(6 
  
- 16 . 
. Earth rate and transport rate for use with a twin 
gyro platform 
. Latitude/Longitude, time, waypoint selected, distance 
to go, and time to go, for use with, for example, the 
Remote indicator, or a recorder. 
3, Integrated systems 
a. State of the art; history 
The first integrated aerial survey system based on inertial sensing 
was developed about ten years ago and was known as the "USQ-28" system. 
See (2), (9), (153,7 (46). 
Because of its high degree of sophistication and its high acquisition 
and operating costs it was far beyond the reach of civilian mapping 
agencies. The USQ-28 project was discontinued in 1972. 
Since then, inertial sensing and digital computing techniques have 
developed to such an extent that Inertial Navigation Systems became 
an of-the-shelf mass product for long-distance navigation. 
In 1974,Fokker — together with Litton and Wild — has developed the 
F27/LTN-51 Integrated Aerial Survey System and has delivered four 
of these to the government of Iran. One improved system was acquired 
by the government of Algeria (1976). See figure 6. 
Under ITC supervision,test flights have been carried out (8)swith respect 
to navigational performance, the expectations 2 could not be realized, 
The verticality tests have demonstrated a high degree of accuracy: 
order of magnitude of the precision s a modern photogrammetric analogue 
instrument. 
With respect to in-flight operation and to improvement of the INS 
computer software, suggestions have been made — by ITC and by others - 
which have led to the development of an improved integrated systems 
the Litton 2.14 ijnertially referenced LTN-72/76 Photogrammetric System 
is in a stage of being flight-tested, by ITC and elsewhere. 
b. State of the art; the latest system 
As compared to the F27/LTN-51 system, the LTN-. 72/16 Photogrammetric 
System contains a number of improvements: 
e Latitude/Longitude data entry and display precision to 0.01 min. 
« Absolute and relative navigation update capability as well as lateral 
and/or longitudinal navigation error updates. | 
. Propagation of update data into velocity and acceleration corrections 
  
9) See: "Integrated Flight and Navigation Systems" ISP Comm. I 
Invited Paper, Helsinki 1976, page 15-23. 
de tn im ttd