3. ANALYZED DATA
Both optical sensor data and passive microwave sensor data
acquired from satellites were analyzed in this study. As for the
optical sensor, data from both RSI onboard FOROMSAT-2
satellite and MODIS onboard Aqua satellite were used. As for
the passive microwave sensor, data from AMSR-E onboard
Aqua satellite were used. Table 1 and 2 show the specifications
of the three sensors.
Table 1. Specifications of optical sensors
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
Sensor | Band Wavelength IFOV Swath
PAN 0.45-0.90um 2m
1 0.45-0.52um
RSI 2 0.52-0.60um 24km
8m
3 0.63-0.69um
4 0.76-0.90um
1 0.620-0.670um
MODIS 250m | 2330km
2 0.841-0.876um
Table2. Specifications of AMSR-E
Frequency IFOV Swath Incident
(polarization) angle
6.925GHz (V,H) 43X75km
10.65GHz(V,H) 9X51km
18.7GHz (V,H) 16X27k m
23.8GHz (V,H) 18X32k m 1445km 55deg
36.5GHz (V,H) 8.2X 14.4 km
89.0GHz (a) 3.7X6.5k m
89.0GHz (b) 3.5X59km
4. DIRECT MEASUREMENT OF THIN ICE
THICKNESS
In order to evaluate the possibility of estimating thin ice
thickness with optical sensors on board satellites, direct
measurements of ice thickness were performed in Saroma Lake
and Monbetsu Bay. Since the thin ices are very fragile, it is
dangerous to stand on the ice. The authors approached to the
thin ice on a small boat. The procedure of the ice thickness
measurement is shown on Figure 2. The operator makes a small
hole in the ice by using a drill (Figure 2(a)). Once the hole is
open, the operator inserts a tape measure into the hole (see
Figure 2(b)). A bar connected to the forefront of the tape
measure act as a prop, and the operator can easily measure the
ice thickness with the tape measure (See figure 2(c)). Figure 3
show the Snapshots of the ice thickness measurement in the
Saroma Lake.
ice Pg ice
(a)Open a hole in the ice with a drill. we p
(b) Insert a tape measure (c) Measure ice thickness
into the hole. with the tape measure.
Figure 2. Procedure of direct measurement of
ice thickness.
(b) Measuring the ice thickness with a ape measure
Figure 3. Direct measurement of ice thickness from a boat.