Data Set ID:

Double Rain Gauge Network, Iowa, Version 1

This data set includes rainfall data from 25 sites in Iowa, centered on the Iowa City Municipal Airport.

This is the most recent version of these data.

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Data: Data integrity verified

Documentation: Key metadata and links to supporting documentation available

User Support: Assistance with data access and basic data usage

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Data Format(s):
  • ASCII Text
Spatial Coverage:
N: 41.75, 
S: 41.5, 
E: -91.5, 
W: -91.75
Spatial Resolution:Not SpecifiedSensor(s):ORG
Temporal Coverage:
  • 18 June 2002 to 13 November 2003
Temporal ResolutionNot specifiedMetadata XML:View Metadata Record
Data Contributor(s):Witold Krajewski

Geographic Coverage

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As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Krajewski, W. F. 2004. Double Rain Gauge Network, Iowa, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

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Detailed Data Description


Data files are ASCII text files.

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File and Directory Structure

Files are named after the study sites. For example, SITE12.dat.

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File Size

File sizes range from 2.69 MB to 3.51 MB.

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Total volume of data files is 78.72 MB.

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Spatial Coverage

Southernmost Latitude: 41.5° N
Northernmost Latitude: 41.75° N
Westernmost Longitude: 91.75° W
Easternmost Longitude: 91.5° W

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Temporal Coverage

18 June 2002 through 13 November 2003. Different data files cover different time periods. The table below shows the start and end dates for each site.

Site number Start date End date
1 8/13/02 11/12/03
2 8/11/02 11/12/03
3 09/19/02 11/12/03
4 8/11/02 11/12/03
5 8/11/02 11/12/03
6 8/11/02 11/12/03
7 8/11/02 11/12/03
8 8/11/02 11/12/03
9 8/11/02 11/12/03
10 6/18/02 11/12/03
11 6/20/02 11/12/03
12 8/18/02 11/20/03
13 8/15/02 11/11/03
14 8/12/02 11/12/03
15 9/14/02 11/13/03
16 8/12/02 11/12/03
17 8/15/02 11/13/03
18 8/15/02 11/12/03
19 8/15/02 9/26/03
20 8/14/02 11/12/03
21 6/21/02 11/12/03
22 6/21/02 11/12/03
23 6/18/02 11/12/03
24 8/18/02 11/12/03
25 10/17/02 11/13/03

Temporal Resolution

Data files contain readings in five minute intervals.

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Parameter or Variable

Parameter Description

Rainfall is measured by two tipping bucket rain gauges. Each data file consists of three columns:

  1. Date (yyymmdd)
  2. Time (hh:mm:ss) UTC
  3. recorded rain rate in mm

Unit of Measurement

Rainfall amount (in mm) from tipping bucket gauge.

Parameter Source

The network consists of 25 dual tipping bucket rain gauge platforms.

Sample Data Record

The following sample is taken from the "SITE04.dat" file.

20020811  15:15:00	0.00
20020811  15:20:00	12.43
20020811  15:25:00	5.69
20020811  15:30:00	0.43
20020811  15:35:00	0.00
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Error Sources

Raw data were taken in one-minute intervals, and processed into five-minute rain accumulations. Although such short time scale accumulations are associated with significant random error, providing data on a five-minute basis provides flexibility in selecting the time interval for analysis. This is particularly important for evaluation of remote sensing products. The random error of the tipping bucket rain gauge data decreases with time accumulation scale. It is negligible for scales longer than about 15 minutes.

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Quality Assessment

The investigators guarantee quality between 1 April and 13 November, 2003.

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Software and Tools

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Data Acquisition and Processing

Derivation Techniques and Algorithms

Processing Steps

After quality control of the raw data from the tipping buckets, investigators used the tip interpolation method (Ciach 2002) to calculate rain rate. The rain rate values in the third column of the data files are the average of the two tipping-bucket rain gauges on the platform. Because of the way a tipping-bucket operates, data were recorded data only when the buckets tipped (when they contained moisture).

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Sensor or Instrument Description

The network consists of 25 dual tipping-bucket rain gauge platforms. Please see IIHR- Hydroscience and Engineering to learn more.

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References and Related Publications

Contacts and Acknowledgments

Witold F. Krajewski
IIHR-Hydroscience & Engineering
University of Iowa


Investigators and others who worked with this data include Anton Kruger, Ralph Ferraro, and Grzegorz J. Ciach of the IIHR-Hydroscience & Engineering department of the University of Iowa, and Jeffrey McCollum of the University of Maryland. This research was done under NASA Grant Number NAG5-11969.

Document Information


February 2004

No technical references available for this data set.

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