During IMCET '98, eleven observation flights were conducted and nine
simultaneous rain observations with the PR were achieved. Each flight condition
is shown in Table 3.1. CAMPR-D observation parameters are summarized in Table
3.2.
Table 3.1 CAMPR-D observation flights during IMCET '98
CAMPR-D Observation Flight
Simultaneous Rain Observation with the PR
No.
Date
Objective
Flight Area
Case
TRMM Granule
Time (JST)
Rain Type etc.
1
May 17
radar test flight
Around Nagoya
2
May 23
Ferry flight #1
From Nagoya to Tanegashima
(i)
2779
11:47
Very weak and Small
3
May 23
Ferry flight #2
From Tanegashima to Miyakojima
4
May 25
TRMM overpass #1
Around Ishigakijima
(ii)
2811
12:35
Small Area
5
May 26
TRMM overpass #2
Around Okinawa
(iii)
2826
11:23
Large Area Stratiform
6
May 27
TRMM overpass #3
Around Ishigakijima
(iv)
2842
11:46
Convective
7
May 28
TRMM overpass #4
Around Okinawa
(v)
2857
10:34
Very Small Single Cell
8
May 30
TRMM overpass #5
Around Miyakojima
(vi)
2888
9:46
Convective Narrow Rain Band
9
May 31
Simultaneous observation with “MIRAI*”
Around Miyakojima
10
June 25
TRMM overpass #6
Around Shikoku
(vii)
3303
17:14
Large Area
11
June 26
TRMM overpass #7
Around Nagoya
(viii)
3317
14:25
Small and Weak
(ix)
3318
16:02
Single Cell
* "MIRAI" is the Japan Marine Science & Technology Center's
Oceanographic Research Vessel which has 3-dimensional doppler radar.
Both CAMPR flight trajectory and the PR rain echo pattern at each TRMM
overpass are shown in Figure 3.1. The horizontal distribution of corrected Z factor (2A25) at 1.5 km
Table 3.2 CAMPR-D Observation Parameters at the TRMM Overpass
Case
Date
TRMM granule
CAMPR
Mode
Antenna Scanning
Altitude
Data File Name
Time (JST)
(i)
May 23
2779
Polarization
-30 to +30
8164 m
0523_09
11:37:57-11:54:57
(ii)
May 25
2811
Dual Beam
-30 to +30
8666 m
0525_05
12:26:04-12:40:55
(iii)
May 26
2826
Dual Beam
-30 to +30
9148 m
0526_08
11:01:15-11:44:14
(iv)
May 27
2842
Polarization
-20 to +85
9160 m
0527_04
11:36:20-11:51:35
(v)
May 28
2857
Dual Beam
-45 to +45
6245 m
0528_04
10:28:17-10:51:35
(vi)
May 30
2888
Dual Beam
-20 to +85
2908 m
0530_08
09:31:02-09:56:16
(vii)
June 25
3303
Dual Beam
-45 to +45
9509 m
0625_05
17:01:02-17:18:27
(viii)
June 26
3317
Dual Beam
-20 to +85
9213 m
0626_06
14:21:02-14:25:52
(ix)
June 26
3318
Dual Beam
-25 to +80
7534 m
0626_15
15:54:25-16:03:51
Altitude is displayed with the GMS infrared cloud image. During IMCET'98 (May
23-May30), the weather conditions were not good for simultaneous rainfall
observation between the PR and CAMPR-D. At three cases: (i) May 23, (ii) May 25,
and (v) May 28, rainfall area was very sparse. In the case (iii) May 26,
stratiform rain area was uniformly extended over the East China sea to the west
of Okinawa island. At both (iv) May 27 and (vi) May 30 cases, convective rain
was observed. During IMCET'98-nagoya (June 25,26), two observation flights were
conducted and three simultaneous observations were succeeded. In the case (vii)
June 25, large rainfall area was observed over land at the north part of
Shikoku. Both (viii) and (ix) June 26 cases were sporadic rain cell.
3.2 Comparison of vertical cross-section
In the Figure 3.2, vertical cross-section of the PR 1C21 uncorrected Z factor
(Figure 3.2 (a)) and CAMPR-D received power (Figure 3.2 (b)) are shown. Though
the airplane installed CAMPR-D took about 20 minutes to fly along the TRMM track
direction, both echo patterns correspond well with each other.
3.3 Comparison of horizontal cross-section
In the Figures 3.3-1, 3.3-2 and 3.4, horizontal cross-section of the PR and
CAMPR-D are shown. These images indicate that good correspondence exists between
the PR rain echo pattern and that of CAMPR-D. However, the observation area of
CAMPR-D is very limited compared with that of the PR, it is not so effective to
compare both images directly. Some statistical approach, such as the Contoured
Frequency by Altitude Diagrams (CFADs) may be suitable.