Japan 4
surveyed by means of plane table. Even in this field, however, the plane
table method will gradually be replaced by aerial photogrammetry.
Terrestrial photogrammetry is open to large scale mapping of dam sites,
wherewith the best possible result is expected. It may be worthy to note
that trial surveying of 1:500 maps by aerial photogrammetry is now carried
on.
b. Application to Forestry Surveying.
Aerial photogrammetry is applied on a grand scale to forestry surveying.
First, it was applied to the surveying of private forests, the area amounting
to more than 100,000 km? in 5 years. The forestry maps thus obtained show
features of mountain ridges and valley lines, pass points for compass survey
ing and so forth. Forestry Board tried to make maps by means of stereoplott-
ing instruments and to classify wood species. The results were satisfactory
and they are intending to apply photogrammetric survey to forestry mana-
gement on broader scale.
e. Cadastral surveying
In our country, less accurate provissional cadastral surveying was per-
formed about 70 years ago.
The National Land Survey Law was issued in 1951, and scientific cadast-
ral surveying has been put forward in reference to the Law.
The survey was first executed by means of plane table. The years' experi
ences however awake the demand for application of aerial photogrammetry
in this field of work. According to the Law, the cadastral map is to be plotted
by Ist or 2nd order instrument with the aero-photos taken on the scale
1:6,000-1:8,000. The maps, especially those of cultivated area, should be made
on the scale 1:1,000 or 1:500.
5. Application to Non Topographic Fields
Among a number of examples, those referred to below are notable. K.
Hidaka and his collaborators studied the forms of ocean waver by means
of stereo-photogrammetry. The investigation has been extended in this line
by the members of the Hydrographic Institute.
In addition, Technical Research Laboratory of National Rail Road of
Japan has advanced the study on the height of shore waves by using
specially designed instrument, the results of which will be helpful to the
harbour construction.
6. Aerial Photo-interpretation
On the occasion of compiling 1:50,000 Land Use Maps, the method of
aerial photo interpretation was applied with successful results. The com-
pilation of the Land Use Map was commenced in 1952, and 212 sheets have
been completed by the Geographical Survey Instiute.
Another trial was also made on application to the survey of distu rbed