China Second Institute of Oceanography
Profiling Drifters

Table of Contents

  1. Introduction
  2. Automatic data processing & web-page generation
  3. Reliability statistics
  4. Argos Data Telemetry
  5. Contact Information
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Introduction

Welcome to the unofficial web site for the China Second Institute of Oceanography profiling drifters.

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 May 01 00:01 GMT 2001 to Dec 17 09:38 GMT 2011.
Group Size Profiles Executed Profiles Expected Reliability (%)
APEX260 20 2411 5183 46.5
APF8 20 2411 5183 46.5
Alkaline(DP) 6 667 1535 43.5
Lithium 6 1102 1187 92.8
Total 20 2411 5183 46.5

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.

China Second Institute of Oceanography Profiling Drifter ARGOS Receipt Statistics
As of 08:36 GMT on Mar 30, 2010 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
0801 192 48 25.0% 10 54% 100 74 74% 26 26% 55 72% 20 28%
0806 93 6 6.5% 10 64% 114 93 81% 21 19% 74 79% 19 21%
1140 57 0 0.0% 15 64% 229 180 79% 48 21% 145 80% 35 20%
1141 77 0 0.0% 21 68% 272 232 86% 40 14% 185 80% 48 20%
1142 53 0 0.0% 12 60% 130 106 86% 24 14% 86 71% 20 29%
1143 93 1 1.1% 15 54% 147 122 83% 25 17% 93 65% 29 35%
1144 72 0 0.0% 15 64% 211 165 78% 46 22% 135 81% 30 19%
1145 13 0 0.0% 20 69% 290 243 84% 47 16% 202 83% 42 17%
1539 131 4 3.1% 11 64% 185 131 77% 54 23% 109 82% 23 18%
1540 126 1 0.8% 12 66% 169 132 79% 37 21% 111 84% 21 16%
1541 162 2 1.2% 11 60% 169 127 76% 41 24% 101 79% 27 21%
1542 111 14 12.6% 12 49% 178 116 68% 62 32% 82 71% 33 29%
1543 52 4 7.7% 10 54% 160 112 71% 48 29% 83 75% 28 25%
1544 91 7 7.7% 13 51% 178 123 70% 55 30% 89 72% 34 28%
1636 135 1 0.7% 18 56% 246 181 74% 65 26% 138 76% 43 24%
2748 138 16 11.6% 18 35% 230 141 62% 90 38% 81 57% 60 43%
2749 138 2 1.4% 18 42% 245 157 65% 87 35% 102 64% 56 36%
2750 136 3 2.2% 18 48% 236 157 68% 80 32% 112 71% 45 29%
2751 136 1 0.7% 18 55% 283 205 73% 78 27% 156 76% 49 24%
2752 86 1 1.2% 19 54% 261 189 73% 72 27% 142 75% 47 25%
Ensemble Average: 4.2% 15 57% 202 149 75% 52 25% 114 75% 35 25%
Standard Deviation: 6.3% 4 9% 57 45 7% 21 7% 38 7% 13 7%


Contact Information: Please note that the data and material on this web site are the property of the China Second Institute of Oceanography. Questions concerning the information available here can be addressed to Dr. Jianping Xu, (email: sioxu@zgb.com.cn).

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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