SPN1 DNI Firmware- Use of the DNI function4 of 8 5/4/2016www.delta-t.co.ukFigure 2 Illustration indicating sign conventions used for entering Latitude, Longitude and time zone in the SPN1DNI calculationsGPS time and positionFor simplicity, we recommend that you take the latitude, longitude and GPS time from a GPS receiver,and set the SPN1 time zone to 00:00. These will then be correct wherever in the world you are.- LONGITUDE ++165+12 -12+11180+150+10+9+135+8+120+7+105+6+90+5+75+4+60+3+45+2+30+1+1500-1-15-2-3-30-45-4-60-5-75-6-7-90-105-120-135-150-165-8-9-10-11- LATITUDE +- Time Zone +

About DNI: What is it and why should I care

How do I calculate DNI if my SPN1 is horizontal

GPS time and position

SPN1 electrical connections

RS232 Commands for obtaining DNI

SPN1 DNI Command usage

Conversion of GPS sentences for use with SPN1

Delta-T SPN1 Technical Note

Introduction

Construction

Accessories

System overview

Power considerations

Use with a data logger

ground connections

Delta-T data logger connections

Use with a PC or serial device

Accuracy and errors

Technical reference

SPN1 spectral response

SPN1 cosine response

Routine maintenance

Calibration procedure and traceability

Warranty and service

Service and spares

Problems

Appendix A: Design and test summary

Calculation of outputs

Test results

Appendix B: RS232 commands

test mode

Glossary

SPN1