REMOTE DATA TRANSMISION SYSTEM A Major Qualifying Project: submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE and performed at SRI INTERNATIONAL in partial fulfillment of the requirements for the Degree of Bachelor of Science by ____________________________ Eric Hall ____________________________ Peter Kaineg ____________________________ Amanda Quigley ____________________________ Eric Young Date: March 4, 2006 Approved: ______________________________ Professor John Orr, Major Advisor Advisors: Roy Stehle Todd Valentic Andrew Young Table of Contents Abstract............................................................................................................................viii Executive Summary........................................................................................................... ix 1 Introduction................................................................................................................. 1 2 Background................................................................................................................. 2 2.1 Scientific Background......................................................................................... 2 2.1.2 Why Transmit Data in Real Time? ............................................................. 2 2.1.3 Why Deploy Arctic Sensing Systems? ....................................................... 2 2.1.4 Existing Systems for Real Time Data Transmission .................................. 3 2.1.5 A New Approach to Remote Data Transmission........................................ 4 2.2 Alaskan Weather................................................................................................. 5 2.3 Collecting Data ................................................................................................... 8 2.3.2 System Description ..................................................................................... 9 2.3.3 Peripherals................................................................................................... 9 2.3.4 Software .................................................................................................... 10 2.3.5 Short Cut (SCWin).................................................................................... 10 2.3.6 CRBasic .................................................................................................... 11 2.4 Sending Data..................................................................................................... 11 2.4.2 Iridium Satellite Data Network................................................................. 12 2.4.3 Data Transport Network ........................................................................... 13 2.4.4 Python Programming Language ............................................................... 14 2.5 Power System.................................................................................................... 15 2.5.2 Battery....................................................................................................... 15 2.5.3 Power Generation...................................................................................... 16 2.5.4 Charge Controller...................................................................................... 18 3 Specifications............................................................................................................ 19 3.1 Communication Specifications ......................................................................... 19 3.2 Power Specifications......................................................................................... 19 3.3 Physical Specifications ..................................................................................... 20 4 Design Choices ......................................................................................................... 21 4.1 Quantity of Data & Frequency of Data Transmission ...................................... 21 4.2 Short Burst Data vs. Dial Up ............................................................................ 23 4.2.2.1 Short Burst Data Service........................................................................... 23 4.2.2.2 Dial-Up Service ........................................................................................ 24 4.3 Processing ......................................................................................................... 26 4.4 Data Transfer .................................................................................................... 27 5 Design Documentation.............................................................................................. 29 5.1 Power System.................................................................................................... 29 5.1.2 Battery....................................................................................................... 30 5.1.3 Solar Panel ................................................................................................ 30 5.1.4 Charge Controller...................................................................................... 30 5.2 Switching Circuit .............................................................................................. 31 5.2.2 High level Design ..................................................................................... 31 ii 5.2.3 Circuit Operation ...................................................................................... 33 5.2.4 Part Selection ............................................................................................ 33 5.2.5 Control Port............................................................................................... 33 5.2.6 Assembly................................................................................................... 34 5.3 CR1000 Code.................................................................................................... 34 5.3.2 Top Level System ..................................................................................... 34 5.3.3 Transmit Data............................................................................................ 36 5.3.4 Establish Connection ................................................................................ 37 5.3.5 Data Out.................................................................................................... 39 5.3.6 Accept New Transmit Period.................................................................... 42 5.4 Data Management Code.................................................................................... 43 5.4.2 Receiving the Data.................................................................................... 44 5.4.3 Preparing Data for Viewing...................................................................... 49 5.4.4 Website ..................................................................................................... 54 6 Testing and Results................................................................................................... 59 6.1 CR1000 Code Tests .......................................................................................... 59 6.1.2 Hello World .............................................................................................. 59 6.1.3 Serial In..................................................................................................... 60 6.1.4 Data Collection ......................................................................................... 62 6.1.5 Send Data.................................................................................................. 63 6.1.6 Control Port Time ..................................................................................... 65 6.1.7 Iridium Hello World ................................................................................. 67 6.2 Python Code Tests ............................................................................................ 68 6.2.2 Computer to Computer ............................................................................. 68 6.3 Full System Tests.............................................................................................. 69 6.3.2 Reliability & Frequency............................................................................ 69 6.3.3 NO CARRIER .......................................................................................... 70 6.3.4 Data Transfer Rate .................................................................................... 71 6.3.5 Full System Reliability ............................................................................. 73 6.4 Energy Testing.................................................................................................. 74 6.4.2 Communications Energy Consumption.................................................... 74 6.4.3 Datalogger Energy Consumption.............................................................. 76 6.4.4 Battery State of Charge Expectation......................................................... 78 7 Recommendations for Future Work.......................................................................... 82 7.1 Universal Datalogger Communications............................................................ 82 7.2 Dial up and SBD communications.................................................................... 82 7.3 Mobile Terminated Calling............................................................................... 83 7.4 Camera for Datalogger.....................................................................................