Off-line orthophoto printer
The off-line orthophoto printer system (Sca-
rano and Jeric, 1973) uses an OMI optical /me-
canical scannerprinter, a Bendix BX-272
control computer, and magnetic tape and tele-
type units. It operates independently (in the
physical sense) of any plotter, although it needs
elevation data generated by an AS-11B-1 analy-
tical plotter, and one photograph of the stereo-
pair from which the elevation data were compt-
led. Either a rectified photograph, an ortho-
photograph, or an orthophoto stereomate can
be produced. Inputs include not only vertical
and convergent frame photographs, but also
non-conventional imagery such as the conver-
gent optical bar used on the Apollo flights. The
system has reproduced 72 line pairs per milli-
metre highcontrast targets and has provided ve-
ry good quality continuous-tone imagery. Input
scanning at 10 mm/s allows production of 9:
x 9 - inch orthophotos in 50-60 minutes.
Digital cartography
The Advanced Cartographic System (AGS) is
a total system of hardware and software to com-
pile or build an entire map digitally (Sippel,
1975; Premer, 1974; Hall 1974). The input
is usually analog (model, photo, graphic line
map, etc.) which is converted to digital. The
manipulation step allows for such operations as
scale change, projection change, and resolution
change. The third step is the output, usually a
cartographic product.
The AS-11B is used to digitize a photogram-
metric model while a plot is produced simulta-
neously. A point on a contour is plotted when
either a distance or a coordinate changes by a
specified step value.
A single panoramic photograph can also be
used directly where rectification is performed
mathematically. First, control is used to resect
the camera position, the neach ray is intersected
with given DTM data to obtain the rectified
position. If the input is in graphic form, it is
converted to digital form using either a linea-
rizing scheme, or a rasterscanning scheme such
as the Floating Arm Graphic Recorder
(FAGR). Processing routines include least-
squares fitting to control and editing and up-
dating. The latter usually employs interactive
editing stations and a high-speed profiling plot-
ter.
[4
A program called SHADLEN (Mirkay, 1974)
uses a D'TM matrix of elevations as input and
generates a shaded-relief map with photo-head
plotters, point and line plotters, and raster
plotters.
Automated hydrographic charting
For hydrographic applications, an Automa-
ted Cartographic System is being developed to
provide complete digital chart production
(Dixon, 1974). The source material is in analog
form of charts, aerial photographs, and hydro-
graphic survey smooth sheets. Once digitized,
the data are stored in geographic files by fea-
ture type and recorded at a resolution commen-
surate with the largest scale product. When a
specific product is desired, the data from the fi-
les are input to a digital compilation device
that can adjust scale and projection and produ-
ce a tape. The tape can be the final digital pro-
duct or used to produce a conventional pro-
duct.
Digital image analysis
Gray-tone data from day and night thermal-
IR sensors were used in a computer analysis for
three land-use types: water, vegetation, and
construction material (Turinetti and Mintzer,
1973). Tones were quantized with a 10-gray-
tone stepwedge. In the experiment 40 percent
of targets were uniquely and correctly identi-
fied from only thermal-IR density information.
This result leads to the conclusion that of the
six pattern elements in photointerpretation, to-
ne alone can be used to classify land uses. Fur-
thermore, computer automation of the proce-
dure frees the photo-interpreter for more com-
plex tasks.
An interactive system for automatic classifi-
cation of image patterns (Turinetti and Hoff-
man, 1974) is composed of a PDP 11/20 com-
puter connected with a Spatial Data System 8oo
Image Analyzer (Tektronix 4010 display). The
input can be photo data (TV vidicon), digital
data, or analog line-scan data with A/D conver-
sion.
Another concept proposes a Visualizer to aid
in providing interpretive and electronic-ima-
gery data (Stringham, 1974). The concept is in-
tended to be more effective and make smaller
demands on manpower. The device could be
carried in the user's pocket and receive as input
