Interim Guidance for Developing 

Global Positioning System 

Data Collection Standard 

Operating Procedures 

and 

Quality Assurance Project Plans

R E S E A R C H A N D D E V E L O P M E N T

Interim Guidance for Developing 

Global Positioning System 

Data Collection Standard 

Operating Procedures 

and 

Quality Assurance Project Plans

EPA Report 

Revision 1.0 

Project Lead 

George M. Brilis, Chair

Geospatial Quality Council 

U.S. Environmental Protection Agency 

Office of Research and Development 

National Exposure Research Laboratory 

Environmental Sciences Division 

P.O. Box 93478 

Las Vegas, NV 89193-3478 

EPA/600/R-08/020 

February 2008 

www.epa.gov 

231odc07

U.S. Environmental Protection Agency 

Office of Research and Development 

Washington, DC 20460

Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official 

Agency policy. Mention of trade names and commercial products does not constitute endorsement or 

recommendation for use. 
ii
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Authorship and Contributors 

Primary Author 

Noel Kohl, Region 5 

Contributing Authors 

George M. Brilis, EPA, ORD

Carrie Middleton, EPA, NEIC 

Rollin Strohman, California Polytechnic University 

Nita Tallent-Halsell, EPA, ORD 

 

Contributing Editors 

Tyrone R. Smith, county of San Bernardino, CA 

Lynne Petterson, EPA, ORD 

Jeffrey C. Worthington, EPA, OEI 

Reviewed and Edited by

Andrew Lowe, 

Field Data Collection Subgroup 

EPA GIS Work Group 

Peer Reviewers 

 Kevin Kirby David Hansen John G. Lyon 

 EPA, OEI Bureau of Reclamation EPA, ORD 

 Richard Egg John T. Lin Jerry Johnston 

 Texas State Soil & Water EPA, ORD EPA, OEI 

 Conservation Board 
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Table of Contents 

Authorship and Contributors........................................................................................................................iii 

Primary Author ...............................................................................................................................iii 

Contributing Authors ......................................................................................................................iii 

Contributing Editors .......................................................................................................................iii 

Peer Reviewers ...............................................................................................................................iii 

Acknowledgments........................................................................................................................................ix 

Background..................................................................................................................................................xi 

Introduction................................................................................................................................................xiii 

Purpose and Intended Audience....................................................................................................xiii 

Document Structure and Use ........................................................................................................xiv 

Section 1 Standard Operating Procedure for Global Positioning System Data Collection

.........................................................................................................................................xiv 

Section 2 GPS Quality Assurance Project Plan (QAPP) Requirements.................xiv 

Section 3 GPS Quality Assurance Project Plan (QAPP) Template ........................xiv 

Section 1 Standard Operating Procedure for Global Positioning System Data Collection 

Purpose.............................................................................................................................................3 

Background......................................................................................................................................3 

Planning and Implementing a GPS Survey......................................................................................3 

Pre-Survey Planning ...........................................................................................................3

Define Objectives of the Survey .........................................................................................4 

Define Project Area ............................................................................................................ 4 

Determine Observation Window and Schedule of Operations ...........................................5 

Establish Control Configuration .........................................................................................5 

Select Survey Locations......................................................................................................6 

Coordinate Pre-Survey Plans ..............................................................................................6

Equipment Testing and Logistics........................................................................................7 

Prepare the Quality Assurance Project Plan .......................................................................8 

Survey Execution................................................................................................................8 

Establishing a Schedule of Operations ...............................................................................8 

Pre-Survey: The Day Before...............................................................................................8 

Pre-data Collection: Establishing a Base Station(s)............................................................8 

Data Collection: Performing the GPS Survey.....................................................................8 

Data Assessment, Processing and Validation .....................................................................9

Data Transfer ......................................................................................................................9 
vi

Table of Contents (Cont.) 

Data Assessment and Initial Processing .............................................................................9 

Computation........................................................................................................................9

Data Conversion to GIS...................................................................................................10 

Metadata Documentation and Reporting ..........................................................................10

References......................................................................................................................................10 

Attachment 1..................................................................................................................................13 

Section 2 GPS Quality Assurance Project Plan (QAPP) Requirements 

Purpose..........................................................................................................................................................1 

Background...................................................................................................................................................1 

EPA QA Policy..........................................................................................................................................1 

EPA QA/QC Requirements and Guidelines ..............................................................................................1 

Uniform Federal Policy for QA Project Plans...........................................................................................1 

Spatial QA Project Plan Considerations .......................................................................................................2 

Components of a QA Project Plan.............................................................................................................2 

Group A. Project Management ..................................................................................................................2 

Group B. Data Generation and Acquisition...............................................................................................2 

Group C. Assessment and Oversight .........................................................................................................2 

Group D. Data Validation and Usability ...................................................................................................2 

Graded Approach.......................................................................................................................................3 

Category I ..................................................................................................................................................3 

Category II.................................................................................................................................................4 

Category III ...............................................................................................................................................4 

Category IV ...............................................................................................................................................4 

Generic vs. Project-Specific QA Project Plans..........................................................................................4 

Enforcement Considerations......................................................................................................................4 

QA Project Plans – Quality Management Plans – GPS Template ................................................................5 

Division and Office Quality Management Plans ......................................................................................5 

Use of the GPS QAPP Template ...............................................................................................................5 
vii

Table of Contents (Cont.)

Section 3 GPS Quality Assurance Project Plan (QAPP) Template 

Title and Approval Sheet ..............................................................................................................................1 

Table of Contents..........................................................................................................................................3 

A. Project Management ................................................................................................................................5 

1. Project Distribution List...............................................................................................................5 

2. Project/Task Organization ...........................................................................................................5 

3. Problem Definition/Background..................................................................................................5 

4. Project/Task Description..............................................................................................................6 

5. Quality Objectives and Survey Measurement Performance Criteria ...........................................6 

6. Training/Certification ..................................................................................................................7 

7. Documentation and Records........................................................................................................7 

B. Measurement Data Acquisition................................................................................................................7 

1. Sampling Process Design.............................................................................................................7 

2. Sampling and Image Acquisition Methods..................................................................................8 

3. Sample Handling and Custody.....................................................................................................8 

4. Analytical Methods......................................................................................................................8 

5. Quality Control ............................................................................................................................8 

6. Instrument/Equipment Testing, Inspection, and Maintenance Records.......................................8 

7. Instrument Calibration and Frequency.........................................................................................8 

8. Inspection/Acceptance Specifications for Supplies and Consumables........................................8 

9. Nondirect Measurements .............................................................................................................8 

10. Data Management ......................................................................................................................9 

C. Assessment/Oversight ............................................................................................................................10 

1. Assessment and Response Actions ............................................................................................10 

2. Reports to Management .............................................................................................................10 

D. Data Validation and Usability................................................................................................................11 

1. Data Review, Validation, and Verification Criteria...................................................................11 

2. Verification and Validation Methods.........................................................................................11 

3. Reconciliation with User Requirements .................................................................................... 11 
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Acknowledgments 

The geospatial community appreciates the tremendous contribution of the primary author, Mr. Noel Kohl, 

EPA Region 5. The U.S. Global Positioning System (GPS) is gaining increasing importance as geospatial 

science and technology are further developed and seamlessly integrated into not only environmental 

applications, but in our daily lives. This guidance is a landmark on the path to harmonized GPS data 

collection activities for environmental applications. 

It is noteworthy that in creating the core of this document, Mr. Kohl referenced previous products of the 

EPA Geospatial Quality Council. This is a positive reflection of the dedication, efforts, and forwardthinking of the individuals who have contributed to the efforts of the EPA Geospatial Quality Council. 

Manuscript reviewers provide the critical function of peer review. Their comments, suggestions, and 

recommendations for this document are greatly appreciated. 
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Background 

Since its formation in 1998, the U.S. EPA Geospatial Quality Council (GQC) developed products that 

provide Quality Assurance (QA) guidance for the development, use, and products of geospatial activities 

and research. At least two GQC’s products became the foundation for EPA geospatial data policy. These 

include: 

• EPA Guidance for Geospatial Data Quality Assurance Project Plans (Peer Review Draft), 

EPA/600/R-01/062, and 

• Global Positioning Systems: Technical Implementation Guidance, (GPS-TIG) Revision 2.0, July 

2006, EPA/600/R-03/001.

As demonstrated, the GQC can be credited for establishing the foundation of QA in EPA geospatial 

activities. 

With a QA foundation in place, the GQC now focuses on improving administrative efficiency. The 

approach being taken is to develop Standard Operating Procedures (SOPs) that can be tailored and 

adapted by organizational entities in the EPA and its extended partners. The administrative benefits of 

developing these SOPs include, at a minimum: 

• Reduction of time scientists spend writing a full Quality Assurance Project Plan (QAPP) 

• Approach taken by the various organizational entities in the EPA is, at the core, harmonized. 

This adds the value of increased confidence and interoperability in each other’s products.

On February 27, 2004, the Office of Environmental Information (OEI)/Office of Information Collection 

(OIC) distributed the GPS-TIG to the EPA. The release memo states: 

“This document also provides guidance for the development of consistent Standard Operating 

Procedures for the collection of locational data. The ultimate vision is to have universally 

comparable locational data by collecting GPS data in a consistent manner.” 

Mr. Kohl used that guidance to develop an exemplary Region 5 SOP and QAPP template. The Region 5 

documents serve as the core of this GQC product. 
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Introduction

Purpose and Intended Audience

The United States Environmental Protection Agency (U.S. EPA, hereinafter referred to as the “Agency” 

or the “EPA” for the purposes of this document) Geospatial Quality Council developed this document to 

harmonize the process of collecting, editing, and exporting spatial data of known quality using the Global 

Positioning System (GPS). Each organizational entity may adopt this document as the core of their 

Standard Operation Procedures (SOP) manual on GPS data collection procedures. 

The intended audience for this document includes U.S. EPA staff, contractors, and grantees who will be: 

 1. Participating in GPS survey planning, 

 2. Conducting a GPS survey, 

 3. Maintaining and lending GPS equipment, and 

 4. Processing data sets collected in the field and converting them to various file formats for use in a 

Geographic Information System (GIS) data base. 

This document may also serve as a reference guide for Agency staff who will be using GPS equipment 

and the individual(s) responsible for the maintenance of this equipment. Training on the proper use of the 

GPS equipment may be required of Agency staff, contractors, and grantees prior to its use. Training will 

be provided either by Agency staff or through vendor contracts. 

This document does not attempt to detail the specific functions of the various receivers because the rapid 

advancements in GPS technology would necessitate constant, diligent updates to this document. The 

mention of trade names or commercial products does not constitute endorsement or recommendation for 

use. 

Four important points must be understood by the readers and users of this document: 

 1. The level of effort and detail should be based on a common sense, “graded approach” that 

establishes QA and quality control QC requirements commensurate with the importance of the 

work, the available resources, and the unique needs of the organization. 

 2. Because this guidance is intended to be a living document, recommendations to include technology 

that is currently being developed, and new technology that has not yet become an integral part of 

the EPA’s toolbox, were not included in the document. When the new technology has become an 

integral part of the EPA’s geospatial repertoire, this document will be updated by its custodian 

(OEI). 

 3. This document is not intended to “micromanage” the GPS community; therefore, only 

“suggestions” to define limits were included. In addition, attempts were made to keep the 

document “user-friendly” by keeping the volume of the document to a minimum. 

 4. Users should check the appropriate references for the latest updates prior to the initiation of work. 
xiv

Document Structure & Use 

This document is divided into three sections. When initially used while targeting a specific project, 

implementation of the guidance contained herein will result in an organizational entity creating: 

• A Standard Operating Procedure (SOP), 

• A GPS Quality Assurance Project Plan (QAPP) for the targeted project, and 

• A GPS Quality Assurance Project Plan (QAPP) Template that is tailored for the organizational 

entity to create additional GPS QAPPs.

Section 1 

Standard Operating Procedure for Global Positioning System Data Collection

This SOP may be tailored, and then adopted by each organizational entity after wordsmithing and 

obtaining signatures for approval. The SOP is consistent with the EPA Guidance for Preparing Standard 

Operating Procedures, EPA/600/B-07/001, April 2007. When revising this section for their use, each 

organizational entity should ensure that the “document control notation” in the upper right-hand corner 

accurately reflects the organization’s information. When finalized and approved, the SOP should be 

distributed throughout the organizational entity. This section also introduces the concept of QA 

Categories to facilitate implementation of the graded approach. 

In the EPA, GPS is most frequently used for surveys. Therefore, this focus of this SOP is for GPS 

surveys. However, it can be edited by the user for the purposes of processing and reporting GPS data 

sets. 

Section 2 

GPS Quality Assurance Project Plan (QAPP) Requirements 

 

This section, and the QAPP template in the next section, is a derivative of EPA Guidance for Geospatial 

Data Quality Assurance Project Plans (QA/G-5G), March 2003. It was condensed and tailored to address 

GPS data collection activities. This section also contains a table of examples where the graded approach 

can be applied. A section has been added on Enforcement Considerations, including chain-of-custody. In 

addition, QA Categories are further defined. 

The user should refer to the EPA Guidance for Geospatial Data Quality Assurance Project Plans (QA/G5G), March 2003, for definitions, more detailed guidance, clarifications, etc. 

Section 3 

GPS Quality Assurance Project Plan (QAPP) Template 

The template in this section was designed to facilitate writing a GPS QAPP. The template was 

designed for point data collections which are the most common surveys. Surveys to collect 

polygon or line data would require additional modifications in the template. Text in blue font 

should be replaced with appropriate text in regular font.
Section 1

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Standard Operating Procedure for 

Global Positioning System Data Collection 
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Table of Contents 

Purpose..........................................................................................................................................................3 

Background...................................................................................................................................................3 

Planning and Implementing a GPS Survey...................................................................................................3 

Pre-Survey Planning ..................................................................................................................................3 

Define Objectives of the Survey................................................................................................................4 

Define Project Area ...................................................................................................................................4 

Determine Observation Window and Schedule of Operations..................................................................5 

Establish Control Configuration ................................................................................................................5 

Select Survey Locations ............................................................................................................................6 

Coordinate Pre-Survey Plans.....................................................................................................................6

Equipment Testing and Logistics ..............................................................................................................7 

Prepare the Quality Assurance Project Plan ..............................................................................................8 

Survey Execution.......................................................................................................................................8 

Establishing a Schedule of Operations ......................................................................................................8 

Pre-Survey: The Day Before .....................................................................................................................8 

Pre-data Collection: Establishing a Base Station(s) ..................................................................................8 

Data Collection: Performing the GPS Survey ...........................................................................................8 

Data Assessment, Processing and Validation............................................................................................9

Data Transfer .............................................................................................................................................9 

Data Assessment and Initial Processing ....................................................................................................9 

Computation ..............................................................................................................................................9

Data Conversion to GIS..........................................................................................................................10 

Metadata Documentation and Reporting.................................................................................................10

References...................................................................................................................................................10 

Attachment 1...............................................................................................................................................13 
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U.S. Environmental Protection Agency 

Geospatial Quality Council

DRAFT 

STANDARD OPERATING PROCEDURE 

Title: GLOBAL POSITIONING SYSTEM (GPS) DATA COLLECTION

Effective Date: Number: 

Author Date:

Author (Source &/or Steward)

Name: 

Organization: 

Date: 

Editor

Name: 

Title: 

Approval 

Name: 

Title: 

Signature: Date: 

Concurrence1

Name: 

Title: 

Signature: Date: 

 

1

Optional – typically used by project officers for review by QA Manager 
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Global Positioning System (GPS) 

Standard Operating Procedures 

1. Purpose 

This SOP provides basic steps to guide the process of collecting, editing, and reporting accurate 

spatial data using Global Positioning System (GPS) technology. The intended audience of this 

document includes all personnel involved in planning and conducting GPS surveys, as well as 

processing and reporting GPS data sets. This SOP is not intended as a detailed user manual for 

specific brands of GPS receivers, operating systems or software applications. 

2. Background 

The U.S. Global Positioning System is based on the Navigation Satellite Time and Ranging 

(NAVSTAR) system operated by the Department of Defense (DOD). The system was initiated in 

1977 with the launch of the first constellation of satellites orbiting approximately 12,500 miles above 

Earth. There are at least four satellites in each of six fixed orbiting planes. This constellation provides 

GPS users with four to eight visible satellite signals at all times from any point on Earth. Its initial use 

was intended for highly accurate, all-weather, instantaneous positioning capabilities for the U.S. 

military and its allies. GPS is now freely available to the public; however, accuracy may be 

attenuated for national security purposes. The decreasing cost of GPS receivers combined with 

increasingly accurate operation has allowed this technology to become EPA’s method of choice for 

the acquisition of spatial data. There are similar systems in operation or under development in other 

countries. Russia has a similar system (GLONASS) http://www.glonassianc.rsa.ru/pls/htmldb/f?p=202:1:8312220156118373539 and Europe is working on building a system 

(GALILEO) http://ec.europa.eu/dgs/energy_transport/galileo/index_en.htm. Receivers that will 

handle all three have the label Global Navigation Satellite System (GNSS) 

http://igscb.jpl.nasa.gov/faqs.html#id2839478

 3. Planning and Implementing a GPS Survey

The following sections outline the basic steps involved in systematic planning and conducting a GPS 

survey. In order to complete a successful GPS survey, several steps must be taken prior to using the 

receiver in the field. These steps will apply to the use of any of the various GPS receivers. 

Organizations are encouraged to ensure that personnel are cross-trained to perform GPS coordination 

activities. Alternatively, an organization may consider appointing and training interested staff 

members to serve as GPS coordinators. Most of the steps in the pre-survey and post-survey process 

will be conducted in conjunction with, or entirely by, the GPS coordinator. Equipment may be on 

loan to those employees who have been trained on the use of the GPS receiver. Those who require 

training or feel that retraining is necessary must notify the GPS coordinator well in advance of a 

proposed GPS survey so arrangements can be made for training. 

a. Pre-Survey Planning. The Field Team Leader should develop the following planning 

items in cooperation with the GPS coordinator.
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(1) Define Objectives of the Survey 

It is important to initially establish the ultimate objectives of a GPS survey, including Data 

Quality Objectives (DQOs). Recognition of these objectives early in the project planning 

process will help to focus the rest of the planning phase. The accuracy requirements for the 

positional data must be defined and should be consistent with available program guidance on 

positional accuracy (See EPA National Geospatial Data Policy). In the absence of published 

program guidance on positional accuracy tiers to meet specific program needs, the following 

Interim Quality Categories provide benchmarks for establishing quality controls based on the 

intended use. Data collections for Category I use would dictate more stringent quality 

controls and potentially higher accuracies than Category IV use. See Section 2 “GPS QA 

Project Plan Requirements” for additional background on Interim Quality Categories. 

Category I: For enforcement, litigation, direct support of rules & regulations, projects 

of national significance and highly influential scientific assessment

Category II: Development of rules & regulations and influential scientific information

Category III: Validation, general applications and feasibility studies

Category IV: Screening, exploratory and pure knowledge

From the discussion above, some distinct survey objectives may include: 

• Registration of remotely sensed photography or imagery with ground control locations to 

support enforcement actions. 

• Evaluation of locational data quality of existing data to validate survey maps, and 

• Collection of new data following precise coordinates in a monitoring plan to support rule 

development. 

NOTE: On a case-by-case basis, the user should consider the impact of various factors when 

determining the appropriate QA Category. These factors include, but may not be limited to: 

• National Geospatial Data Policy (NGDP) Accuracy Tiers 

• Dwell Time 

• Number of Monuments, etc. 

QA categorization of Dilution of Precision (DOP) is provided as a suggestion/example 

below – section (7) Equipment Testing and Logistics. 

(2) Define Project Area 

This step is designed to establish the overall project area and define the limits of the survey. 

Maps and/or aerial photos should be utilized extensively to familiarize the crew with the area 

prior to the actual field work. For identifying the study area and surrounding environment, 

7.5-minute topographic maps are ideal. For locating particular sites by address, a local street 

map will be required. A complete understanding of the transportation network in the project 

area will also enable the field crew to maximize the effectiveness of their field time. Much of 

this information may already be available in digital form and may be used directly in 

conjunction with GPS site planning as well as validating the capture of the GPS locations. 
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 (3) Determine Observation Window and Schedule of Operations 

This step involves determining the precise window of satellite availability and scheduling 

accordingly. With approximately 31 GPS satellites and 9 GLONASS satellites available for 

use, satellite links generally are restricted for very short periods of time (usually less than 40 

minutes in a continuous block of time and less than 1 hour during a 12-hour time period) 

during the day, in open environments. However, in cities with many nearby tall buildings, 

GPS signals may be difficult to receive. Updated satellite configuration and orbit information 

can be accessed via the Internet. “Trimble Planning Software” from Trimble Navigation is an 

easy-to-use software program which provides information critical to the various components 

of planning a GPS survey: satellite availability, elevations, azimuths, and Geometric Dilution 

of Precision (GDOP) calculations. However, there are many other easy to use software 

programs to assist users in updating. Some sites may be specifically designed for desktop, 

laptop, or handheld devices. Site sources and URLs may change frequently, therefore, users 

are encouraged to find the best site for their hardware and purpose, and ensure that the source 

of update is recorded in a notebook. For differential corrections against a base station, the 

rover must “see” the same satellites as the base. Accuracy is heavily dependent upon the 

amount of observation time and number of observations taken at each point. It is generally 

agreed that observation time can be reduced by increasing the quality of observation, i.e., 

observing a maximum number of satellites during viewing periods. 

NOTE: “Trimble Planning Software” [2.74 (.zip file)] can be downloaded from 

http://www.trimble.com/planningsoftware_ts.asp 

Download and install “Installation Program for Planning” software. Download the GPSsatellite almanac from Trimble GPS Data Resources. 

If you are in an area with obstructions, select File-Station and click obstacles to enter the 

elevation and azimuth to define the obstruction. You should then be able to display the DOP 

relating to that location to better plan your survey. If you are occupying multiple stations at 

the same time, use File – Multistation in addition to defining the information for each station. 

(4) Establish Control Configuration 

For high accuracy work, generally sub-meter range, known control points and/or benchmarks 

should be located for both horizontal and vertical control. This is usually accomplished by 

researching the records of various federal, state, and local agencies such as the National 

Geodetic Survey (NGS) or the state geodetic survey. It is advisable to have, if possible, at 

least two control points each for both vertical and horizontal positions so that there is a 

double check for all control locations. Vertical accuracy is typically half of the horizontal 

accuracy. Any additional control points may be done by using centimeter GPS. NGS 

benchmark information can be obtained at http://www.ngs.noaa.gov. 

NOTE: When high accuracy readings, such as sub-meter range, are required for a project, 

such as a Category I, the user must have substantial technical know-how, perhaps high-end 

GPS hardware and definitely advance preparation. For the Category I project types, users 

may consider contracting for professional land surveyor services. Data obtained by noncertified personnel may be inadmissible in litigation. Project Officers are encouraged to 

contact their local Office of General Council for consultation regarding concerns of 

admissibility. 
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It is important that the reference datum within which the monument is located be defined. 

For horizontal coordinates, the North American Datum of 1927 (NAD 27) or the newer 

Datum of 1983 (NAD 83) will be specified. For vertical control coordinates, the National 

Geodetic Vertical Datum of 1929 (NGVD 29) or the new North American Vertical Datum of 

1988 (NAVD 88) will be referenced. If the NGS has redefined the benchmark coordinates to 

correspond to the newer datums, coordinates will be available for both datums. In translating 

GPS elevations to vertical elevations, the geoid used should be identified. 

http://www.esri.com/news/arcuser/0703/geoid1of3.html; 

http://www.ngs.noaa.gov/GEOID/

(5) Select Survey Locations 

Obtain a list of the facilities or features targeted for data collection. One suggested approach is to 

organize the site lists alphabetically by city and alphabetically by street name within each city as 

well as by zip code. This approach will facilitate initial route planning to visit each survey 

location and serve as a master list. If possible, plot the general location on a field map and 

highlight a local street map to serve as a general navigation aid. Similarly, project personnel 

should also plot potential base stations to serve as control points on a 7.5-minute topographic map 

and local street map. The survey points/areas should have continuous and direct line-of-site to the 

path of the satellites in the sky.

If the survey point to be obtained is located on private property, care should be taken to pursue 

appropriate notification and access protocol. This includes preparation of a letter of introduction 

and formal contact with the property owner/manager. 

(6) Coordinate Pre-Survey Plans 

The Field Team Leader should contact the GPS Coordinator to identify and discuss the following 

items prior the GPS survey: 

• Objectives. Objectives of the survey, particularly Data Quality Objectives since DQOs 

will highlight required data accuracies (sub-meter, 1-5 meters) and in turn, dictate the 

type of equipment needed. 

• Identification. Identification of the numbers of features to be mapped and time allotted 

for the survey. 

• Availability. The availability of the GPS equipment for the required dates. 

• Features. What features will be mapped, sample point location identification, and how 

they should be represented (points, lines, areas). 

• Checklist. A checklist of each feature to be mapped so that none will be overlooked in 

the field. 

• Site Maps. Site maps for determining survey location with the identification features to 

be mapped and mapping sequence. 

• Reconnaissance. Determine the presence of any obstructions to satellite signals such as 

buildings or tree canopies. 

• Data Format and Storage. Data capture requirements and data format to facilitate postprocessing at the conclusion of the survey. 
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(7) Equipment Testing and Logistics 

Action items for equipment testing and logistics include determination of equipment availability 

(laptop PDA, GPS units, and transport vehicle), checking equipment for necessary repair and 

maintenance (batteries charged in PDA and GPS unit, laptop or PDA loaded with necessary 

software and map data), and ensuring that the receiver is functioning properly. Operation manuals 

provided by the vendor should be referenced to complete system checks on the equipment. 

Modern GPS units contain many settings that can serve as quality checks during data acquisition. 

For instance, a minimum number of visible satellites can be specified for data acquisition. The 

unit will provide a warning signal if less than the minimum specified are available. Four satellites 

in view are the minimum required, but additional satellites can provide the receiver with stronger 

signals to select from and perhaps better geometry for calculation. GPS receivers can also 

calculate a DOP value for horizontal (HDOP), for time (TDOP) and general position (PDOP). 

Position Dilution of Precision (PDOP) is most often referenced with lower values leading to more 

accurate measures. PDOP values of 6 or less are generally acceptable and limits on PDOP can be 

programmed into the unit or software that interfaces with the receiver. See table titled DOP 

Values in Relation to Data Quality Categories below: 

NOTE: The Quality Categories in the following table are suggested. Project impact or other 

factors may supersede the information in the table. 

DOP Values in Relation to Quality Categories 

DOP 

Value 

Rating Description Suggested 

for Quality 

Category 

1 Ideal Highest possible confidence 

level. I 

2 - 3 Excellent Meets all but most demanding 

needs. I or II 

4 - 6 Good Appropriate for most needs. II, III, or IV 

7 - 8 Moderate For less demanding uses. 

Positional measurements 

could be used for calculations, 

but the fix quality could still 

be improved. A more open 

view of the sky is 

recommended. 

IV 

9 - 20 Fair Low confidence level. 

Positional measurements 

should be discarded or used 

only to indicate a very rough 

estimate of the current 

location. 

Not recommended 

> 20 Poor Very low confidence level. 

Measurements are inaccurate 

by as much as half a football 

field and should be discarded. 

Not recommended 
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Once the equipment is tested, the team can collect and pack the field survey equipment. In 

addition to the above items, experienced crews carry everything from a compass and tape 

measure to manuals, almanac printouts and first aid packs. 

(8) Prepare the Quality Assurance Project Plan 

Upon conclusion of the planning and coordination in items (1) through (7), the Field Team 

Leader will be in position to develop the QA Project Plan. Requirements for the preparation 

of the QA Project Plan are stated in EPA Requirements for Quality Assurance Project Plans, 

EPA QA/R2, March 2001 (Reissued May 2006). Additional guidance for developing a 

Geospatial QA Project Plan is found in Section 2. 

b. Survey Execution. The actual GPS survey consists of:

(1) Establishing a Schedule of Operations 

This step involves determining the window of satellite configuration availability and 

scheduling the GPS sessions. The schedule is dependent on the size of the crew, the level of 

accuracy desired, and the logistics of setup and travel between control points. Maximum data 

quality and collection efficiency can be obtained by arranging data collection periods to 

coincide with periods of 3-D or better satellite visibility. 

(2) Pre-Survey: The Day Before 

Plan to arrive at the field site the day before the survey. Charge all batteries, make note if 

GPS unit(s) can be charged through the automobile. Many GPS collection systems utilize a 

battery system which requires either 8-hour or overnight charging. Review the travel routes 

to survey sites and base stations, if required, and coordinate with local personnel. Review use 

of unfamiliar equipment and understanding of procedures. 

(3) Pre-data Collection: Establishing a Base Control Station(s) 

The type of survey will dictate if any base control stations in the field are required. If required 

and the location(s) is not secure or if the data collection period is particularly long, part of the 

survey crew may be required to remain at the site. Logistical considerations will need to be 

scheduled, i.e., shut down periods for downloading files, changing battery packs, and when to 

terminate collection. Once a setup at a base station begins, the GPS units will need to be 

initialized. Depending upon the location and familiarity with equipment, this activity can take 

anywhere from a few minutes to a couple of hours. 

(4) Data Collection: Performing the GPS Survey 

The crew must warm up, check, and program the receiver for proper operation. Most vendors 

currently recommend collecting fixes for discrete point data for a period of 3-5 minutes, at 1- 

or 2-second intervals. Vendor documentation should be consulted for the recommended time 

on station and sample interval to obtain the most accurate results. 

Depending on the unit being utilized, sufficient battery power must be available. For high 

accuracy work, the receiving antenna should be leveled on a tripod and centered exactly over 

the control point location. Log sheets containing critical information on position, weather, 

timing, height of instrument, and local coordinates must be maintained. Once the session is 

completed, the receiving equipment must be disassembled and stored. The log and tape files 

should then be documented and saved. If the survey to be performed will span numerous 
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days, it is likely that the data will be transferred from the GPS to a laptop PC with some 

regularity. Data from the base station as well as the roving unit will need to be collected with 

equal frequency. 

c. Data Assessment, Processing and Validation. Post-processing should be conducted 

after returning from the field. Tools for post-processing are more easily used and controlled 

in an office environment. The common steps in post-processing are transferring the data from 

the field to office workstations, conducting the initial stages of processing, computation of the 

solutions for critical factors, data conversion for use in a GIS, and the final documentation 

and reporting. Each of these stages is discussed in detail below. Data assessment and 

validation should integrate in each stage. 

(1) Data Transfer 

There are currently two common methods of collecting data in the field: using a GPS unit 

with a data logger or using a GPS unit attached to a laptop/notebook/PDA computer. With the 

latter method some users subsequently perform all processing directly on the same device. 

More commonly, data are transferred into a computer. This consists of reading the raw data 

from the GPS unit into a structured data base for processing. As with any computer data, 

backup copies should be made immediately. Validation should consist of reviewing the 

contents of the data logger or computer file against the survey plan and field notes to ensure 

that the data transfer has occurred properly and that file and directory names are adequate to 

link the data to specific field operations or features. 

 (2) Data Assessment and Initial Processing 

The electronic GPS data stream may not be immediately useable. It normally consists of 

satellite navigation messages, phase measurements, user input field data and other 

information that must be transferred to various files for processing before computations can 

be accomplished. Depending upon the hardware and software vendor, many of these 

operations are transparent to the user. 

In some instances, depending on the type of maintenance and upgrades that are going on to 

the NAVSTAR constellation at the time of the survey, utilization of the actual ephemeris 

rather than the ephemeris projected prior to the survey date may improve solution accuracy. 

Actual ephemerides are available 2 weeks after a given survey date. 

In the data screening and editing, there are at least three considerations that might be taken in 

editing. Outlier position data can be removed from a data file. This editing should be guided 

by establishing an absolute deviation threshold, using the mean coordinate as a reference. The 

threshold criteria might be varied to determine the sensitivity of the solutions to this editing. 

Data points collected immediately after a break in the data stream, such as in the event of 

masking, should be edited out because these positions will be less reliable. 

The majority of processing operations are typically performed “automatically” by the 

application software. Occasionally, the scientist (or operator) may need to override automatic 

computer operations. In these instances, scientist (or operator) should document the 

judgments made and identify the manual operations in the appropriate notebook.

(3) Computation 

This component uses the preprocessed data to compute the network of sites and give a full 

solution showing geographical coordinates (latitude, longitude and ellipsoidal height), 
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distances of the vectors between each pair of sites in the network, and several assessments of 

accuracy of the various transformations and residuals of critical computations. This is usually 

accomplished by the vendor post-processing software and may be transparent to the user. 

(4) Data Conversion to GIS 

Data conversion is accomplished by use of data export utilities provided by the GPS vendor. 

These utilities should accompany the data processing software packaged with the GPS 

equipment. Example formats are: ArcView, ArcGIS, dBase, ASCII, MapInfo, AutoCAD, etc. 

Before exporting, ensure that the correct coordinate system and datums are chosen. The 

default coordinate system should be the Geographic Coordinate System which provides 

unprojected latitude/longitude values. The default datum is NAD83 for horizontal coordinates 

and NAVD88 for vertical coordinates. Note that GPS units initially capture data using the 

WGS84 horizontal datum but can be usually converted to the NAD83 datum during the data 

export process. Care should be taken in reporting the proper datum upon completion of the 

conversion process. 

(5) Metadata Documentation and Reporting 

The documentation requirements for spatial data are established in the Agency’s Geospatial 

Metadata Technical Specification v. 1.0, November 2007. This data specification draws 

elements from both the EPA Geospatial Data Policy and the Federal Geographic Data 

Committee’s (FGDC) Content Standard for Digital Geospatial Metadata, and identifies 

metadata elements that EPA views as essential in properly documenting geospatial metadata. 

The reporting of spatial information and metadata is addressed in EPA’s National Geospatial 

Data Policy and EPA’s Geospatial Metadata Technical Specification, Management, Version 

1.0, November 2, 2007. A Metadata Editor Tool has been developed by EPA to simplify the 

documentation process. The aforementioned documents and tools are available for download 

from EPA’s GeoData Gateway at http://geogateway.epa.gov. Other tools are under 

development such as the GeoToolkit to facilitate reporting geospatial data to EPA via EPA’s 

Central Data Exchange (CDX). Spatial data submitted to the Exchange will be loaded into 

EPA’s Locational Reference Table for use by EPA, EPA partners and the public. Access 

restrictions can be specified in the metadata. 

4. References 

FGDC-STD-001-1998, Content Standard for Digital Geospatial Metadata, Federal Geographic Data 

Committee, June 1998. 

FGDC-STD-007.1-1998, Geospatial Positioning Accuracy Standards Part 1: Reporting 

Methodology, Federal Geographic Data Committee, June 1998.

EPA Latitude Longitude Data Standard, Standard Number EX000017.2, January 6, 2006. 

http://www.epa.gov/edr/LatLongStandard_08112006.pdf

EPA, National Geospatial Data Policy, Office of Environmental Information, August 2005. 

http://www.epa.gov/irmpoli8/ciopolicy/2121.pdf
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EPA, Geospatial Metadata Technical Specification v. 1.0, November 2, 2007. 

http://geodata.epa.gov/docs/EPA_Geospatial_Metadata_Technical_Specification_v1_11_2_2007.pdf

EPA, Guidance for Geospatial Data Quality Assurance Project Plans (QA/G-5G), March 2003 

http://www.epa.gov/nerlesd1/gqc/pdf/g5g-final.pdf

EPA, Global Positioning Systems – Technical Implementation Guidance, Revision 2, Office of 

Environmental Information, October 2006. 

http://www.epa.gov/oei/pdf/GPS-TIG.pdf

Attachments: Attachment 1, GPS Pre-Survey Checklist 
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Attachment 1

GPS Pre-Survey Checklist 

Pre-Survey Checklist 

 Obtain List of Facilities 

 Obtain Current GPS-Satellite Almanac 

 Call Coast Guard to Verify Satellite Availability 

 Obtain Control Points from NGS or Local Source 

 Obtain 7.5-min. Topographic Maps 

 Obtain Local Street Maps 

 Prepare Letter of Introduction 

 Collect and Pack Field Equipment 

 

Field Equipment

 GPS Equipment 

 Laptop or Other Field Computer 

 7.5-min. Maps 

 Aerial Photo if Available 

Camera [Digital cameras that can synchronize the images with the latitude / longitude 

field data are recommended] 

 Film [or Memory Stick] 

 Compass 

 Tape Measure 

 Binoculars 

 Field Forms 

 Clip Board 

 Calculator 

 GPS Hardware/Software Manuals 

 Mini Tape Recorder 

 Hard Copy of GPS-Satellite Almanac 

 Rain Gear 

 Two-way Radio Communication (i.e., CB, cellular phone, etc.) 

 

Last Minute Checks

 Charge Batteries 

 Verify GPS-Satellite Almanac 

 Target Travel Route 

 

In the Field Checks

 Find Base Stations 

 Initialize Equipment 

 Begin Collecting Data 
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Section 2 

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GPS Quality Assurance Project Plan (QAPP) Requirements 
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Table of Contents 

Purpose..........................................................................................................................................................1 

Background...................................................................................................................................................1 

EPA QA Policy..........................................................................................................................................1 

EPA QA/QC Requirements and Guidelines ..............................................................................................1 

Uniform Federal Policy for QA Project Plans...........................................................................................1 

Spatial QA Project Plan Considerations .......................................................................................................2 

Components of a QA Project Plan.............................................................................................................2 

Group A. Project Management ..................................................................................................................2 

Group B. Data Generation and Acquisition...............................................................................................2 

Group C. Assessment and Oversight .........................................................................................................2 

Group D. Data Validation and Usability ...................................................................................................2 

Graded Approach.......................................................................................................................................3 

Category I ..................................................................................................................................................3 

Category II.................................................................................................................................................4 

Category III ...............................................................................................................................................4 

Category IV ...............................................................................................................................................4 

Generic vs. Project-Specific QA Project Plans..........................................................................................4 

Enforcement Considerations......................................................................................................................4 

QA Project Plans – Quality Management Plans – GPS Template ................................................................5 

Division and Office Quality Management Plans ......................................................................................5 

Use of the GPS QAPP Template ...............................................................................................................5 
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1. Purpose: This Quality Assurance Project Plan (QAPP) Template is designed to provide an outline 

for typical Global Positioning System (GPS) data acquisition operations in a field environment. It is 

intended for use as guidance by those who plan and carry out GPS data acquisition projects on behalf 

of the EPA. The GPS QAPP Template as presented below may be tailored to match the particular 

requirements of approved Quality Management Plans (QMPs). Tailored templates may then be used 

repeatedly to provide quality management planning for similar GPS data collections.

2. Background: 

a. EPA QA Policy

The root QA document, from which other QA documents applicable to the collection and disposition 

of GPS data are based, is EPA Order 5360.1 A2 (2000), Policy and Program Requirements for the 

Mandatory Agency-wide Quality System, and EPA Manual 5360 A1 (2000), EPA Quality Manual for 

Environmental Programs. These documents cover environmental data,2

 including any field or 

laboratory measurements or information that describes location and information compiled from other 

sources, such as data bases (e.g., georeferenced data) or the literature (maps), under their 

requirements. Three of the applicable requirements are: 

• The use of a systematic planning approach to develop acceptance or performance criteria for 

all work covered by the EPA Order. See Section 3.3.8 of the EPA Quality Manual for 

Environmental Programs, and Section 3 of this SOP; 

• The approval of Quality Assurance Project Plans (QAPPs), or equivalent documents defined 

by a division or office QMP, for all applicable projects and tasks involving environmental 

data with review and approval having been made by the EPA QA Manager (or authorized 

representative defined in the QMP); see Chapter 5 of the EPA Quality Manual for 

Environmental Programs; and 

• Assessment of existing data, when used to support Agency decisions or other secondary 

purposes, to verify that they are of sufficient quantity and adequate quality for their intended 

use.

b. EPA QA/QC Requirements and Guidelines. Key documents for use in developing spatial 

QAPPs include EPA Requirements for Quality Assurance Project Plans (QA/R-5), March 2001

(reissued May 2006), and the Guidance for Geospatial Data Quality Assurance Project 

Plans (QA/G-5G), March 2003. The latter document is a useful guideline devoted to the technical 

aspects of GPS field measurements and forms much of the basis for this attachment. 

c. Uniform Federal Policy for QA Project Plans. The Uniform Federal Policy for QA Project 

Plans (UFP-QAPP) is a consensus policy voluntarily adopted by the sponsoring federal agencies. It is 

used primarily for the evaluation of federal facilities and will be phased into EPA operations over 

time. This attachment does not specifically address the content or structure of the UFP-QAPPs, 

 

2

Environmental data – any measurements or information that describes environmental processes, location, or 

conditions, ecological or health effects and consequences or the performance of environmental technology. For 

EPA, environmental data included information collected directly from measurements, produced from models, and 

compiled from other sources such as data bases or the literature. 
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although is noted that the UFP-QAPPs contain the same four major groups discussed below. See URL 

http://www.epa.gov/fedfac/documents/qualityassurance.htm for additional documentation.

3. Spatial QA Project Plan Considerations: 

a. Components of a QA Project Plan 

• Group A. Project Management. The elements in this group address the basic area of project 

management, including the project history and objectives, roles and responsibilities of the 

participants, etc. These elements ensure that the project has a defined goal, that the participants 

understand the goal and the approach to be used, and that the planning outputs have been 

documented. Group A elements include: 

A1 Title and Approval Sheet 

A2 Table of Contents 

A3 Distribution List 

A4 Project/Task Organization 

A5 Problem Definition/Background 

A6 Project/Task Description 

A7 Data Quality Objectives and Criteria 

A8 Special Training/Certification 

 A9 Documents and Records 

• Group B. Data Generation and Acquisition. The elements in this group address all aspects 

of project design and implementation. Implementation of these elements ensures that appropriate 

methods for sampling, measurement and analysis, data collection or generation, data handling, 

and QC activities are employed and are properly documented. Group B elements include: 

B1 Collection Process/Field Survey Design 

B2 Data Collection Methods 

B3 Data Handling and Custody 

B4 Analytical Methods 

B5 Quality Control 

B6 Instrument/Equipment Testing, Inspection, and Maintenance 

B7 Instrument/Equipment Calibration and Frequency 

B8 Inspection/Acceptance for Supplies and Consumables 

B9 Nondirect Measurements/Secondary Data Use 

B10 Data Management

• Group C. Assessment and Oversight. The elements in this group address the activities for 

assessing the effectiveness of project implementation and associated QA and QC activities. The

purpose of assessment is to ensure that the QA Project Plan is implemented as prescribed. Group 

C elements consist of: 

C1 Assessments and Response Actions 

C2 Reports to Management

• Group D. Data Validation and Usability. The elements in this group address the QA 

activities that occur after the data collection or generation phase of the project is completed. 
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Implementation of these elements ensures that the data conform to the specified criteria, thus 

achieving the project objectives. Group D elements consist of: 

D1 Data Review, Verification, and Validation 

D2 Verification and Validation Methods 

D3 Reconciliation with User Requirements

b. Graded Approach. The “graded” approach to developing QA Project Plans increases efficiency 

in that QA Project Plan elements are planned to be commensurate with the scope, magnitude, or 

importance of the project itself. Simple, straightforward data collection tasks would require simple, 

straightforward QA Project Plans and plan elements. 

The EPA Quality Staff has left the use of the graded approach to the discretion of those implementing 

it. To facilitate the application of the graded approach, the use of QA Categories is recommended. 

The following definitions were developed from existing QA Category definitions being used in 

various parts of the EPA Office of Research and Development. 

Examples of Graded QA Project Plan Elements 

QAPP 

Element 

Description Simple QA 

Project Plan 

Complex QA 

Project Plan 

A.3.c Sat. Observation Window Not Calculated Calculated 

A.3.d Control Configuration Use DOP Settings Differential Correction 

A.5.a Data Quality Objectives > 10 Meters < 10 Meters 

A.5.b Receiver Performance PDOP < 6 PDOP < 4 

A.5.c Statistical Quality Control Based on Method Based on Testing 

B.1.b Sampling Locations Single Location Multiple Locations 

B.2 Sampling Methods Standard Operations Tailored Operations 

B.5 Quality Control Standard QC Checks Extended QC Checks 

Category I: For Enforcement, Litigation, Direct Support of Rules & Regulations, 

Projects of National Significance, and Highly Influential Scientific 

Assessment

The results from Category I activities may directly and/or immediately support specific Agency rulemaking, enforcement, regulatory, or policy decisions. This category may also include research of 

significant national interest, such as tasks that might be monitored by the Administrator. It may also 

include technology transfer projects for which the data and/or the research by which the data were 

obtained may be critical to the award of a patent or other important commercial or legal decision. 

Category I tasks require the most detailed and rigorous QA and QC activities to ensure both legal and 

scientific defensibility, and will likely require chain-of-custody. This means that the data quality 

objectives (DQOs) and data quality assessments, if required for the project, must be specific (or 

quantitative) and that the extensive quality documentation must include all key measurements. This 

category includes projects that fit the Office of Management and Budget (OMB) peer review 

definition of “highly influential scientific assessment.”

NOTE: Project Officers are encouraged to contact their local Office of General Council during the 

planning stage of the project. 
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Category II: Development of Rules & Regulations, and Influential Scientific 

Information

Category II activities are of high programmatic relevance that, in conjunction with other ongoing or 

planned studies, is expected to provide complementary support of Agency rule-making, regulatory, or 

policy decisions. Chain-of-custody may be required for some projects in this category; however, good 

recordkeeping practices always apply. For example, projects providing data measurement technology 

effectiveness that may be used by a Program Office, but that were not intended for use in 

enforcement. The rigorous standards of Category 1 are not necessarily needed or appropriate, 

although thorough quality documentation must be described and developed over the course of the 

project. 

Category III: Validation, General Applications, and Feasibility Studies

Category III activities provide demonstration or proof of concept projects. Category III activities 

include method validation studies. Chain-of-custody may not be required for this category; however, 

good recordkeeping practices always apply. Small pilot studies, methods development (sampling or 

analytical), process engineering evaluations, etc., that fall into this category require flexible 

approaches; considerable latitude is allowed with respect to the format. Quality documentation 

initially must be described, but may be changed and further developed over the course of the project. 

Category IV: Screening, Exploratory, and Pure Knowledge

Category IV activities are basic, exploratory, conceptual projects to study basic phenomena or issues. 

This includes the characterization of naturally occurring mechanisms. 

c. Generic vs. Project-Specific QA Project Plans. QA Project Plans can be either generic or 

project specific. Generic QA Project Plans are typically used for simple data collections that rely on 

logistically simple, repetitive field methods, the same equipment, post-processing techniques and 

straightforward data verification and validation methods. As an example, the establishment of field 

base stations for GPS differential corrections increases the complexity and would dictate a projectspecific QA Project Plan. Because generic QAPPs are used repetitively, they are typically approved 

periodically rather than project by project. SOPs used to support the generic QAPP should be attached 

to the QAPP.

d. Enforcement Considerations. For GPS surveys where data may be presented as evidence 

during legal proceedings, certain recordkeeping procedures are necessary in order to protect the 

integrity of the data as evidence. The recorded information must be sufficient to recall and describe 

observations and measurements made as well as document the life cycle of the data that is used in 

final products such as reports or court exhibits. Records must be identifiable and secured in a manner 

such that they can be retrieved. Records can include information recorded in logbooks, checklists, 

electronic media, data bases, and digital documents. Important information contained in records 

include: who conducted the GPS survey, data post-processing, and data management; chronological 

information related to the data regarding creation, processing, use, and archival; methods used in 

collecting, processing, distributing, and archiving the data; who had access to the data throughout the 

life cycle of the data; and where the original data and records reside. 
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Chain-of-custody procedures apply when the record of transfer and receipt of samples, data, 

documents, or other evidence is required. Chain-of-custody is a record of accountability that clearly 

identifies the personnel directly in contact with the evidence. The chain-of-custody procedures vary 

for each organization; however, it is important that the procedures are followed in order to maintain 

the integrity of the evidence. Examples of situations where chain-of-custody procedures apply to GPS 

data include activities related to criminal investigations, confidential business information (CBI), 

attorney-client privileged information, grand jury rule 6(e) information, and national security 

information (NSI). Refer to the appropriate evidence management procedure for your organization for 

specific requirements on the handling and custody of GPS data and derived products. 

4. QA Project Plans – Quality Management Plans – GPS Template 

• Division and Office Quality Management Plans. All EPA organizations should have 

developed their own tailored Quality Management Plan (QMP). The QMPs may describe the 

organization’s approach to quality management and identify many of the specifics about timing, 

reporting, resources and approvals. Therefore, in developing QA Project Plans based on the 

following template or other guidance, the author should be completely familiar with the QMP for 

their division and incorporate the division or office policies where appropriate. 

• Use of the GPS QAPP Template. The following template was designed for point data 

collections which are the most common surveys. Surveys to collect polygon or line data would 

require additional modifications in the template. Text in blue font should be replaced with 

appropriate text in regular font. 

Enclosure GPS QAPP Template 
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Section 3 

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GPS Quality Assurance Project Plan (QAPP) Template 

Template Source: 

This template was derived from EPA Guidance for Geospatial Data Quality Assurance Plans, 

EPA QA/G-5g, March 2003 [EPA/240/R-03/003] and tailored for point data collections which are 

the most common surveys. Surveys to collect polygon or line data would require additional 

modifications in the template. 

Please refer to EPA QA/G-5g for definitions, more detailed guidance, clarifications, etc. 

Template Use: 

Text in blue font should be replaced with appropriate text in regular font. Each organization should 

also modify the document control notation located in the upper right-hand corner.
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GPS QUALITY ASSURANCE PROJECT PLAN 

[Title of QAPP Here] 

Division: __________________________ 

Branch: __________________________ 

Section: __________________________ 

Creation Date: [Date original QAPP finalized]

Revision #: [Number of revision]

Date Revised: [Date of last revision] 

Review Cycle: [Applicable to generic QAPPs] 

Project Summary: [Provide a brief 1 or 2 sentence summary]

APPROVALS __________________________________________ 

_________________________ ____________ 

Lead Author(s) of the QAPP, Title Date 

Office Name 

______________________________ _______________ 

Program Office Approving Official Date 

This QA Project Plan is consistent with 

EPA requirements. 

______________________________ ________________ 

Quality Assurance Manager Date 
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[Title of QAPP Here]

TABLE OF CONTENTS ____________________________________ 

Section 

Title and Approval Sheet ................................................................................................................ 1

Table of Contents............................................................................................................................ 3

 

A. Project Management .................................................................................................................. 5

1. Project Distribution List.................................................................................................. 5

2. Project/Task Organization .............................................................................................. 5

3. Problem Definition/Background..................................................................................... 5

4. Project/Task Description................................................................................................. 6

5. Quality Objectives and Survey Measurement Performance Criteria.............................. 6

6. Training/Certification ..................................................................................................... 7

7. Documentation and Records........................................................................................... 7

B. Measurement Data Acquisition.................................................................................................. 7

1. Sampling Process Design................................................................................................ 7

2. Sampling and Image Acquisition Methods..................................................................... 8

3. Sample Handling and Custody........................................................................................ 8

4. Analytical Methods......................................................................................................... 8

5. Quality Control ............................................................................................................... 8

6. Instrument/Equipment Testing, Inspection, and Maintenance Records ......................... 8

7. Instrument Calibration and Frequency............................................................................ 8

8. Inspection/Acceptance Specifications for Supplies and Consumables........................... 8

9. Nondirect Measurements ................................................................................................ 8

10. Data Management ......................................................................................................... 9

C. Assessment/Oversight .............................................................................................................. 10

1. Assessment and Response Actions ............................................................................... 10

2. Reports to Management ................................................................................................ 10

D. Data Validation and Usability.................................................................................................. 11

1. Data Review, Validation, and Verification Criteria...................................................... 11

2. Verification and Validation Methods............................................................................ 11

3. Reconciliation with User Requirements ....................................................................... 11 
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[Title of QAPP Here] 

A. Project Management ___________________________________________ 

1. Project Distribution List 

________________, QA Manager 

________________, Project Manager 

________________, QAPP Writer / Field Team Leader 

________________, GPS Coordinator 

________________, GPS Operator 

________________, GIS Coordinator 

2. Project/Task Organization 

The following individuals and organizations will participate in the project. Their specific roles 

and responsibilities are listed in the table below. The Approving Official exercises supervision 

over the Project Manager and QAPP Writer. The QA Manager is independent of the Approving 

Official, Project Manager, and QAPP Writer. The QA Manager ensures that QA Project Plan is 

consistent with USEPA requirements. 

3. Problem Definition/Background (See SOP, Section 1, 3a. Pre-Survey Planning) 

a. Objectives of the Survey. (State the Objectives of the Survey)

b. Project Area. (Attach Overview Map and describe Project Area) 

c. Observation Window and Schedule of Operations. (State overall schedule)

d. Control Configuration. (Applicable for high accuracy collections) 

Name Organization Role 

 Approving Official 

 QA Manager 

 QAAP Writer 

 Maintains QAPP 

Documents 

 Project Manager 

 GPS Coordinator 

 Field Team Leader 

 GPS Operator 

 Data User 
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4. Project/Task Description 

Task Output Outcome Schedule 

Example Tasks 

Follow 

Edit & Add as 

Appropriate 

 

Develop PreSurvey Plan Pre-Survey Plan Understand the Survey 

Parameters 5 Days 

Develop QA 

Project Plan 

Approved QA Project 

Plan 

Quality Assured Project 

Implementation 3 Days 

Coordinate PreSurvey Plans Meetings and Survey 

Planning Products 

Identification and 

resolution of issues 3 Days 

Equipment 

Testing & Quality 

Checks 

Log of Testing & 

Quality Checks 

Calibrated & Tested 

Equipment per OEM 

Manual 

2 Days 

Safety Briefing 

for Field Crew 

Safety Checklist Understand Risks and 

Proper Safety Measures 

2 Hours 

Move to Field 

Location 

Travel Logs Safe Arrival at Field 

Survey Site 

Variable 

Data Collection Field & Data Logs GPS Data Backed up on 

Laptop Computers 

Variable 

Move to Home 

Location 

Travel Logs Safe Arrival at Home 

Location 

Variable 

Data Assessment 

& Processing 

Data in GIS 

Electronic Format 

Quality Assured Data in 

Proper Format 2 Days 

Data 

Documentation 

Metadata Record in 

Proper Format 

Data Documented per 

EPA Guidelines 

4 Hours 

Internal Data 

Review Approval Record Approved Locational Data for Distribution 

Variable 

Publish GPS Data 

to Locational 

Reference Table 

(LRT) 

Transaction Record 

for Data Submission 

Data Forwarded to LRT 

for Secondary Data Users 

2 Hours 

Develop Final 

Project Report 

Approved Final 

Project Report 

Document & Understand 

Project Results 

Variable

5. Quality Objectives and Survey Measurement Performance Criteria 

a. Data Quality Objectives. The GPS survey will utilize the [Brand, Model] receiver in 

the GPS Code, Standard Position Mode to obtain facility latitude/longitude values within 

10 meters of true locations at the 95% confidence level. This level of accuracy is 

consistent with Tier 3 described in the EPA National Geospatial Data Policy. 

b. Receiver Performance Criteria. The [Brand, Model] will be set to capture data 

provided that at least four satellites are in view and the Position Dilution of Precision 

(PDOP) value remains at 6 or below. The receiver will be set to provide audible or visual 
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warnings when the quality settings are exceeded. Sample interval and time on station will 

be consistent with [Brand, Model] Manual recommendations. Generally, this will require 

3 minutes on each station sampling at 2-second intervals. 

c. Statistical Quality Control Check. Post-processing the GPS data will be 

accomplished using the vendor’s software package operating on a local workstation. The 

higher end software package will perform statistical analyses on the point data 

downloaded from the GPS receiver. For 10-meter data accuracy, any data points with a 

standard deviation of 3 meters or more will be a basis to exclude that data point from the 

collection. Ideally, the standard deviation for 10-meter accuracy data should be 1 meter 

or less at the 95% confidence level.

 

6. Training/Certification 

a. Training. In addition to field safety training, the GPS Operator must complete a 

general GPS course, become familiar with the receiver’s Operation Manual, and test the 

receiver under real operating conditions for familiarity with all receiver settings, options 

and operations prior to actual field use. 

b. Certification. Not applicable. 

7. Documentation and Records 

Documentation consists of the outputs described in section A.4 above. The GPS Coordinator is 

responsible for development of the metadata documentation. The Project Manager is responsible 

for developing the Final Project Report which will reference the planning and performance 

documents. The documents will be maintained and managed per EPA Records Management 

Guidelines. The QA Manager will maintain a copy of the approved QA Project Plan and any 

amendments. 

B. Measurement Data Acquisition ________________________________ 

1. Sampling Process Design 

a. General. Discuss the overall approach to the data acquisition survey in terms of the 

purpose of the survey, the number of locations to visit, the operational area (refer to map 

to discuss operational area), equipment, timing and team composition.

b. Sampling Locations. Discuss the sampling locations in detail concerning the 

measurement sites (e.g., Main Entrance, Receiving Dock, Sub-Facility), need for access 

clearance if appropriate, and control points if applicable. Establish a data dictionary and a 

list of site attributes to be collected. Identify any checklists. 
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2. Sampling and Image Acquisition Methods. Discuss the equipment to be employed, the 

time on station and sample interval, receiver settings and mode of operation. Discuss the data 

logs and attribute documentation methods (date recorded, time recorded, and correction status). 

Identify any checklists. Identify corrective action steps should the receivers fail or malfunction in 

the field.

3. Sample Handling and Custody. Discuss the method for protecting the data and 

establishing a verifiable record of collection, post-processing and reporting the data. If 

supporting an enforcement matter or other sensitive situation, discuss any special recordkeeping 

provisions that apply in collecting, processing and reporting the data, such as chain-of-custody 

and computer security. 

4. Analytical Methods. The GPS unit samples multiple satellite signals within its line of sight 

and internally processes the signals using triangulation algorithms to produce latitude/longitude 

and altitude values for the station under evaluation. The GPS unit is capable of storing the 

latitude/longitude and altitude values along with other relevant GPS data, including the internal 

unit settings. Record the GPS make/model information to ensure that triangulation algorithm and 

other analytical methods can be traced through the manufacturer if necessary. 

 

5. Quality Control. Quality Control will be achieved by assuring that the GPS receiver 

performance criteria under section A.5 above are met at all times. Statistical checks will be 

performed on the data during the post-processing phase and the data will be compared to known 

map coordinates and features using TIGER/Line files, USGS topographic maps, the Tele Atlas 

data base and other appropriate map sources of known quality. 

 

6. Instrument/Equipment Testing, Inspection, and Maintenance Records. Equipment 

testing will be accomplished by the GPS Operator prior to, during and after field use. Built-in 

equipment diagnostics and functionality checks will be utilized in accordance with the operation 

manuals. Results will be reported in pre-survey, field and post-processing logs. Issues will be 

documented with the GPS Coordinator or equipment owner. 

7. Instrument Calibration and Frequency. GPS receivers cannot be calibrated. However, a 

number of settings can be changed (maximum PDOP, signal-to-noise ratio, filter coefficient, 

etc.) which will affect operation of the unit. In general, manufacturer default settings will be 

employed for optimum data accuracy. 

8. Inspection/Acceptance Specifications for Supplies and Consumables. The primary 

consumables for GPS operations are batteries. During the equipment testing, inspection and 

maintenance periods, batteries will be examined by the GPS Operator for functionality, charge 

and compatibility with manufacturer’s specifications. Fully charged, backup batteries will be 

taken to the field for use when recharging is not an option. 

9. Nondirect Measurements. The display of survey results will be accomplished by 

overlaying the collected points on map features of comparable quality. This provides a road 

network, topographic features and other map elements that can place the collected points in the 
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context of real-world features. This is an additional quality check, since large deviations from 

expected locations would cause the data and processing methods to be rechecked. Standards map 

products of known quality will be used. 

10. Data Management 

a. Data Dictionary. (Define program-specific terminology) 

b. Data Collection Process and Quality Checks. See sections A.5.a and A.5.b above. 

 

c. Data Processing. Post-processing is described in section A.5.c above. 

d. Metadata Preparation. Metadata preparation will be accomplished by the GPS 

Operator upon conclusion of the data processing phase using the EPA, Geospatial 

Metadata Technical Specification v. 1.0, November 2007. 

e. Data Acceptance and Documentation Process. The Project Manager will prepare a 

Data Acceptance Report with an overlay map showing new data collected in the context 

of standard map features (roads, streams, political boundaries) and forward it to the 

Approving Official for review and approval. The Project Manager is also responsible for 

developing the Final Project Report which will reference the planning and performance 

documents (see Outputs, section A.4 above). The documents will be maintained and 

managed per EPA Records Management Guidelines. The QA Manager will maintain a 

copy of the approved QA Project Plan and any amendments. (Option – Data Acceptance 

may be combined with the Final Project Report to eliminate a separate report)

f. Data Storage, Access and Security. Data storage, access and security will follow the 

procedures described in EPA National Geospatial Data Policy sections. 
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C. Assessment/Oversight ___________________________

In all assessment and oversight issues, the individual(s) making assessments and implementing 

actions must be identified in the appropriate records. 

1. Assessment and Response Actions 

 Type Assessment Results Corrective Action 

Project Objectives by Project 

Manager 

Complete / Incomplete / 

Partial 

Redo or Amend Project 

Objectives 

Equipment Testing by GPS 

Operator 

Pass / Fail Repair or Replace 

Data Completeness by 

Project Manager 

Stations Sampled vs. 

Planned Sampling 

Revisit Site or Amend 

Project Objectives 

Data Quality Objectives by 

GPS Operator 

Data Meets / Does Not 

Meet DQO 

Exclude Questionable 

Data Points 

Performance Criteria by GPS 

Operator 

Met / Did Not Meet 

Performance Criteria 

Exclude Questionable 

Data Points 

Statistical Quality Checks by 

GPS Operator 

Met / Did Not Meet 

Standard Deviation 

Exclude Questionable 

Data Points 

Map Overlay Against 

Known Locations by GPS 

Operator 

Good / Poor Fit Against 

Known Locations 

Recheck Acquisition 

and Processing Steps 

2. Reports to Management

 Report Content Frequency 

Project Status Report by 

Project Manager 

Status of Tasks in 

Section A.4 above 

Bi-Weekly Updates 

Data Acceptance Report 

by the GPS Operator 

Data Collection, Quality 

Check Results and 

Processing Results 

Once Upon Completion

Final Project Report by 

Project Manager 

Summary of Project 

Accomplishments 

Once Upon Completion
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D. Data Validation and Usability _____________________

1. Data Review, Validation, and Verification Criteria

Data Element Reviewed By Validation Criteria 

Coordinate Data Project Manager Consistent with Sampling Process 

Design 

Coordinate Data GPS Operator GPS Mode Matches Field Log & 

GPS Internal Data 

Coordinate Data GPS Operator Default Settings Match GPS Internal 

Data 

Coordinate Data GPS Operator Standard Deviation below 3 Meters 

for Acceptance 

Coordinate Data GPS Operator Good Fit when Data Plotted against 

Known Locations 

Coordinate Data GPS Operator Meets National Map Accuracy 

Standards 

Metadata Project Manager Meets EPA Guidelines for Metadata 

Documentation 

2. Verification and Validation Methods

Data Element Validation Method 

Coordinate Data Compare Sampling Process vs. Field Log and Internal 

GPS Log 

Coordinate Data Compare GPS Planned Mode vs. Field Log and Internal 

GPS Log 

Coordinate Data Compare Manufacturer Default Settings vs. Internal GPS 

Log 

Coordinate Data 95% of Coordinate Points fall within National Map 

Accuracy Standards when overlaid on known quality 

map features of similar accuracy 

3. Reconciliation with User Requirements 

The GPS Survey results and products will be evaluated against the Data Quality Objectives 

established and user requirements to determine if any reconciliation is needed. Reconciliation 

concerning the quality, quantity or usability of the data will be reconciled with the user during 
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the data acceptance process. Types of reconciliation may include reduction in the scope of the 

project in terms quality or quantity of data produced in meeting partial user requirements.

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