BRAZILIAN QUALITY CONTROL SYSTEMS FOR DIGITAL PHOTOGRAMMETRY
MAPPING PRODUCTION
S. S. Sato*. I. da Silya ®
“Escola de Engenharia de Säo Carlos, Universidade de Säo Paulo, Säo Paulo, Brazil — “sssato@terra.com.br;
bi.
leicabr@attglobal.net
Commission II, WG IV/4
KEY WORDS: Photogrammetry, Quality Control System, Digital Photogrammetric Mapping Production, Standardization.
ABSTRACT:
This paper discusses a quality control system developed to be applied to the digital photogrammetric process for Brazilian spatial
data production. The developed quality control system is directed to aerial surveying companies and at same time it can be used as
guidelines for specifications for photogrammetric products like aerial triangulation, DTM, orthophoto and mosaic generation, data
collection and so on. It is based on quality management standards ISO 9000 and in the Swiss Standards Guidelines and the others. In
order to detect the main problems arising during the photogrammetric products production, several aerial surveying companies as
well as their customers were asked to participate in a surveying. In this way a significant part of the difficulties of photogrammetric
products had been identified and analyzed and correction have been proposed to meet customers and company expectations. The
main sources of errors are identified and analyzed in order to be corrected or reduced in the control quality system. During research
some specific problems had been found, as for instance, quality control on the image acquisition process. In that case, the probable
causes in the process had been investigated for the inclusion of corrective actions. Also, each step of the process was investigated
and controlled in order to obtain individual quality parameters that, collectively, are able to assure the quality of the final product,
mostly considering aspects of precision and accuracy requirements for mapping production based on the customer's expectations.
One of the main functions of the developed control quality systems is for implementation of the corrective actions in the procedure
of production process.
1. INTRODUCTION Being thus, after months in the wait for his product, the
customer can be surprised by a cartographic product with PEC
For long time, several categories of companies in the area of class C and not class A as expected and perhaps without
geo-technologies have been seeking for the standardization of guarantees of the attributes accuracy, logical consistency and
their products in order to obtain the quality certification ISO the completeness as normally found in FGDS, CEN, ISO/TC
9000. Among them we can include the aerial survey companies. 211 standards. And the problem can be bigger if, for instance, it
For those companies, it was verified that besides their needs for occurs in the production of orthophotos, when the customer can
quality certification there are also some needs to adequate their be surprised with the aspect of the colorful bedspread of
products to the customer’s expectations. In order to identify the remnants.
problems involved in such area we implemented a research
whose results are presented in Figure 1. The control quality accomplished only in the end of the process
i is considered highly risky for the aerial survey companies. If
| PRODUCTION PROBLEMS CLASS some error occurred during the productive chain, it will only be
BE detected after the edited maps testing. The products can be
accurate but not necessarily it means that the customer’s
B expectations has been attainted.
| gg Ahead of this context, an PhD research was developed focusing
on the development and the implementation of a system of
quality control of digital photogrammetric processes whose
| FP objective is to assure quality enough in each step of the
| photogrammetric production and mainly to guarantee
| | I^ customer's satisfaction. A partial result of that research is
| m Standarlization and Quality presented in this paper.
EN 2. QUALITY CONTROL SYSTEMS
0 Costs & Political | ; =
O Inadequated = The main objective of the proposed quality control system is to
obtain a continuous production chain with “zero error”. The
Figure 1 : s à :
e main characteristics of that quality control system are:
The Brazilian national quality indicator for cartographic
product was officially regulated in 1984 and named as Standard
of Cartographic Accuracy (PEC). The critical factor in this
context is the cartographic product quality being verified only
after the elaboration of the maps or the cartographic database.
eQuality control for every activity;
eldentification of systematic errors in the production
process;
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