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
Return to Root Page

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 Nov 08 09:36 GMT 2009.
Group Size Profiles Executed Profiles Expected Reliability (%)
APEX260 20 1994 3720 53.6
APF8 20 1994 3720 53.6
Alkaline(DP) 6 667 1104 60.4
Lithium 6 685 732 93.6
Total 20 1994 3720 53.6

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.

China Second Institute of Oceanography Profiling Drifter ARGOS Receipt Statistics
As of 09:36 GMT on Nov 08, 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
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 121 1 0.8% 18 57% 244 181 74% 63 26% 139 77% 42 23%
2748 124 15 12.1% 18 36% 228 140 62% 88 38% 80 57% 59 43%
2749 124 2 1.6% 18 43% 244 158 65% 86 35% 103 65% 55 35%
2750 123 3 2.4% 17 48% 235 156 68% 79 32% 112 72% 44 28%
2751 123 2 1.6% 18 56% 279 203 73% 76 27% 155 76% 48 24%
2752 76 1 1.3% 19 54% 257 185 72% 72 28% 139 75% 46 25%
Ensemble Average: 4.3% 15 57% 201 149 75% 52 25% 114 75% 35 25%
Standard Deviation: 6.3% 4 9% 56 45 7% 21 7% 38 7% 12 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.

Root Page

Vistior Number: