IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
ferruginous quartzite zone located away from the mineralized 
belt. North is towards top of the image. Banera is slightly above 
the top right corner of the image. 
marked, ferruginous quartzite could not be found during field 
visit. The PAN-sharpened colour ratio composite of TM was 
found to be highly useful during the field visit for locating the 
features. 
6.2 Mapping of Apparent Thermal Inertia 
An attempt has been made to map the Apparent Thermal Inertia 
(ATI) of the rock formations to study the distribution of the 
density of the rock formations vis-à-vis mineralization based on 
the ground-based temperature measurements and TM thermal 
infrared data. Towards this, initially the known mineralized 
area around Tiranga hill has been selected for making the 
ground-based temperature measurements across and along the 
strike of the mineralized ferruginous quartzite. Temperature 
measurements were carried out using Telatemp Infrared 
Thermometer (AG-42) during — (i) pre-dawn to early morning 
(0500 to 0700 hrs) and (ii) late afternoon (1700 to 1900 hrs) — 
at the same locations. The resolution and accuracy of the 
instrument used for temperature measurements were 0.1 °C and 
+/- 0.5 °C, respectively. Positional measurements were made 
using GPS (Magellan make). The temperature difference (AT) 
measured across (A-A’ profile) and along (B-B' profile) the 
strike of the mineralized ferruginous quartzite of Tiranga hill is 
shown in Figure-2. The profile A-A', along which different 
*ock types (viz. quartzite, calc gneisses, marble and calcareous 
quartz biotite schist) are exposed, shows a broad low of AT (or 
higher thermal inertia) for ferruginous quartzite due to its 
higher density as compared to the surrounding rocks. For 
the other rocks, AT varies depending upon the type of rock 
and surface cover. Whereas, along the profile B-B', the low AT 
zones may indicate the presence of higher density material (or 
concentration of ore minerals) as the rock type is same and is 
exposed on the surface. 
Fm be Fae 
Figure-2 PAN-sharpened colour ratio composite (3/1 5/4 5/7 = 
These ground-based temperature observations were then 
compared with the TM thermal infrared (band 6) data. It has 
been found that the lows and highs of ground-based AT match 
fairly well with the TM band 6 data, especially along the profile 
B-B’. Based on this observation, an attempt has been made to 
map the Apparent Thermal Inertia (ATI) for the entire study 
area. It involved the following steps — 
(1) Conversion of TM band 6 DNs to temperature, 
(ii) Establishing a regression model between TM 
band 6-derived temperature and AT based on the 
measurements made along profile B-B', 
(iii) Calculation of albedo from TM band 2 and 
(iv) Calculation of ATI. 
The coincidence of high thermal inertia zones and the presence 
of ferruginous quartzite, the mineralized horizon in the study 
area, may indicate the presence of higher density material (and 
probably mineralization). Based on this philosophy, after 
overlaying the high thermal inertia zones over the geological 
maps, four zones having high thermal inertia have been found 
as shown in Figure-3. Out of these four zones, significant ore 
reserves have already been proved in three zones and in 
the 
fourth zone, there are indications of mineralization (Patel, 
1987). 
It is important to mention here the following. Though, the 
correlation coefficient for the regression model between TM 
band 6-derived temperature and ground-based AT is not very 
high (R=0.67), but the ATI map prepared in this way will give 
some idea about the presence of higher thermal inertia zones 
and hence the higher density material. The profile B-B' has 
been used for making the regression model due to better 
correlation between TM band 6-derived temperature and 
ground-based AT and also to avoid the effect of differential 
solar illumination. The temperatures derived from the TM band 
  
R ror a 
  
R G B) image of TM around Tiranga Hill showing variation 
in AT along A-A' and B-B' profiles based on ground-measured temperatures. Image covers 2 km x 2.5 km area approx. 
North is towards top of the image. 
492