The significant advances made in interpreting satellite imagery to monitor urban expansion and informal settlements has made important contributions to urban studies and planning. This paper focuses on the under-examined dimensions of how improvements to classifications of urban areas are not only a technical challenge but lie at the society/technology nexus. We examine why three different research groups produced different urban land use classifications of Ho Chi Minh City, Vietnam from remote sensing images. We trace how a confluence of factors including how the technology intersects with field conditions, researcher assumptions and discretionary choices, and institutional norms and agendas shaped the differences in their results. The different spatial facts they produced raises the issue of adapting algorithms for not only technical accuracy but appropriate social use. In the case of detecting informal settlements, our study finds that groundtruthing through fieldwork or collaborative partnerships is needed to not systematically overlook vulnerable populations and misinform urban planning decisions.

在解释卫星图像以监测城市扩展和非正式住区方面取得的重大进展为城市研究和规划做出了重要贡献。本文关注的是未得到充分审视的维度，即如何改善城市分类不仅是一项技术挑战，而且还处在社会/技术联系中。我们研究了为什么三个不同的研究小组根据遥感图像得出了越南胡志明市不同的城市土地利用分类。我们追踪各种因素的融合，包括技术如何与现场条件相交，研究人员的假设和自由选择，制度规范和议程如何影响其结果。他们产生的不同的空间事实提出了不仅要针对技术准确性而且要对社会进行适当使用来适应算法的问题。在发现非正式住区的情况下，我们的研究发现，需要通过实地调查或合作伙伴关系进行实地调查，以免系统地忽视弱势群体并误导城市规划决策。