## 3 Results and Discussion
### Photographic Documentation  
First of all we must explain that this kind of fieldwork, especially taking pictures and bringing curious students into such environment, is only feasible and responsible because of the high reputation and active shelter of GK. Inside the GK villages and even at the fringes one feels safe and very welcome.  
In 2010, we have tried to cover entire slum upgrading areas. This systematic photo documentation turned out to be a complicated undertaking, e.g., _Baseco_ has a dimension of several hectares. Many situations in the narrow lanes required acrobatic climbing to allow overlapping image shots - the precision of the attained image material is accordingly limited. Together with all the photos and sketches of the students, the field works creates gigabytes of snapshots and raw image material for the design process and Grassroots GIS. Freehand photographing without tripod is fast, flexible and adequate in narrow and congested slum environments. But the gained material is difficult to process automatically for linear panoramas, because of irregular picture intervals and shooting angles. In 2011, we decided to be more selective and just documented parts that deserved closer attention for design interventions. The iPhone App _360 Panorama_ allowed us - via an ingenious real-time panorama painting technique - to create on-site, effective geo-referenced 360\({}^{\circ}\) views (Figure 11) despite the omnipresent hindrances and stumbling blocks in the informal environment, which render all too systematic and exact photo documentations virtually impossible. No chance for finicky fiddling on squatter or ex-squatter territory. The tightness and density of informal settlements would afford an ultra-wide-angle lens to allow photographing of complete facades - currently unaccomplishable for an iPhone-sized camera. Also the photo quality suffers from high image contrast or in low light conditions. We repeatedly thought that an App with a comparable comfort and simplicity for the creation of linear (long and flat) panoramas would be extremely helpful for analytic work in the context of informal settlements. The _360 Panorama_ App is one of the most simple and efficient fieldwork tools we found so far, but it should feature a better exposure compensation for strong light contrast in outdoor situations. And it would be good - especially for landscape architects - if the App could record a bigger visible portion of sky and ground.  
In 2012, we consider to test Microsoft _Photosynth_ App [17] for the interactive panorama capture and sharing on _the cloud_. The multi-perspective street slide panorama system _Street Slide_[27] developed by Microsoft Research is able to render linear panoramas of street facades. We tag our current results as \"_Google Street View_ surrogate\", a low-budget, self-made alternative to Street View, wildly handmade but sufficient and bridging the waiting time for the Google (or Microsoft) camera vehicle that never arrives [3].  
As being visible on the panoramas, color plays a crucial role in the GK concept. Slums are dark, sometimes pitch-black. The GK movement tries to guide the poor back to the light and paints all new houses in bright colors. To document these colors, we used the App _Color Set_ (Figure 12), a digital color chart based on the German RAL color systems, which can be used in the field to identify the  
Figure 11: _Google Street View_ surrogate. Panoramas of **(a)** GK _Telus_ and **(b)** adjacent slum neighborhoods, recorded with the _360_ Panorama App.  
exact tint of the GK house walls. Such detailedness is possible but constitutes a theoretical extreme of Grassroots GIS. This goes too far concerning our purposes but we had to test it.