A NEW CONCEPT FOR AERIAL MAPPING 
2 
Map making is no small task. In the U. S. the combined efforts of the 
Army, Navy, Air Force, U. S. Geological Survey, USC&GS, Department of 
Agriculture, plus civilian contractors coordinate their talents in the 
massive efforts of accurately portraying the minute details of the earth's 
surface. 
Map detail is derived from data collected by the ground surveyors, 
who obtain horizontal and vertical control, and the aerial photographers 
who obtain the precise mapping photography. National map accuracy 
standards prescribe the details that appear on the maps published by 
cartographic agencies. 
There have been some advanced developments in the ground surveyor's 
tools. The Telurometer and Geodimeter for horizontal measurements have to 
a large extent replaced the steel tape and chain. The Ground Elevation 
Meter is being used in some areas to acquire low order leveling. 
The aerial photographer, too, has been developing a highly sophisticated 
airborne system which is the purpose of this paper. 
To start with let me briefly review our present system. Aerial 
electronic surveying (known by its coined name of Hiran) was developed as 
a first order surveying tool after World War II. The Hiran System can 
precisely measure great distances using a high altitude aircraft between 
two ground stations. Measurements can be made over short distances and up 
to distances of about 570 miles with a probable error of 12 feet. Hiran 
has accurately surveyed the Atlantic and Pacific missile ranges and made 
the historic and first precise geodetic connection between the continents 
of North America and Europe. This survey, over 2,000 miles long, between 
the North American continent and Europe achieved an accuracy of 1/314,000 
with a probable error of 34 feet. 
Mapping of an area by a combination of aerial photography and the 
aerial electronic survey technique would permit adjustment of photo positions 
(provided complete area coverage of the area is obtained) to within 25 to 
30 meters for horizontal control. This method we have called Hiran Controlled 
Photography. A terrain profile is charted by a narrow beam (1°) radar signal 
sent vertically from the aircraft which is modified with hypsometer corrections. 
This device is known as an Airborne Profile Recorder (APR). Aerial profile 
readings have been obtained and interpolated to six (6) feet in moderate 
terrain. 
Although Hiran Controlled Photography seems to be a logical answer to 
the acquisition of aerial mapping photography with horizontal control data, 
it is in many areas operationally uneconomical. The necessity for clear