Kashima Space Research Center
Communications Research Laboratory
893-1 Hirai, Kashima, Ibaraki 314, Japan
Generally speaking, a technical development is closely connected with scientific progress, and vice versa. We summarize this relation as follows.
The other one is a ``spread promotion'' loop. Being different from the previous one, this type of loop aims to reduce cost rather than to increase accuracy, in order to permit wide dissemination of the system in the VLBI community. Miniaturization of the system can also be a goal for portability. Even though accuracy of measurements is sacrificed, widely distributed VLBI terminals will produce new observational data which bring a new insights in science.
The former one, pursuing an accuracy improvement, can be divided into two types
of terminal which are planned or almost developed at the Communications Research
Laboratory (CRL) (Fig.2).
In addition to persuing accuracy we should be concerned about the distribution of terminals. If the price of VLBI terminal goes down with total performance being kept as accurate as current one, terminals will be easily distributed widely. Furthermore if it becomes compact in size, we will be able to bring it easily anywhere in the world.
CRL should proceed with both types of development if possible.
Nakajima, J., Current status of the gigabit VLBI recorder system, VLBI TDC News
CRL, No.9, pp.17-18, 1996.