Korean Meteorological Administration Profiling Drifters

Korean Meteorological Administration
Profiling Drifters

Introduction
Automatic data processing & web-page generation
Reliability statistics
Argos Data Telemetry
Contact Information

Introduction

Welcome to the unofficial web site for the Korean Meteorological Administration profiling drifter study.

Automatic data processing, data distribution, & web-pages generation

This web site contains thousands of dynamic objects that must be updated as new data become available. Examples include postscript files, jpeg images, tables, HTML files, hydrographic profile data, and data distribution services. These objects are automatically generated or maintained in quasi-real-time by an extensible system of autonomous software. Consequently, maintaining this web site requires no regular manual intervention.

Reliability Statistics

The reliability of the floats can be measured in terms of the number of profiles expected during a specified time period as compared to the number actually executed. These statistics are presented in the following table (updated daily).

Profiling Drifter Reliability

Profiler Reliability Statistics for the period from Jan 01 00:01 GMT 2000 to Nov 24 20:06 GMT 2009.
Group	Size	Profiles Executed	Profiles Expected	Reliability (%)
APEX260	37	2765	11261	24.6
APF8	37	2765	11261	24.6
Total	37	2765	11261	24.6

Argos Data Telemetry

The data are recovered from the floats via the Argos system. These floats spend 7 to 8 hours transmitting on the surface with one message transmitted every 46 to 54 seconds. This means that each float transmits from 470 to 530 messages for each profile. Most of these transmissions are lost because no satellite happens to be overhead. In fact, telemetry statistics below show that only 7 to 10 percent of these messages are transmitted when a satellite is overhead. Some statistics have wider appeal and we have collected several of them in the table below (updated daily). All of these statistics were computed on a per-profile basis.

Float Id: A unique 3 digit identifier assigned to each float.
Number of Profiles: The number of profiles the float has executed so far.
Incomplete Profiles: The number of profiles that have an incomplete Argos message set. This condition results in a missing segment of data in the profile plots. The accompanying percentage gives the ratio of the Incomplete Profiles to the Number of Profiles.
Satellite Passes: The average number of times that a satellite passed overhead while the float was on the surface.
Messages Expected: This is the average number of messages that should have been received when satellites were overhead. If two or more satellites are overhead simultaneously then each transmission was multiply-counted. The number of messages expected for a given satellite pass is determined from the Argos data stream by counting the number of messages received and adding the number of messages missing. Due to averaging and rounding effects, these entries in the table below may not add up exactly.
Messages Received: This is the average number of messages that were actually received by satellites (without regard to the CRC check). The accompanying percentage gives the average ratio of the messages received to the messages expected.
Messages Missing: This is the average number of messages that were transmitted while a given satellite was overhead but that were not received by the satellite. These are detected in the Argos data stream by gaps in time and message number. The accompanying percentage gives the average ratio of the messages missing to the messages expected.
Good Messages: This is the average number of messages received that passed the CRC check. The accompanying percentage gives the average ratio of the good messages to the messages received.
Bad Messages: This is the average number of messages received that failed the CRC check. The accompanying percentage gives the average ratio of the bad messages to the messages received.
Telemetric Efficiency: This measures the average rate of successful transmission when satellites are overhead. It is the average ratio of the number of good messages to the number of messages expected.

Korean Meteorological Administration Profiling Drifter ARGOS Receipt Statistics

As of 20:07 GMT on Nov 24, 2009				Average Per-Profile Statistics for ARGOS Data Telemetry
Float Id	Profiles Executed	Incomplete Profiles		Satellite Passes	Telemetric Efficiency	Messages Expected	Messages Received		Messages Missing		Good Messages		Bad Messages
0616	30	1	3.3%	12	52%	102	75	74%	27	26%	53	70%	22	30%
0686	9	0	0.0%	9	59%	90	70	78%	20	22%	53	76%	17	24%
0689	79	4	5.1%	12	56%	169	123	72%	45	28%	98	78%	25	22%
0691	115	3	2.6%	11	64%	148	117	79%	31	21%	95	81%	22	19%
0692	83	13	15.7%	11	55%	144	104	71%	40	29%	82	77%	22	23%
0693	1	0	0.0%	7	76%	59	59	100%	0	0%	45	76%	14	24%
0694	1	0	0.0%	4	79%	39	39	100%	0	0%	31	79%	8	21%
0695	1	0	0.0%	4	67%	30	30	100%	0	0%	20	67%	10	33%
0719	2	1	50.0%	6	53%	68	44	76%	24	24%	30	68%	14	32%
0933	101	0	0.0%	15	61%	202	158	78%	44	22%	124	78%	34	22%
0934	64	0	0.0%	17	65%	220	179	81%	42	19%	144	80%	35	20%
0935	216	5	2.3%	14	51%	204	138	72%	66	28%	99	70%	39	30%
0936	255	14	5.5%	11	49%	155	110	71%	45	29%	77	68%	33	32%
0937	14	0	0.0%	11	59%	152	112	74%	40	26%	89	80%	22	20%
0938	66	1	1.5%	18	64%	265	205	80%	61	20%	165	80%	40	20%
0939	160	0	0.0%	14	68%	210	169	81%	41	19%	142	84%	27	16%
0940	1	0	0.0%	7	54%	26	26	100%	0	0%	14	54%	12	46%
0941	96	2	2.1%	15	60%	247	169	77%	78	23%	133	78%	35	22%
0942	24	0	0.0%	14	68%	210	169	81%	41	19%	141	83%	28	17%
0943	45	0	0.0%	21	72%	212	191	90%	21	10%	154	80%	37	20%
0944	102	1	1.0%	14	59%	213	161	76%	51	24%	127	78%	34	22%
0945	36	0	0.0%	17	71%	236	199	85%	37	15%	168	84%	31	16%
0946	63	1	1.6%	17	69%	169	142	86%	27	14%	116	80%	26	20%
0947	4	0	0.0%	13	68%	160	126	82%	34	18%	105	83%	21	17%
1457	52	21	40.4%	5	54%	89	61	72%	27	28%	46	75%	15	25%
1458	56	24	42.9%	6	56%	87	62	75%	25	25%	45	74%	17	26%
1459	130	5	3.8%	10	68%	80	68	86%	11	14%	54	78%	15	22%
1460	72	20	27.8%	6	60%	96	70	75%	27	25%	54	78%	16	22%
1461	94	31	33.0%	8	55%	121	77	74%	44	26%	57	74%	20	26%
1462	59	25	42.4%	5	59%	76	55	76%	22	24%	43	78%	12	22%
1463	112	26	23.2%	8	53%	121	80	70%	41	30%	59	75%	21	25%
1464	2	0	0.0%	4	84%	50	48	96%	2	4%	42	88%	6	12%
1465	119	12	10.1%	6	51%	42	33	83%	10	17%	23	63%	10	37%
1466	13	0	0.0%	4	75%	63	55	87%	8	13%	47	86%	8	14%
1467	122	18	14.8%	8	54%	109	79	75%	29	25%	56	71%	24	29%
1468	149	28	18.8%	7	50%	102	70	71%	32	29%	48	69%	22	31%
1469	159	36	22.6%	6	50%	86	59	72%	28	28%	40	69%	18	31%
1470	1	0	0.0%	1	70%	10	10	100%	0	0%	7	70%	3	30%
1471	133	4	3.0%	6	62%	90	71	80%	19	20%	55	78%	16	22%


Ensemble Average:			9.6%	11	58%	146	108	76%	37	24%	83	75%	25	25%
Standard Deviation:			14.6%	5	14%	109	58	11%	84	11%	49	11%	13	11%

Contact Information: Please note that the data and material on this web site are the property of the Korean Meteorological Administration. Questions concerning the information available here can be addressed to Dr. Jae-Cheol Nam, (email: jcnam@metri.re.kr).

This web site was developed and is maintained by Dana Swift (email:swift@ocean.washington.edu) of the University of Washington, Seattle, Washington.

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Korean Meteorological AdministrationProfiling Drifters

Table of Contents

Introduction

Automatic data processing, data distribution, & web-pages generation

Reliability Statistics

Argos Data Telemetry

Korean Meteorological Administration
Profiling Drifters