Site log - Kwaj (Oct 1998) Flags: 1-Satellite coincidence data 2-Scan in TSDIS data 3-Scan not in TSDIS data A-Major problem (moderate to strong AP &/or widespread coverage) B-Minor problem (weak AP &/or very little coverage) ******************************************************************************* 01 Oct 98: No data due to power supply and main RCP unit failure ******************************************************************************* 02 Oct 98: No data due to power supply and main RCP unit failure ******************************************************************************* 03 Oct 98: No data due to power supply and main RCP unit failure ******************************************************************************* 04 Oct 98: Only one VOS (0508Z) on this day. Virtually all data lost due to power supply and main RCP unit failure. Scattered light/moderate showers are present at 0508Z. Data Analyzed: 0508Z only Satellite Coincidence: 0556Z(33 km), 1859Z(290 km) QC notes: No reprocessing needed ******************************************************************************************** 05 Oct 98: Very little data available on this day due to azimuth drive motor problems. During the period 0441Z to 0610Z, a large area of light to moderate showers with embedded convective cells is passing N of the radar while a smaller convective cluster is approaching the radar from the SE. Corrupt VOS: 0500-0520Z uf files placed in bad_vos directory Data Analyzed: 0441-0610Z Satellite Coincidence: 0444Z(613 km), 1923Z(553 km) QC notes: No reprocessing required. 1A !!FLAG!! 0500-0520Z: These VOSs are corrupt due to transmitter and azimuth motor problems. ******************************************************************************************** 06 Oct 98: Very little data is available on this day due to azimuth drive motor problems. During the period 0451Z to 0700Z, a large convective cluster is moving out of the radar scope to the NW, while an isolated convective cell and scattered light showers are located W of the radar near 70 km range. Data Analyzed: 0451-0700Z Satellite Coincidence: 0507Z(225 km), 1810Z(99 km) QC notes: 0451-0700Z: Light/moderate second trip echo SE and SW of radar at far range. ----> Partially Corrected - most second trip echo removed (see flags) 2B !!FLAG!! 0600Z: Minor second trip echo at far range SW of radar cannot be completely removed without also removing too much real precip echo. 2B !!FLAG!! 0630Z: Minor second trip echo at far range SW of radar cannot be completely removed without also removing too much real precip echo. ******************************************************************************************** 07 Oct 98: Only surveillance scans on this day due to azimuth drive motor problems. ******************************************************************************************** 08 Oct 98: Widespread showers and convection develop rapidly and move into the radar FOV after 04Z. This activity covers most of the scope in a broken pattern. Several large convective clusters pass near the radar, with ~45 dBZ echos passing over the radar during the 15Z hour. Large areas of light to moderate rain with embedded convective cells and lines pass from E to W across the entire scope. The activity rapidly diminishes in coverage after 20Z. Near the end of the day, an additional convective cluster moves into the radar FOV from the NE, while pockets of light to moderate rain exit the scope to the West. Data Analyzed: 0101-1940Z 2050-2357Z Satellite Coincidence: 0419Z(425 km), 1722Z(100 km) QC notes: 2B,3B !!FLAG!! 0101-0300Z: Light/moderate intensity second trip echo SE of radar at far range. ----> Partially Corrected - some second trip echo removed. A few minor patches are still present and cannot be removed without removing too much precip. A few light showers were also removed in this QC process. 0612Z: Intense clutter speck along atoll edge N of radar. ----> Corrected - clutter removed 0754-0803Z: Moderate clutter specks along atoll edge N of radar. ----> Corrected - clutter specks removed 0906-1132Z: Light second trip echo SE and SW of radar at far range. Also, some intense clutter specks near the radar. ----> Corrected - second trip echo removed. A few light showers were also removed in this QC process. A few minor patches of second trip echo still remain, but they are at the 150 km range and of light intensity and are not flagged. Several VOSs must be flagged due to embedded clutter specks. 3A !!FLAG!! 1111-1132Z: Intense clutter specks surrounding radar are embedded in precip and cannot be removed. This problem is mainly noticeable in the second tilt images. 0928-0937Z: Intense clutter specks (some embedded in precip) N of radar. ----> Partially Corrected - specks removed from 0928 VOS (see flag) 2A !!FLAG!! 0937Z: Intense clutter embedded in light precip near radar. 1153-1242Z: Light/moderate intensity second trip echo at far range at various azimuths around radar. ----> Corrected - second trip echo removed. A few light showers were also removed in this QC process. 1202Z: Intense clutter embedded in precip along edge of atoll. ----> Corrected - clutter removed at the expense of also removing a light shower near the radar. 1334-2357Z: Scattered light/moderate second trip echo mainly at far range and at various azimuth directions around radar. Also, some intense clutter specks near the radar. ----> Partially Corrected - some second trip echo removed. A few minor patches of second trip echo remain but they are at far range and light intensity and are not flagged. A large patch of spurious echo remains in-tact SW of the radar near the end of the day and therefore a large time period must be flagged. A few light showers were removed during this QC process 2A,3A !!FLAG!! 1334-1356Z: Intense clutter specks embedded in light precip near radar. 2A,3A !!FLAG!! 1426-1537Z: Intense clutter specks embedded in light precip near radar. This is especially noticeable in the second tilt images. 1A !!FLAG!! 1638-1718Z: Intense clutter embedded in precip along edge of atoll. 3B !!FLAG!! 1840Z: Minor second trip spike at far range E of radar cannot be completely removed without also removing too much precip. 3A !!FLAG!! 1849Z: Intense clutter speck embedded in light precip very close to the radar in the second tilt image. 2A !!FLAG!! 1932Z: Intense clutter speck along atoll edge N of radar cannot be removed due to close proximity of precip. 3A !!FLAG!! 2140Z: Moderate clutter speck SW of radar cannot be removed. 2A,3A,3B !!FLAG!! 2050-2254Z: Light to moderate second trip echo SW of radar cannot be completely removed due to presence of precip. A large patch of second trip echo remains. ******************************************************************************************** 09 Oct 98: Significant precipitation covers the scope for the majority of the day. A large and rather intense area of convection moves into the radar FOV from the NE as the day begins, while a seperate smaller convective cluster develops just North of the radar. By 04Z, the northern half of the scope is covered with mainly moderate rain with embedded convection. Heavy precip moves directly over the radar site while the precip becomes oriented in an E-W pattern. A slight break in the action occurs during the 11Z hour, but new convection rapidly develops S of the radar after 14Z. By 18Z, a large area of moderate rain with convective cells surrounding the edges builds northward and pushes over the radar from the SW. This activity increases in coverage, but decreases in intensity as it slowly moves toward the NW. After 2310Z, the volume scans appear to be corrupt as most precip vanishes from the scope in an abrupt mannor. Unfortunately, no good TRMM overpasses on this day. Data Analyzed: 0007-2340Z Satellite Coincidence: 0307Z(236 km), 1609Z(568 km) QC notes: 0007-2310Z: Light/moderate second trip echo at mid/far range throughout the entire day at various azimuths around radar. ----> Partially Corrected - some second trip echo could not be removed due to presence of precip (see flags). A few light showers were removed as a result of this qc reprocessing. Some minor second trip echo patches near 150 km range were not removed or flagged. Blocky type appearance of some echo areas are the result of the QC algorithm removing only part of the second trip echo and leaving other spurious echo in-tact surrounding precip cores. 2B !!FLAG!! 0233Z: small patch of moderate second trip echo remains SW of radar 2B,3B !!FLAG!! 1307-1517Z: small patches of light/moderate second trip echo remains SW and NE of radar. 1B,2B,3B !!FLAG!! 1640-1801Z: small patches of light/moderate second trip echo remains W of radar - blocky type appearance is due to algorithm not being able to remove all second trip echo surrounding real precip echo. --------------------------------------------------------------------------------- 0039-0427Z: Intense clutter specks along atoll edge N of radar ----> Partially Corrected - some clutter could not be removed because it is embedded in precip or in very close proximity to precip. 1A,2A,3A !!FLAG!! 0100-0242Z: Intense clutter embedded in precip near Atoll edge N of radar 1A !!FLAG!! 0334Z: Intense clutter in close proximity to precip. 2A,3A !!FLAG!! 0802-0942Z: Intense clutter specks embedded in precip along atoll edges North of the radar. 1144Z: Moderate clutter specks NW of radar. ----> Corrected - speck removed 1236-1245Z: Intense clutter specks along atoll edge N of radar ----> Partially Corrected - speck removed from 1236 VOS 3B !!FLAG!! 1245Z: Intense clutter speck could not be removed without also removing significant precip. 1416-1517Z: Intense clutter specks along atoll edge N of radar ----> Partially Corrected (see flags) 3A !!FLAG!! 1416Z: Intense clutter speck N of radar cannot be removed. 2A,3A !!FLAG!! 1456-1517Z: Moderate/intense clutter specks N and NW of radar cannot be removed due to proximity of precip. 1618-1658Z: Intense clutter specks along atoll edge N of radar ----> Partially Corrected - most clutter removed 1A !!FLAG!! 1658Z: Intense clutter at close range to radar cannot be removed due to proximity of precip. 2A,3A !!FLAG!! 1750-1811Z: Intense clutter specks embedded in precip along atoll edges North of the radar. 2A,3A !!FLAG!! 2043-2240Z: Intense clutter specks embedded in light precip along atoll edges North of the radar. 2A,3A !!FLAG!! 2320-2340Z: These volume scans are corrupt due to failing azimuth motor, and have been placed in a bad_files directory. ******************************************************************************************** 10 Oct 98: Scattered light to moderate showers and convection are present on this day. A large convective cell develops N of the radar near 0250Z. This cell then splits into two smaller cells which then dissipate after 04Z. Limited data is available due to azimuth motor problems. Data Analyzed: 0011-1030Z (only surv scans after 1030Z) Satellite Coincidence: 0330Z(624 km), 1633Z(288 km) QC notes: 0011-1030Z: Second trip echo of light/moderate intensity contaminates every VOS. Most spurious echo is at far range. ----> Partially Corrected - most second trip echo removed (see flags) A few light showers were removed as a result of QC 2B !!FLAG!! 0011Z: Minor second trip echo at mid-range W of radar could not be removed without also removing significant precip 2B,3B !!FLAG!! 0410-0431Z: Minor second trip echo at mid and far range could not be removed. 0110-0231Z: Moderate to intense clutter specks along Atoll edge ----> Partially Corrected - some clutter specks removed 2A,3A !!FLAG!! 0121-0220Z: Moderate to intense clutter specks remain due to proximity of precip 0421Z: Intense clutter speck NW of radar. ----> Corrected - speck significantly reduced in intensity 0450-0551Z: Clutter of varying intensities mainly close to the radar. The 0500Z VOS contains clutter to the NW at far range. ----> Corrected - clutter either removed or significantly reduced in intensity 0830-1030Z: Clutter of varying intensities close to the radar. ----> Corrected - clutter specks removed ******************************************************************************************** 11 Oct - 26 Oct 98: No volume scan data during this period due to azimuth motor problems/replacement. Radar was not operating 981012, 981014-981020. Surv. scans only 981011, 981013, 981021-981026 ******************************************************************************************** 27 Oct 98: Mainly scattered light showers during the limited data available. A small patch of moderate rain with a possible convective cell just barely pushes into the radar FOV at far range during the 23Z hour. Data Analyzed: 2102-2357Z Satellite Coincidence: 0717Z(317 km), 1701Z(638 km) QC notes: 2232-2310Z: Moderate second trip echo SW of radar at mid/far range plus occasional moderate clutter specks near radar. ----> Corrected - spurious echo removed 2338Z: Moderate clutter specks N of radar along atoll edge ----> Corrected - spurious echo removed ******************************************************************************************** 28 Oct 98: Significant precipitation and widespread convection throughout the day. Only scattered light to moderate showers dot the scope early in the day, but the activity rapidly increases in coverage and intensity after 05Z. Several thin bands of moderate showers and embedded convection pass over the radar. After 16Z, a large convective cluster moves into the radar FOV from the SE. Several thin E-W oriented bands of showers with heavier embedded convection are also present. By 19Z, two large convective clusters cover the southern half of the scope while strong scattered convection prevails in the northern half. Near the end of the day, a large moderate intensity rain shield with large embedded convective regions is located S and W of the radar while scattered convection and lighter showers prevail over the radar and to the North. A very active day at Kwajalein. Data Analyzed: 0007-2352Z Satellite Coincidence: 0741Z(529 km), 1725Z(201 km) QC notes: 0007-2352Z: Light to moderate second trip echo is present at mid/far range throughout the entire day. Some moderate to intense clutter specks (some embedded in precip) are mainly N of radar along the edge of the atoll - mainly whenever precip moves over or close to the radar. Overall, second trip echo is the main problem, and is quite difficult to remove completely, especially when the spurious echo is embedded in real echo. ----> Partially Corrected - Some minor second trip patches near 150 km range still exist and are not flagged. Some larger and higher reflectivity second trip echo patches also remain and the affected VOSs are flagged below. Also, some embedded clutter causes several more time periods to be flagged. Some light (10 dBZ) showers were removed during this QC process. There appears to be no way to avoid this compromise. 2B,3B !!FLAG!! 0520-0536Z: Small light/moderate patch of second trip echo SW of the radar (far range) cannot be completely removed. 2A !!FLAG!! 0536Z: Intense clutter embedded in precip along atoll edge near radar. 1B,2B,3B !!FLAG!! 0606-0724Z: Small light/moderate patches of second trip echo S and SE of the radar (mid/far range) cannot be completely removed. 2B,3B !!FLAG!! 1028-1407Z: Small light/moderate patches of second trip echo S and SE of the radar (mid/far range) cannot be completely removed. 1A !!FLAG!! 1723Z: Intense clutter specks embedded in precip near radar. 2A !!FLAG!! 1801Z: Intense clutter speck in close proximity to precip near radar 3A !!FLAG!! 1839Z: Intense clutter specks embedded in precip near radar. 2A,3A !!FLAG!! 2245-2352Z: Intense clutter specks embedded in precip near radar. ******************************************************************************************** 29 Oct 98: Widespread convection and large areas of moderate/heavy rain cover the scope for a large portion of the day. The activity diminishes in coverage from near 06Z to 14Z, but then rapidly increases. Several convective clusters (with 50 dBZ+ echos) move directly over or very close to the radar. Data Analyzed: 0000-2352Z Satellite Coincidence: 0628Z(122 km), 1613Z(454 km) QC notes: 0000-2352Z: Widespread light to moderate second trip echo at various azimuths and ranges from the radar. Some of this second trip echo is embedded in or bordering on real precip echo. This makes effective QC very difficult. The extent of the spurious echo is evident when viewing the VR images. The QC algorithm has modest success in removing some of the second trip, which results in the appearance of holes in the echo. Several periods must be flagged. Some light showers (5-10 dBZ) have been removed as a result of QC attempts. Also, ground clutter specks aligned along the atoll edge are a constant source of QC problems. Most of these specks cannot be removed when precip moves over or near the atoll. Several periods are flagged due to this embedded clutter. 3A !!FLAG!! 0152Z: VOS is corrupt - UF file placed in bad_files directory 2A,3A !!FLAG!! 0000-0130Z: Intense clutter specks embedded in precip near radar. 2A !!FLAG!! 0230Z: Intense clutter specks embedded in precip near radar. 3A !!FLAG!! 0345Z: Intense clutter along atoll edge cannot be removed due to proximity of precip. 2A,3A !!FLAG!! 0430-0530Z: Intense clutter specks embedded in precip near radar. 3A !!FLAG!! 0552Z: Intense clutter specks embedded in precip near radar (2nd tilt) 1A !!FLAG!! 0622-0700Z: Intense clutter specks embedded in precip near radar. 2A,3A,3B !!FLAG!! 0753-0830Z: Light/moderate second trip echo NW of radar at far range. Also, 0753 and 0800 VOS contain intense clutter specks embedded in precip near radar. Spurious echo cannot be removed without removing precip echo. 3A !!FLAG!! 1015Z: Intense clutter specks embedded in precip along atoll edge (2nd tilt) 2A !!FLAG!! 1101Z: Intense clutter speck due N of radar which cannot be removed without also removing significant real precip echo. 2A,3A !!FLAG!! 1422-1522Z: Intense clutter specks embedded in precip near radar. 3A !!FLAG!! 1645Z: Intense clutter specks embedded in precip near radar (2nd tilt) 2A,3A !!FLAG!! 1822-1845Z: Intense clutter specks embedded in precip near radar. 2A,3A !!FLAG!! 1923-1944Z: Intense clutter specks embedded in precip near radar. 2A,3A,3B !!FLAG!! 2045-2344Z: Light/moderate second trip echo W & NW of radar at mid/far range. Spurious echo cannot be removed without removing precip echo. Second trip is embedded in real precip echo and is most easily distinguished from real echo by using the VR images as reference. 2115Z VOS - also contains intense clutter speck near radar. 2144Z VOS - " " 2200-2214Z - " " ******************************************************************************************** 30 Oct 98: Widespread showers and convection early in the day slowly diminishes in intensity and coverage. By 09Z, only scattered activity remains and these smaller scattered patches of showers and somewhat isolated convective cells continue through the end of the day. After 17Z, the showers and cells become a little more numerous in the southern half of the scope. Data Analyzed: 0000-2354Z Satellite Coincidence: 0652Z(709 km), 1636Z(392 km) QC notes: 0014-0352Z: Minor second trip echo SE of radar at far range. Some intense clutter specks are also present. ----> Partially Corrected - most second trip echo was removed but many VOSs contain embedded clutter specks which could not be removed (see flags). A few light showers were removed during this QC process which results in a blocky type appearance of some echos. 3A !!FLAG!! 0022Z: Intense clutter specks embedded in precip near radar. 3A !!FLAG!! 0144Z: Intense clutter specks embedded in precip near radar. 2A,3A !!FLAG!! 0452-0600Z: Intense clutter specks embedded in precip along atoll edge 0623Z: Minor second trip echo SW of radar at far range. ----> Corrected - spurious echo removed 0815Z: Intense clutter near radar. ----> Corrected - clutter removed 2A,3A !!FLAG!! 0831-0853Z: Intense clutter specks embedded in precip along atoll edge 1454-1927Z: Intense clutter specks along atoll edge (some specks embedded in precip) ----> Partially Corrected - some clutter removed (see flags) 3A !!FLAG!! 1718-1725Z: Intense clutter embedded in precip near radar 2316Z: Moderate clutter specks near radar. ----> Corrected - specks removed ******************************************************************************************** 31 Oct 98: Scattered to isolated light showers dot the scope from 00-09Z. After 09Z, acivity increases in converage and intensity and continues through the remainder of the day. There are no large scale areas of heavy rain. The pattern continues to be many lines and widespread coverage of small pockets of rain with embedded convective-like cells. A few larger convective clusters rotate in from the S and SE toward the end of the day. Data Analyzed: 0002-2353Z Satellite Coincidence: 0539Z(69 km), 1524Z(266 km) QC notes: 0545Z: Intense clutter specks N of radar near atoll edge. ----> Corrected 0623Z: Solar interference spike SW (sunset) ----> Corrected - spike removed 0631Z: Intense clutter speck near radar ----> Corrected 3A !!FLAG!! 0653Z: Intense clutter speck near radar cannot be removed due to proximity of precip 0746Z: Moderate clutter speck NW near 150 km range ----> Corrected 0854Z: Intense clutter speck near radar ----> Corrected 2A,3A !!FLAG!! 0947-1125Z: Intense clutter specks near radar (most embedded in precip) cannot be removed without also removing significant precip echo 1234-1458Z: Intense clutter specks near radar (some embedded in precip) ----> Partially Corrected - some specks could not be removed (see flags) 2A,3A !!FLAG!! 1304-1319Z: Intense clutter embedded in precip near radar. 1A,2A,3A !!FLAG!! 1428-1458Z: Intense clutter embedded in precip near radar. 1A !!FLAG!! 1505-1536Z: Corrupt VOSs - no reflectivity - UF files placed in 'bad_files' directory 1558-1636Z: Intense clutter specks near radar (some embedded in precip) ----> Partially corrected - some specks could not be removed (see flag) 2A !!FLAG!! 1636Z: Intense clutter embedded in precip near radar 1551-1806Z: Light to moderate seoncd trip echo E, S and SE at mid/far range. ----> Corrected - spurious echo removed 2A,3A !!FLAG!! 2050-2353Z: Intense clutter specks embedded in precip near radar. ********************************************************************************************