# Presentation: 167371

## USGS Instantaneous Data Archive

**COE/NWS/USGS Annual Water Control Meeting**
**November 14, 2006**

**Robert R. Holmes, Jr., PhD, P.E.**
**Director, USGS Illinois Water Science Center**

## What are USGS “Instantaneous Data”

**What are USGS “Instantaneous Data”**

**Historically, USGS has primarily published daily data (mean, max, min)**
**“****Instantaneous Data” – 5 minute to 60 minute data used to compute the daily values**
**Instantaneous data are stored in the WSC NWIS database from mid-1980s, but generally not “cleaned up” to publication standards**

## What is the USGS Instantaneous Data Archive (IDA)

**What is the USGS Instantaneous Data Archive (IDA)**

**On-line publicly-accessible repository of available instantaneous data corresponding to the period of published daily data.**

## IDA Challenges

**IDA Challenges**

**Numerous instantaneous data types (discharge, stage, water quality, precipitation, etc)**
**Various storage formats (NWIS, spreadsheets, paper tape, etc)**
**Instantaneous data not cleaned up to daily value “publication standards” (backwater, instrumentation problems, spikes, etc)**
**Multiple data sources (primary and backup recorders, instrumentation updates, etc)**
**Very time consuming and expensive to clean-up historical data (one site with 15-min data for 20 years has over 700,000 data points)**

## IDA Initial System Design

**IDA Initial System Design**

**Discharge data only**
**Use historical data already in NWIS database (generally from mid-1980s)**
**Data quality assured using automated and manual checks, but not processed and corrected to similar “publication standards” as daily values**

## IDA Discharge Data Automated QA Tests

**IDA Discharge Data Automated QA Tests**

**Compute daily mean value from instantaneous data, compare to published daily mean, assign QA code based on comparison.**

**Code 0 – near zero values**
**Code 1 – matches within 1 percent**
**Code 2 – matches from 1 to 5 percent**
**Code 3 – matches from 5 to 10 percent**

## IDA versus NWISWeb

**IDA versus NWISWeb**

**NWISWeb – real-time instantaneous data, most recent 30 days**
**IDA – instantaneous data corresponding to period of published daily data**
**Potential gap up to 18 months between data in NWISWeb and data in IDA**

## IDA Current Status

**IDA populated with data from eight Water Science Centers (Arizona, Arkansas, Georgia, Idaho, Illinois, Kansas, Maine, North Carolina, Texas)**
**All USGS Water Science Centers requested to add data**
**Internal Web access only**

## IDA Web Interface

**Search by:**
**Geographic Area**
**Site Number**

## Example IDA Site Page 

**Example IDA Site Page **

**Period of available data**
**Number of data values**
**View summary report**
**Retrieve data**

## Example IDA Site Summary Report

**Example IDA Site Summary Report**

**Number of days per month with data, grouped by accuracy code and water year**

## Example IDA Data Retrieval

**Example IDA Data Retrieval**

**Lists date retrieved**
**Header has  field definitions**
**Data values**
**QA codes**

## IDA Plans

**Short Term**
**Populate with discharge data from all WSCs**
**Open to COE and NWS after additional WSCs have added data**
**Open to the Public**
**Long Term**
**Add other data types**
**Close 18 month gap between IDA and NWISWeb**