone

EFFECTIVE FOCAL LENGTH (USGS) – The adjusted value of the focal length of a lens which
best fulfills the
geometric conditions of a given photogrammetric operation. In making diapositive plates, the
settings of the
printer are based on the effective focal length derived from the calibrated focal length and further
adjusted to
allow for film distortion. In photoalidade operation, the effective focal length is the setting of the
focal-length
scale which best brings a specific photograph into proper geometric perspective. The preferred
expression for
this value is “principal distance.”
ELECTRICAL SURVEY-NET ADJUSTER – A panel containing a number of adjustable
resistances and d-c
power sources for adjustment of survey data.
ELECTROMAGNETIC RADIATION – Energy propagated through space or through a material
medium as
waves or variations of electric and magnetic fields; known as radio waves, heat waves, light
waves, etc.,
depending upon frequency. Also called electromagnetic energy.
ELECTROMAGNETIC SPECTRUM – Ordered array of known electromagnetic radiations,
extended from the
shortest cosmic rays, through gamma rays, X-rays, ultraviolet radiation, visible radiation,
infrared radiation, and
including microwave and all other wavelengths of radio energy.
ELECTRONIC COLOR COMBINER – An instrument which produces false color image by
linearly combining a
few black-and-white films of the same scenes. The films are usually obtained from multiband
and time-
sequential photography. The films are put in synchronized flying spot scanners, the resulting
video signals are
linearly combined through a matrix multiplier circuit, and the three linearly combined signals
then drive the
color gun of a color TV tube. An electronic color combiner usually has greater versatility for
congruencing or
registering.
ELECTRONIC DISTANCE MEASUREMENT (EDM) – Measurement made with devices that
compare the phase difference between transmitted and returned (i.e., reflected or retransmitted)
electromagnetic waves, of
known frequency and speed, or the round-trip transit time of a pulsed signal, from which
distance is computed.

an image of a white circular Compass with Back Azimuth ELECTRONIC TRAVERSE – A traverse in which the angles are measured with a direction
theodolite and
distances with an electronic distance-measuring instrument.
ELEVATION – The vertical distance from a datum, generally mean sea level, to a point or object
on the earth’s
surface. The terms “elevation” and “altitude” have sometimes been used synonymously, but in
modern
surveying practice the term “elevation” is preferred to indicate heights on the earth’s surface
whereas “altitude”
is used to indicate the heights of points in space above the earth’s surface. See FIELD
ELEVATION, SPOT
ELEVATION and CHECKED ELEVATION.
ELEVATION METER – A mechanical or electromechanical device on wheels that measures
slope and distance
and automatically and continuously integrates their product into difference elevation.
ELEVATION TINT – The layer of color between selected contours, according to altitude. This is
a method of
obtaining a mental picture of the terrain more readily.
ELEVATION TONES – A method of accentuating the elevation expressed by contours through
the use of colors or
different tones of the same color.
ELLIPSOID – The surface generated by rotation of an ellipse about one of its axes.
ELLIPSOIDAL REFLECTOR – A mirror surface which conforms to a portion of an ellipsoid of
revolution. See
ER-55 PLOTTER.
EMISSION – With respect to electromagnetic radiation, the process by which a body emits
electromagnetic
radiation as a consequence of its temperature only.
EMULSION – A suspension of a light-sensitive material in gelatin, used for coating
photographic film, plates, or
papers.
ENCODER – A mechanism usually attached to the output of a measuring device (or
photogrammetric instrument)
which converts movements into digital information. See DIGITIZING.

ENDLAP – Progressive forward overlap of aerial photos along the line of flight.
ENGINEERING MAP – A map showing information that is essential for planning an
engineering project or
development. An engineering map is generally a large-scale map of a comparatively small area
or of a route. It
may be entirely the product of an engineering survey, or reliable information may be collected
from various
sources and delineated on a base map.

ENGINEERING SURVEY – The process of collecting and recording information for planning
an engineering
project.
ENGINEER’S LEVEL – A precision leveling instrument for establishing horizontal line of sight,
used to determine
differences of elevation.
ENHANCEMENT – Various processes and techniques designed to render optical densities of
imagery more susceptible to interpretation.91
EPHEMERIS (PLURAL EPHEMERIDES) – A tabulation of positions and related data for a
celestial body for
given dates at uniform time intervals. Also, a publication containing such data for a number of
celestial bodies.
See EMPHEMERIS*.
EPOLAR PLANE – Any plane containing the air base.
EQUALITY – Equality or equation in station numbers arises when a single point on a route
alignment has two
values. Thus station 123 + 45.6 ahead = 123 + 54.3 back.
EQUATION – 1) A statement of equality of the same point on a route survey which has two
values. 2) One of a set
of simultaneously solved equality statements which adjust for fixed conditions of length, angles,
azimuth or
position in least squares adjustment. See EQUALITY.
EQUIVALENT FOCAL LENGTH – The distance measured along the lens axis from the rear
nodal point to the
plane of best average definition over the entire field used in the aerial camera.
ER-55 PLOTTER – A stereoscopic plotting instrument of the direct-viewing, double projection
type, characterized
by the use of reduced size diapositives and an ellipsoidal-reflector illumination system in which
the light source
is at one focus of the ellipsoidal surface and the projector lens is at the other, producing optimum
illumination of
the entire image area of the diapositive. The principal distance of the projectors is 55 mm. The
commercially
manufactured version of this plotter is the Balplex.
ERROR – A class of small inaccuracies due to imperfections in equipment or techniques,
surrounding conditions, or
human limitations; not to be confused with blunders or mistakes. See ACCIDENTAL ERROR,
AVERAGE
ERROR, CONSTANT ERROR, COMPENSATING ERROR, INDEX ERROR,
INSTRUMENTAL ERROR,
PERSONAL ERROR, PROBABLE ERROR, MEAN ERROR, RANDOM ERROR, ROOT
MEAN SQUARE

ERROR, STANDARD ERROR, and SYSTEMIC ERROR.
ERROR OF CLOSURE – The amount by which a value of quantity obtained by surveying
operations fails to agree
with a fixed or theoretical value of the same quantity.
ERROR OF THE MEAN – The resultant error of the mean or average of a number of quantities.
It is the quotient
of the algebraic sum of the errors divided by the number of errors included.
ESTUARINE – Of, or pertaining to, or formed in a estuary.
ESTUARY – Drainage channel adjacent to the sea in which the tide ebbs and flows. Some
estuaries are the lower
courses of rivers or smaller streams, others are no more than drainage ways that lead seawater
into and out of
coastal swamps.

ETCHED DRAWING – A color-separation negative produced by a photomechanical process.
See
PHOTOMECHANICAL ETCHING.
ETCHING – See PHOTOMECHANICAL ETCHING.
EXPOSURE – 1) A photograph. 2) The control of light in making a photograph. Exposure-data
refers to camera
shutter and aperture settings, together with light intensity measurements, filter factors, and all
such controls of
light reaching the film.
EXPOSURE INTERVAL – The time interval between taking successive photographs.
EXPOSURE STATION – The point in space occupied by the camera lens at the time of taking
the picture.
EXTENDED CONTROL STATION – A described and monumented point established as a basis
of subsidiary
surveys, usually for Airborne Control System use. Triangle figures or electronic traverses are
used to establish
position based on higher order surveys in nearby areas.
EXTENSION OF CONTROL – Surveys executed to establish additional control from existing
control.
EXTERIOR NODE – See NODAL POINTS.
EXTERIOR PERSPECTIVE CENTER – See NODAL POINTS.

Please feel free to contact us about Land Survey Terms or any other questions. We are here now and ready to answer.
Phone

EXTRAPOLATE – To calculate the value of a function lying beyond an interval from values of
the function within
that interval. In topographic surveys extrapolation is used in estimating the elevation of a point
so situated that
the elevation cannot be interpolated between two contour lines..
EYE BASE – The distance between the pupils of the eyes of an individual; also called
interpupillary distance or
interocular distance.
EYEPIECE – The lens or combination of lenses at the observing end of one optical distance.
EYOTT – A small island arising in a river.
Please feel free to contact us about Land Survey Terms or any other questions. We are here now and ready to answer.
Phone Email us

Here is a good source for becoming a Surveyor or learning about the industry to make certain it’s the right path for your future

Glossary Search

GLOSSARY OF U.S. BUREAU OF LAND MANAGEMENT SURVEYING AND MAPPING TERMS E

Land Survey Terms, A convenient source for our clients and website visitors

E